Doc #117 — Surgical Consumable Conservation and Local Production

---

RECOMMENDED ACTIONS — SUMMARY

Immediate (Days 1–14)

1. Inventory all surgical consumable stocks nationally — hospitals, distributors, surgical centres, veterinary surgical supply. [URGENT]
2. Suspend non-essential elective surgery. Preserve consumables for emergency and essential cases. [IMMEDIATE]
3. Implement consumable rationing protocols — minimise disposable use, switch to reusable alternatives where available. [IMMEDIATE]

Short-term (Weeks 2–12)

4. Switch to reusable surgical drapes and gowns. Source fabric, establish laundry/CSSD processing. [URGENT]
5. Audit all autoclaves nationally. Assess condition, identify spare parts needs, train staff in manual operation. [URGENT]
6. Begin surgical instrument maintenance programme. Establish sharpening workshops at each major hospital. [HIGH PRIORITY]
7. Begin training in ether anaesthesia and expanded regional anaesthesia techniques. [HIGH PRIORITY]
8. Reserve chromium salts, iodine stocks, and sulfuric acid for surgical consumable production. [HIGH PRIORITY]

Medium-term (Months 3–12)

9. Establish catgut suture pilot production at one or two centres co-located with meat processing facilities. [PRIORITY]
10. Begin ethanol production for antiseptic use. [PRIORITY]
11. Begin production of wound dressings from NZ wool and harakeke fiber. [PRIORITY]
12. Fabricate drawover ether vaporisers (requires machine shop capability). [PRIORITY]

Long-term (Years 1–5)

13. Scale all local production to meet clinical demand before imported stocks are exhausted. [STRATEGIC]
14. Establish ether production once sulfuric acid is available. [STRATEGIC]
15. Develop seaweed-derived iodine production. [STRATEGIC]
16. Assess and potentially establish sericulture for silk suture production. [STRATEGIC]
17. Develop surgical instrument fabrication capability for long-term replacement. [STRATEGIC]
18. Adapt surgical training curricula for recovery-era techniques and consumables. [STRATEGIC]

---

This document describes the technical pathway for maintaining surgical capability using established historical methods and NZ-available materials. All production processes described here were standard practice within living memory. The challenge is not invention but organised transition — getting from where NZ is to where it needs to be before the gap in supply becomes a gap in capability. Every month of advance preparation compresses that gap.

---

Economic Justification

Program Workforce Requirements

Sustaining surgical consumable capability through the recovery period requires sustained skilled labour across three functional roles:

Biomedical engineering technicians maintain and repair autoclaves, anaesthetic machines, and surgical equipment. Across NZ’s public hospital network — approximately 20 district and regional hospitals plus rural hospitals — maintaining functional sterilisation and anaesthetic infrastructure requires an estimated 60–100 biomedical technicians at sustained operation throughout Phase 1–3. This is approximately 60–100 person-years per year, or 300–500 person-years over a 5-year programme period. NZ’s pre-event biomedical engineering workforce (approximately 500–700 registered practitioners) is adequate in headcount but concentrated in tertiary centres; redistribution to regional facilities is the operational challenge, not absolute numbers.

Textile workers for suture and dressing production represent a new category of clinical supply labour. Catgut suture production co-located with meat processing facilities requires skilled workers for intestine processing, stripping, twisting, and quality testing — estimated 20–40 workers at two to four production centres from Year 1 through Year 5, yielding approximately 100–200 person-years. Wound dressing production from wool and harakeke fibre requires carding, spinning, weaving, cutting, and packing workers — at the scale needed to replace disposable dressings nationally, an estimated 150–300 workers through Phase 2–3, or 300–900 person-years. These are semi-skilled roles that can be filled from NZ’s general workforce with months of on-the-job training; they do not require medical qualifications.

Sterilisation technicians (CSSD staff) process reusable drapes, gowns, instruments, and locally produced consumables. The shift from disposable to reusable materials substantially increases the volume of sterilisation work per case — each reusable drape set requires laundering, inspection, folding, packaging, and autoclaving that a disposable drape eliminates. Estimated additional CSSD labour: 30–50% above pre-event staffing levels sustained through Phase 2–3. Across NZ’s hospital network, this translates to approximately 200–400 additional CSSD person-years over 5 years.

Total programme workforce estimate: 900–2,000 person-years across all three categories over a 5-year sustained programme, with the majority of this labour drawn from NZ’s existing textile, engineering, and healthcare support workforces rather than requiring new specialist training from scratch.

Conservation and Local Production vs. Losing Surgical Capability

The economic comparison is asymmetric and stark.

Cost of the programme: The person-years estimated above represent a real labour allocation — workers redirected from other productive activity to maintain surgical capability. At a rough productivity-equivalent of 2,000 hours per person-year, the programme represents approximately 1.8–4.0 million worker-hours over 5 years. This is significant but not large relative to NZ’s total workforce (approximately 2.6 million employed people pre-event).

Cost of losing surgical capability: Surgery is a capability that determines whether people with specific conditions live or die. The conditions that require emergency surgery under recovery conditions — acute appendicitis, ruptured ectopic pregnancy, caesarean section for obstructed labour, traumatic haemorrhage, bowel obstruction, major infection requiring drainage — have mortality rates of 50–90% when surgery is unavailable and are treated in years, not decades. NZ performs approximately 300,000–400,000 procedures per year under normal conditions; even at a 60% reduction in elective caseload, emergency and essential surgery is likely to run at 60,000–120,000 cases per year through Phase 1–3. Loss of surgical capability for even one year, at an average mortality increase of 20–40% for untreated emergency presentations, represents tens of thousands of preventable deaths annually.

The programme cost — roughly 1,000–2,000 person-years — does not approach the human cost of losing surgical capability. The economic argument is not close.

Breakeven Analysis

Breakeven in a non-market recovery economy is most usefully framed as: at what point does the programme pay back its labour investment in terms of workforce days preserved?

A single emergency appendicectomy that succeeds preserves approximately 20–40 years of working life for a patient in the prime working-age group. At 250 working days per year, one successful appendicectomy preserves 5,000–10,000 working days. The programme labour cost per surgical case maintained (distributing total programme labour across cases performed) is approximately 15–30 person-hours. The ratio is roughly 300:1 in favour of maintaining surgical capability. Breakeven occurs at the first operation. The programme labour investment is recovered many times over within the first months of operation, not at the end of a years-long payback period.

The binding constraints on programme value are not economic return but logistical: whether catgut production is established before suture stocks run out, whether autoclaves are maintained before they fail, whether CSSD staffing is expanded before reusable drape systems are needed. The economic case is a given. The operational case is what demands attention.

Opportunity Cost

Labour directed to surgical consumable maintenance competes primarily with:

• Textile production for clothing and agriculture — the same workers who could produce dressings and sutures could produce clothing (Doc #104) or agricultural textile goods. The competing claim is real but manageable: surgical consumable textile production represents a small fraction of NZ’s total textile labour need, and the two can be sequenced within the same facilities and workforce.
• Biomedical technician time for other medical equipment — the same engineers who maintain autoclaves also maintain imaging equipment, ventilators, and laboratory instruments. Autoclave maintenance must be prioritised, because sterilisation is the enabling infrastructure for surgery rather than a downstream service. Autoclave failure stops surgery; imaging equipment failure impairs diagnosis but does not stop treatment.
• General engineering labour — the broader competing demand from industrial maintenance (Doc #91), power generation (Doc #67), and transport infrastructure. Biomedical engineering is a specialised sub-category; direct competition with general engineering labour is limited.

The opportunity cost of the programme is real and should not be dismissed. The resolution is that surgical capability maintenance has a narrow technical workforce requirement (biomedical engineers, CSSD technicians) that does not substantially overlap with the broader categories of labour needed for agriculture, energy, and transport recovery. The textile worker component competes more directly with other production needs, but the scale involved — a few hundred workers — is not large enough to represent a binding constraint on NZ’s broader textile production capacity.

---

1. NZ’S SURGICAL CONSUMABLE SUPPLY

1.1 What NZ uses and where it comes from

NZ’s public and private hospitals perform approximately 300,000–400,000 surgical procedures per year under normal conditions, ranging from minor day-surgery procedures to major cardiac, orthopaedic, and abdominal operations.¹ Every one of these procedures consumes sterile disposable items manufactured overseas — primarily in Malaysia, Thailand, China, Mexico, the US, and Europe.

Major categories of surgical consumables:

Category	Examples	Annual NZ consumption (estimate)	Manufactured in NZ?
Sutures	Absorbable (polyglactin/Vicryl, poliglecaprone/Monocryl, polyglycolic acid/Dexon), non-absorbable (nylon, polypropylene/Prolene, silk, steel)	~500,000–800,000 packets2	No
Surgical gloves	Sterile latex and nitrile, examination gloves	~5–10 million pairs3	No
Drapes and gowns	Disposable sterile surgical drapes, gowns, and instrument covers	Millions of units	No
Sterile dressings	Gauze pads, combine dressings, adhesive dressings, wound-closure strips	Millions of units	No — some packaged locally from imported materials
Scalpel blades	Disposable blades (sizes 10, 11, 15, 20, 22, 23 are standard)	~200,000–500,000 blades	No
Anaesthetic agents	Sevoflurane, desflurane, isoflurane (volatile), propofol (IV), ketamine (IV), local anaesthetics (lignocaine/lidocaine, bupivacaine)	Variable — sevoflurane alone estimated at thousands of litres per year4	No
Cautery tips and pads	Diathermy pencils, grounding pads, bipolar forceps tips	Hundreds of thousands of units	No
Stapling devices	Skin staplers, internal surgical staplers and cartridges	Tens of thousands of units	No
Suction tubing and drains	Disposable suction tubing, wound drains, chest drains	Hundreds of thousands of units	No
Syringes and needles	Disposable syringes (all sizes), hypodermic needles	Millions of units	No
Antiseptics	Chlorhexidine, povidone-iodine (Betadine), alcohol-based surgical preps	Hundreds of thousands of units/litres	Some povidone-iodine may be packaged locally; active ingredients imported

1.2 In-country stock levels

Estimate: NZ’s hospital and distributor supply chain typically holds 1–6 months of surgical consumable supply, depending on the item. Common items (gloves, gauze, standard sutures) tend to have deeper buffers; specialised items (specific stapler cartridges, exotic suture materials, unusual sizes) may have only weeks of supply.⁵

Key NZ distributors:

• Medline/Mediray — major medical consumable distributors
• EBOS Group (Health division) — medical supplies and devices alongside pharmaceutical distribution⁶
• Surgical Specialties NZ, Device Technologies, and other specialist distributors for specific product lines
• Hospital-specific procurement — larger DHBs/Te Whatu Ora hospitals hold their own stocks

Assumption: These stock levels are commercial estimates and are not publicly reported at aggregate national level. The national inventory process (Doc #1, Doc #116 Section 7.1) must include surgical consumables alongside pharmaceuticals. The same urgency applies: NZ must know what it has.

1.3 Consumption under post-event conditions

Surgical volume will change in contradictory ways after the event:

Increased demand:

• Trauma from increased manual labour, reduced workplace safety infrastructure, wood-processing and agricultural injuries
• Delayed presentations — conditions that would have been treated early (appendicitis, hernias, fractures) present later and more severely when transport is difficult
• Infection complications requiring surgical drainage or debridement, particularly if antibiotic supply is constrained (Doc #116)

Decreased demand:

• Elective surgery (joint replacements, cosmetic procedures, many orthopaedic procedures) ceases or is drastically reduced
• Reduced road traffic means fewer motor vehicle trauma cases — one of the largest categories of acute surgical workload
• Population health changes — reduced obesity-related surgical need over time, though this takes years

Net estimate: Surgical volume probably drops by 30–60% overall (loss of elective caseload), but the remaining cases are more urgent and more complex on average. Consumable use per case may increase as resterilisation and improvisation add steps to each procedure. The net effect on consumable consumption is a reduction, but not as large as the reduction in case volume would suggest. Assumption: A 30–50% reduction in total surgical consumable consumption from pre-event baseline is a reasonable planning figure, but this is uncertain and depends heavily on how quickly local production of basic items (dressings, sutures) comes online.

---

2. EXTENDING EXISTING STOCKS

2.1 Resterilisation of single-use items

The most immediate opportunity is resterilisation and reuse of items currently designated “single-use” by their manufacturers. This designation is often driven by regulatory and commercial considerations rather than physical impossibility of reuse.⁷

The history: Before the disposable era (roughly pre-1970s), virtually all surgical instruments, drapes, gowns, and many other items were reused after sterilisation. Disposable items became standard because they eliminated reprocessing labour, reduced infection risk in settings with poor sterilisation infrastructure, and — critically — generated recurring revenue for manufacturers. The shift was not because reuse was inherently unsafe. It was because disposability was convenient and profitable.

Items that can be safely resterilised and reused:

Item	Reuse potential	Reprocessing method	Limitations
Surgical instruments (forceps, scissors, retractors, clamps)	Excellent — designed for reuse already	Autoclave (steam sterilisation)	Normal practice. Resharpening needed over time
Metal scalpel handles	Excellent	Autoclave	Blades need replacement; handles are permanent
Surgical drapes (reusable fabric type)	Excellent	Laundry + autoclave	Must switch from disposable to fabric drapes — see Section 4
Surgical gowns (reusable fabric type)	Excellent	Laundry + autoclave	Same as drapes
Metal suction tips (Yankauer, Poole)	Excellent	Autoclave after thorough cleaning	Verify lumen patency
Glass syringes	Excellent — standard pre-1960s	Autoclave	Must be carefully inspected for chips and cracks. Markings may fade
Tourniquets (rubber)	Good	Chemical disinfection (alcohol or chlorhexidine wipe) or autoclave if silicone	Rubber degrades with repeated autoclaving
Diathermy forceps (bipolar/monopolar)	Good	Autoclave; inspect insulation	Insulation degrades over time — must be tested before each use
Laryngoscope blades	Good	Autoclave or high-level chemical disinfection	Some have fibre-optic components that may not tolerate repeated autoclaving

Items where resterilisation is possible but requires careful protocols:

Item	Reuse potential	Concerns
Disposable scalpel blades	Limited — dulling is the main issue, not sterility. Can be autoclaved 2–5 times before discarding, with sharpening (Section 5.4)	Surgical performance degrades with dull blades — tissue damage, longer procedures
Single-use surgical staplers	Very limited — cartridge mechanisms deform. Skin staplers can sometimes be reloaded manually	Complex internal mechanisms are not designed for reuse
Disposable suction tubing	Limited (3–5 uses) — autoclaving degrades the plastic, causing it to stiffen and crack	Must be inspected after each cycle
Disposable syringes (plastic)	Limited (1–3 uses) — plastic degrades, markings fade, plunger seals lose integrity	Glass syringes are the long-term solution
Latex/nitrile surgical gloves	Possible but not recommended — integrity testing is impractical; microperforation rate increases with reuse8	Only in extremis. Ungloved surgery using rigorous hand antisepsis (see Section 2.3) is historically safer than surgery with compromised gloves

Items that cannot be meaningfully reused:

• Adhesive dressings (adhesive degrades)
• Suture material (structural integrity is the entire point — cannot be reused after cutting and handling)
• Absorbable haemostatic agents (Surgicel, Gelfoam)
• Wound closure strips (Steri-Strips)
• Single-use battery-operated devices

2.2 Rationing protocols for surgical consumables

Principle: Every disposable item used in surgery should be evaluated against the question: “Is there a reusable alternative that performs adequately?” If yes, switch to the reusable alternative immediately and reserve the disposable for situations where reuse is not feasible.

Immediate rationing measures (Day 1–30):

1. Cease all elective surgery that is not clinically time-sensitive. This is the single largest reduction in consumable use. Resume selectively once stock levels are known and local production is developing.
2. Inventory all surgical consumable stocks in every hospital, surgical centre, and distributor warehouse — same urgency as the pharmaceutical inventory (Doc #116).
3. Switch to reusable drapes and gowns where available. Most NZ hospitals still have some reusable linen packs in storage or can source them. If not available, begin production (Section 4).
4. Limit suture use to minimum effective quantities. Surgeons will need to adjust closure techniques — fewer interrupted sutures, more continuous closures, judicious use of staples where sutures are scarce and vice versa.
5. Restrict use of speciality items (specific stapler cartridges, exotic suture materials, single-use instruments) to cases where no alternative exists.
6. Centralise and redistribute stocks. If a rural hospital has 5 years of a speciality item that a tertiary centre needs monthly, transfer it. The national database enables this.

2.3 The glove question

Surgical gloves are a particular challenge. NZ does not manufacture latex or nitrile gloves, and the machinery to do so is specialised and not available in the country. Natural rubber latex requires tropical Hevea brasiliensis trees, which do not grow in NZ’s climate.

Options as glove supply depletes:

1. Strict conservation. Double-gloving (standard practice for high-risk cases) should be reduced to single-gloving for most procedures. Examination gloves can substitute for surgical gloves in lower-risk procedures (minor surgery, wound care). Gloves reserved for surgery; other clinical uses transition to rigorous hand hygiene.

2. Ungloved surgery with surgical hand antisepsis. This is how surgery was performed from the 1880s (when Lister’s antiseptic principles were adopted) until the 1890s–1900s (when Halsted introduced rubber surgical gloves). The technique — meticulous surgical scrubbing with antiseptic solution, careful operative technique to minimise hand-wound contact — was the standard of care for decades. Infection rates were higher than with gloves but far lower than without any antisepsis.⁹ This is the fallback when gloves are exhausted.

3. Improvised barrier methods. Intestinal membrane (from sheep — NZ has approximately 25 million sheep) was used historically as a surgical barrier material. This is labour-intensive to prepare but feasible (see Section 4.6).

Realistic trajectory: With strict conservation (single-gloving for surgery, no gloves for non-invasive procedures), glove stocks likely last 1–3 years. The basis: NZ holds approximately 5–10 million pairs per year under normal conditions;¹⁰ conservation measures targeting a 60–80% reduction in clinical glove use would extend a 6-month distributor stock to roughly 18–30 months. This estimate is highly sensitive to actual stock levels (which must be verified by national inventory) and to how strictly conservation protocols are enforced. Ungloved surgery with chemical antisepsis becomes standard for most procedures during Phase 2–3. This is a real regression in safety — surgical site infection rates will increase — but it is manageable with strict technique.

---

3. STERILISATION INFRASTRUCTURE

3.1 Why this is the critical enabler

Everything in this document depends on reliable sterilisation. Reuse of instruments, drapes, and gowns is safe only if sterilisation is effective. Local production of dressings and sutures requires sterilisation before use. If autoclaves fail and cannot be repaired, surgical capability collapses regardless of how many instruments or sutures exist.

3.2 Autoclave types in NZ hospitals

NZ hospitals use three main types of steam steriliser:¹¹

Prevacuum (B-type) autoclaves: The standard for hospital central sterile services departments (CSSDs). These use a vacuum pump to remove air from the chamber before injecting steam, ensuring penetration into porous loads (wrapped instrument packs, linen). Typical parameters: 134°C at 206 kPa (30 psi) for 3–4 minutes, or 121°C at 103 kPa (15 psi) for 15–20 minutes. All major NZ hospitals have one or more of these units.

Gravity displacement autoclaves (N-type): Simpler units that rely on steam displacing air downward (steam is lighter than air). Less effective for porous loads but adequate for unwrapped instruments and liquids. Common in smaller facilities, dental practices, and veterinary clinics.

Tabletop autoclaves (S-type): Small units in GP practices, dental surgeries, and minor procedure rooms. Limited capacity but widespread — there are probably several thousand across NZ.

3.3 Autoclave maintenance and repair

Critical components that fail and must be maintained:

Component	Failure mode	Consequence	Repair difficulty
Door gasket/seal	Perishes, cracks, loses elasticity	Steam leaks — cannot reach sterilising temperature/pressure	Low — gaskets can be fabricated from silicone or rubber sheeting. This is the most common failure and the easiest to fix
Pressure gauge	Drifts, becomes inaccurate	Cannot verify sterilising conditions reached	Low–moderate — can be cross-referenced with biological indicators. Gauge repair is within NZ instrumentation workshop capability
Safety valve	Fails to seat, corrosion	Over-pressure risk (dangerous) or inability to hold pressure	Moderate — valve springs and seats are standard engineering items. Must be tested regularly
Vacuum pump (prevacuum units)	Wear, seal failure, motor burnout	Cannot achieve prevacuum — revert to gravity displacement mode (less effective for porous loads)	Moderate — pump rebuilds are within NZ workshop capability. Spare parts may need fabrication
Heating elements	Burnout	Cannot heat chamber	Moderate — elements can be rewound or replaced. Requires nichrome wire (finite stock) or alternative heating (see below)
Control electronics	Component failure, board failure	Cycle cannot be controlled automatically	High for replacement of original boards. Workaround: revert to manual control (timer, thermometer, pressure gauge) — this is how autoclaves operated before electronic controllers
Chamber and piping	Corrosion, pinhole leaks	Steam loss, contamination	Moderate to high — welding repair is possible but requires skilled work. Severe corrosion may be irreparable
Steam traps	Blockage, failure	Condensate not removed — wet packs, failed sterilisation	Low to moderate — cleaning or replacement. Steam trap mechanisms are simple

The key maintenance insight: Modern autoclaves are fundamentally simple machines — a pressure vessel, a heat source, a pressure/temperature control system, and a door seal. The electronic controls are a convenience, not a necessity. An autoclave whose electronic controller has failed can be operated manually with a pressure gauge, a thermometer, a timer, and a trained operator. Hospitals should train CSSD staff in manual autoclave operation now, before electronic controllers fail.

3.4 Alternative sterilisation methods

When autoclaves are unavailable or under repair, alternative sterilisation methods maintain surgical capability:

Boiling water sterilisation (100°C, 20–30 minutes): Not true sterilisation — does not reliably kill bacterial spores — but provides high-level disinfection adequate for many surgical instruments in an emergency. This was standard practice into the early 20th century. Limitations: does not sterilise porous items (drapes, dressings); does not kill Clostridium spores reliably.¹²

Pressure cooker sterilisation: A domestic or commercial pressure cooker achieves 121°C at 103 kPa — the same conditions as a gravity displacement autoclave. A large pressure cooker (40–60 litre capacity, available in commercial catering supply in NZ) can sterilise wrapped instrument packs and small dressing packs.¹³ This is a genuine and effective fallback for small facilities and field surgery. Limitations: small capacity, manual operation, requires fuel.

Dry heat sterilisation (160–170°C for 1–2 hours): Effective for instruments, glass syringes, and metal items. Achieved in a standard laboratory oven or a well-controlled wood-fired oven. Not suitable for rubber, plastics, or fabrics. Takes much longer than steam sterilisation.¹⁴

Chemical sterilisation (glutaraldehyde, peracetic acid, ethylene oxide): Glutaraldehyde (2% Cidex) achieves high-level disinfection in 20–45 minutes and sterilisation in 10 hours of immersion. NZ hospital CSSDs stock glutaraldehyde for heat-sensitive items (endoscopes, some plastic devices). Supply is finite and imported. Ethylene oxide gas sterilisation is available at some larger NZ hospitals — requires specialised equipment and ethylene oxide supply, both finite.¹⁵

Ethanol-based disinfection (70–80% ethanol): Not a steriliser (does not kill spores) but an effective surface disinfectant for instruments and skin preparation. Ethanol can be produced locally from fermented grain or sugar (Doc #113 discusses sulfuric acid, relevant to ether production discussed in Section 6). This becomes the backbone of antisepsis once imported chlorhexidine and povidone-iodine are exhausted. Note that ethanol disinfection is substantially less effective against bacterial spores (e.g., Clostridium tetani, C. perfringens) and mycobacteria than steam sterilisation; items that can be autoclaved must be autoclaved rather than relying on ethanol alone.¹⁶

3.5 Biological indicators and sterilisation verification

How do you know sterilisation has actually worked?

Chemical indicators (autoclave tape, indicator strips) change colour when exposed to sterilising conditions. NZ holds finite stock of these. They confirm exposure to heat and steam but not necessarily sterilisation.

Biological indicators (BI — Geobacillus stearothermophilus spore strips or vials for steam sterilisation) are the gold standard. If the spores are killed, the cycle achieved sterilisation. NZ hospitals stock these and use them for routine autoclave qualification. Supply is finite.

When indicators are exhausted:

• Temperature and pressure monitoring — if the autoclave reaches 134°C and 206 kPa for the required time, sterilisation has occurred. This requires functioning gauges, which must be maintained and cross-calibrated.
• Bowie-Dick equivalent testing — the air removal test for prevacuum autoclaves can be performed using a stack of towels with a chemical indicator in the centre. If steam penetrates to the centre of the pack, air removal is adequate.
• Clinical observation — ultimately, the test of sterilisation adequacy is whether patients develop post-operative infections at rates consistent with effective sterilisation. This requires systematic surgical site infection surveillance, which NZ hospitals already perform and should continue.

3.6 Autoclave fuel and energy

Under the baseline scenario, NZ’s electrical grid continues operating (85%+ renewable). Hospital autoclaves are electrically heated and will continue to function as long as the grid holds. This is a significant advantage.

Contingency: If a hospital loses grid power, autoclaves can be converted to external steam supply. A wood-fired boiler producing steam at 103–206 kPa can supply an autoclave. The adaptation requires: a boiler capable of sustaining the required pressure (typically a fire-tube or water-tube boiler, not a domestic water heater), pipework to connect the boiler to the autoclave steam inlet, a pressure-reducing valve to regulate delivery pressure, and a trained operator who can manage boiler combustion and monitor steam pressure manually. This is within NZ engineering workshop capability but requires planning and installation before it is needed — not a field improvisation. NZ hospitals should identify backup steam supply options now. Some older NZ hospital buildings still have boiler rooms from the pre-electric era that could potentially be recommissioned.

Pressure cooker sterilisation requires only a heat source — gas, wood, or coal — and is the most resilient fallback for small-scale sterilisation.

---

4. LOCAL PRODUCTION OF DRESSINGS AND DRAPES

4.1 The historical baseline

Before the disposable era, all surgical dressings, drapes, and gowns were made from woven fabric — primarily cotton muslin and linen. They were laundered, inspected, folded, packaged, and steam-sterilised between uses. This system functioned effectively worldwide for over a century. The technical requirements are:

• Fabric: Tightly woven, absorbent, durable enough to withstand repeated laundering and autoclaving. Cotton muslin (thread count 120–140 per inch) was the standard.¹⁷
• Laundering: Hot water (above 70°C) with detergent, followed by thorough drying
• Packaging: Fabric packs wrapped in additional muslin or paper, sealed with autoclave tape
• Sterilisation: Standard autoclave cycle

4.2 NZ fiber sources for surgical textiles

NZ does not grow cotton. However, NZ has two fiber sources that can produce adequate surgical textiles:

Wool (from NZ’s approximately 25 million sheep):¹⁸

NZ wool is abundant and the processing infrastructure (shearing, scouring, carding, spinning) still exists, though concentrated in a few facilities. Wool is:

• Naturally antibacterial (lanolin) and moisture-wicking
• Can be woven into tight, absorbent fabrics
• Durable under repeated laundering
• Autoclavable (withstands 121°C steam; slight felting occurs but does not impair function for dressings)¹⁹

Limitation: Wool fibers are not as smooth as cotton. For wound-contact dressings, wool lint sheds into wounds. This can be mitigated by using a finely woven wool fabric as the outer absorbent layer with a harakeke or linen inner contact layer, or by using scoured and processed wool muslin.

Harakeke fiber / muka (Doc #100):

Harakeke fiber is strong, smooth, and naturally antibacterial. Finely processed muka produces a soft, lint-free textile suitable for wound-contact dressings. The fiber:

• Has been used in traditional Māori wound care (rongoā Māori) — poultices wrapped in harakeke leaf material²⁰
• Can be woven into fine cloth when processed to muka (stripped, scraped, washed)
• Is naturally resistant to microbial growth
• Withstands steam sterilisation

Limitation: Harakeke processing is labour-intensive. Muka extraction by hand is slow (see Doc #100). Mechanical processing increases throughput but the machinery must be built. For surgical textiles, fine muka cloth requires skilled weavers and takes significant time per metre.

Linen (from NZ flax — not to be confused with harakeke/NZ flax):

True linen comes from Linum usitatissimum (common flax), which is a different plant entirely from harakeke (Phormium tenax). Linen flax can be grown in NZ — it was grown commercially in Canterbury and Southland historically — but there is currently no significant production or processing infrastructure.²¹ Establishing linen production requires seed stock (may be available from NZ’s crop research institutions, e.g., Plant & Food Research), field cultivation, retting, scutching, and weaving infrastructure. This is a Phase 3–4 development, not an immediate solution.

4.3 Practical production plan

Phase 1 (Months 0–12): Reusable fabric from existing NZ textile stocks

NZ’s textile sector — however diminished — still includes:

• Wool scouring and processing (mainly Canterbury — Cavalier Bremworth, NZ Yarn, and others)
• Some weaving capacity (niche producers)
• Extensive stocks of existing fabric in retail, wholesale, and household stores

Immediate action: Requisition or purchase suitable fabric for conversion to surgical drapes, gowns, and dressings. Suitable materials include:

• Cotton bed sheeting (the most available and suitable — tightly woven, absorbent)
• Cotton muslin (if available from fabric retailers)
• Linen fabric (available in some retail and hospitality supply)
• Clean cotton towelling (for absorbent dressings)

Hospital laundry departments and CSSDs know how to process reusable surgical linen. This is existing institutional knowledge. The barrier is not technical — it is the decision to switch.

Phase 2 (Years 1–3): Wool-based surgical textiles

Commission NZ’s wool processing industry to produce surgical-grade fabric:

• Finely woven wool muslin for drapes and gowns
• Wool/harakeke blend fabrics for dressings (wool for absorption, harakeke for wound-contact smoothness)
• Wool wadding for absorbent dressing pads

Specification for surgical drapes: Tightly woven fabric, minimum 120 threads per inch, pre-shrunk (washed and autoclaved before first surgical use to ensure dimensional stability). Must be free of loose fibers that could contaminate the surgical field. Light-coloured (undyed or bleached) to show contamination.

Phase 3 (Years 3–7): Harakeke-based surgical textiles and established linen production

• Muka cloth production at scale for wound-contact dressings
• Linen flax cultivation and processing coming online (if seed stock secured in Phase 1)
• Blended fabrics optimised through clinical experience

4.4 Dressing types and local equivalents

Modern disposable dressing	Local equivalent	Materials	Production difficulty
Gauze swabs (4x4, various sizes)	Woven cotton or wool muslin squares, cut and hem-sealed, autoclaved in packs	Cotton sheeting, wool muslin	Low — cutting and packing
Combine dressings (absorbent pads)	Layered pad: wound-contact layer (fine muslin or muka cloth), absorbent core (wool wadding or cotton batting), outer layer (muslin)	Wool, cotton, harakeke	Low–moderate
Adhesive dressings (Band-Aid type)	Non-adhesive dressings secured with tape or bandage	As above, plus locally made tape (see below) or roller bandage	Low
Roller bandages (crepe, conforming)	Woven cotton or wool-blend strips, 50–100mm wide, rolled	Cotton or wool fabric	Low
Wound closure strips (Steri-Strips)	Fabric strips with locally made adhesive (rosin/pine resin-based), or sutures	Fabric, pine resin, ethanol	Moderate
Surgical tape	Fabric tape with rosin-based adhesive	Cotton ribbon, pine resin	Moderate
Abdominal packs (laparotomy sponges)	Large woven pads with radiopaque markers (use a small metal clip sewn into each pad as a count marker)	Wool or cotton fabric, small metal clips	Low–moderate

4.5 Adhesive tape production

Surgical tape — used to secure dressings, mark skin, and tape endotracheal tubes — is a consumable that seems trivial until it runs out. Local production is feasible:

Rosin-based adhesive tape:

1. Collect pine resin (rosin) — NZ has extensive Pinus radiata plantations (~1.7 million hectares).²² Resin can be tapped from living trees or collected from logging residue.
2. Dissolve rosin in ethanol or turpentine (turpentine is distilled from pine resin).
3. Apply to cotton ribbon and allow to dry partially (leaving a tacky surface).
4. Roll and store.

This produces a tape that is adequate for dressing fixation. Performance gap vs. modern surgical tape: Rosin-based tape adhesion degrades significantly at temperatures above 30°C or in high-humidity environments (operating theatres in summer), and it loses tack rapidly when wet — dressings near wound drainage sites will require more frequent re-taping. The rosin residue on skin is harder to remove than modern acrylic adhesive residue and may cause contact dermatitis in some patients. Critically, rosin-based tape has low hypoallergenic properties — some patients will react to pine resin. It is not suitable for securing endotracheal tubes or intravenous lines where adhesion failure has immediate clinical consequences. For those high-stakes applications, use linen ties or bandage rather than adhesive tape. This is essentially the same technology used in the first commercial adhesive tapes (Johnson & Johnson’s first surgical tape, 1886, used a rubber-rosin adhesive on cotton).²³

4.6 Intestinal membrane for surgical barriers

Sheep intestinal membrane (serous membrane / serosa) has historical use as a surgical barrier material — glove linings, wound coverings, and grafts. Preparation:

1. Clean sheep intestine thoroughly (remove mesenteric fat and contents)
2. Soak in weak alkaline solution (lye from wood ash) to remove mucosa
3. Stretch on a frame and dry
4. Cut to size
5. Sterilise (autoclave or chemical)

This produces a thin, translucent, moderately strong membrane that can serve as a wound covering or improvisational barrier. It is labour-intensive and has limited practical surgical application compared to properly produced textile dressings. Performance gap vs. latex/nitrile gloves: Intestinal membrane is more permeable than latex or nitrile; it does not provide equivalent barrier protection against bloodborne pathogens or bacterial contamination. Tensile strength is lower — tearing during a procedure is a real risk. It is also not reliably sterilisable by autoclave without degradation, and chemical sterilisation (ethanol immersion) may leave the membrane brittle. In practice, intestinal membrane is best used for wound coverage rather than as surgical gloves, and should not be relied upon as a primary surgical barrier where any alternative exists. Its primary value is in wound coverage for burns and large surface wounds where textile dressings would adhere to the wound bed.

---

5. LOCAL SUTURE PRODUCTION

5.1 Why sutures matter

Sutures are among the most critical surgical consumables because they have no workaround — a wound that needs closure needs closure. You cannot operate without the ability to close what you open. NZ uses approximately 500,000–800,000 suture packets per year under normal conditions. Even with drastically reduced surgical volume, suture supply is a binding constraint on surgical capability.

5.2 Catgut sutures from sheep intestine

Phase: 1–3 (pilot production Months 3–12; scale-up Years 1–5) | Feasibility: [A] Established — process is well-documented historical practice; NZ raw material supply is abundant

Catgut is not made from cats. The name is a corruption of “kitgut” or “cattlegut” — it is made from the submucosa of sheep, goat, or cattle intestine. It was the standard absorbable suture material from the 19th century until the introduction of synthetic absorbables (polyglactin, polyglycolic acid) in the 1970s.²⁴

NZ’s advantage: NZ has approximately 25 million sheep.²⁵ The raw material for catgut suture production is a byproduct of the meat processing industry. NZ meat processing plants (Silver Fern Farms, Alliance Group, ANZCO Foods, and others) process millions of sheep per year. Intestines are currently a low-value byproduct — some exported for sausage casings, some rendered, some discarded. Under recovery conditions, sheep intestine becomes a strategic surgical supply.

Production process:

1. Harvest: Collect small intestine from freshly slaughtered sheep. The intestine should be processed within hours of slaughter to prevent bacterial degradation. Length per sheep: approximately 20–25 metres of small intestine.²⁶

2. Cleaning: Slit the intestine lengthwise. Remove mesenteric fat and connective tissue. Wash thoroughly in clean water.

3. Stripping: Scrape the intestine to isolate the submucosa — the tough, collagen-rich middle layer. This is done by mechanical scraping or by soaking in dilute alkali (sodium hydroxide solution, approximately 0.1–0.5%) followed by scraping. The mucosa (inner lining) and serosa (outer membrane) are removed, leaving a translucent ribbon of submucosa.²⁷

4. Splitting: Cut the submucosa ribbon into strips of appropriate width. The width determines the final suture gauge. For a suture equivalent to modern 2-0 or 3-0 (the most commonly used sizes), strips approximately 3–5 mm wide are appropriate.

5. Twisting: Twist 2–4 strips together under tension to form a cord. The number of strips and tightness of twist determine the final strength and gauge. Twisting is done wet; the suture is then dried under tension.

6. Polishing: After drying, the suture is polished by drawing through a lightly abrasive surface (fine pumice or leather) to smooth the surface and reduce tissue drag.

7. Chromic treatment (optional but recommended): Treating catgut with chromic salt solution (chromium trioxide or potassium dichromate, approximately 2–5% solution) cross-links the collagen, increasing its tensile strength and extending its absorption time in tissue from approximately 10 days (plain gut) to 20–40 days (chromic gut).²⁸ Chromium salts are imported and finite. NZ holds stock in leather tanning operations and chemical supply. This stock should be identified and reserved for surgical catgut production.

8. Sterilisation: Historically, catgut was sterilised by immersion in chemical solutions (iodine-alcohol, or cumol/isopropyltoluene). Autoclaving catgut degrades its tensile strength and is not recommended. Gamma radiation sterilisation (used for modern commercial catgut) is not available. Chemical sterilisation options:

   • Iodine-alcohol solution (2% iodine in 70% ethanol) — immersion for 7 days²⁹
   • Ethanol (70–80%) — immersion for extended period (weeks)
   • Ethylene oxide gas — if available (finite NZ stock)

9. Packaging: Coil sterilised suture in individual packets, stored in sterilising solution until use. Historically, catgut sutures were stored in glass tubes containing alcohol or iodine solution.

Needle attachment: Modern sutures come swaged (permanently attached) to needles. Catgut sutures historically were threaded through eyed surgical needles — the same approach used for sewing, on a smaller scale. Eyed surgical needles are reusable and are included in standard surgical instrument sets. They create a slightly larger tissue hole than swaged sutures (the eye is wider than the suture strand), which increases tissue trauma marginally. This is a real but minor disadvantage.

Quality and performance compared to modern sutures:

Property	Catgut	Modern synthetic absorbable (e.g., polyglactin/Vicryl)
Tensile strength	Moderate — adequate for most wound closures; unreliable for high-tension closures (fascia)	High and predictable
Absorption time	Variable — plain 7–10 days; chromic 20–40 days	Predictable — Vicryl ~60–90 days
Tissue reaction	Moderate–high inflammatory reaction (it is animal protein)	Low
Handling characteristics	Stiff when dry, softens when wet. Harder to handle than modern sutures	Smooth, consistent, easy to handle
Knot security	Good — requires more throws than synthetic (4–5 square throws recommended)	Excellent
Infection risk	Higher if sterilisation is inadequate	Factory-sterilised — minimal
Consistency between lots	Variable — depends on production quality	Extremely consistent

Summary: Catgut is a genuine, functional suture material that served surgery well for over a century. It is inferior to modern synthetic sutures in every measurable dimension — but the gap is manageable. Surgeons trained on modern sutures will need to adapt their technique. The main risks are inconsistent tensile strength (mitigated by testing each production lot) and infection from inadequate sterilisation (mitigated by strict protocols).

5.3 Silk sutures

Phase: 3–4 for domestic production (Years 3–10+); Phase 1–2 for existing stock use | Feasibility: [C] Precursor industry required — sericulture does not exist in NZ; mulberry cultivation and silk-reeling must be established before domestic production is possible

Silk is the strongest natural fiber available for suture manufacture. Silk sutures — braided from multiple fine silk filaments — were the standard non-absorbable suture material from the early 20th century until synthetic non-absorbables (nylon, polypropylene) became available in the 1950s–60s.³⁰

Can NZ produce silk?

NZ does not currently have a sericulture (silk production) industry. Silkworms (Bombyx mori) feed on mulberry leaves (Morus species). Mulberry trees grow in NZ — they are present as ornamental and fruit trees, particularly in northern NZ — but there is no established plantation or silk-reeling infrastructure.³¹

Feasibility assessment: Establishing sericulture in NZ is a Phase 3–4 project requiring:

• Sourcing silkworm eggs (available from hobbyist suppliers in NZ/Australia, or possibly from NZ entomological collections)
• Mulberry tree cultivation (trees take 3–5 years to reach productive size from seedling; existing trees could be harvested earlier)³²
• Silk reeling (unwinding cocoons, a specialised skill but well-documented)
• Suture braiding (twisting multiple filaments into suture thread)

Short-term silk source: NZ may hold stock of raw silk thread in textile supply, craft supply, and fashion industry channels. This stock should be identified and reserved for surgical use if suture production is needed before a sericulture industry develops.

Silk suture properties:

• Non-absorbable (remains in tissue permanently unless removed)
• Excellent handling characteristics — surgeons consistently prefer silk’s feel over other suture materials
• Good knot security
• Moderate tissue reaction (higher than nylon or polypropylene, lower than catgut)
• Can be sterilised by autoclaving (unlike catgut)

5.4 Surgical needle and instrument maintenance

Sutures are useless without needles, and needles are useless if dull. Maintaining the sharpness and integrity of surgical instruments is a critical skill under conditions where replacements are unavailable.

Needle sharpening:

Surgical needles (both eyed needles for hand-threading and the needles on swaged sutures, if carefully removed and reused) can be sharpened using:

• Fine Arkansas stone or ceramic hone — available in NZ from tool supply. The needle is drawn along the stone under magnification (loupe or microscope) to restore the cutting edges
• Stropping — drawing the needle across leather dressed with fine abrasive compound (jeweler’s rouge / iron oxide)
• Inspection under magnification — a needle that has lost its point or developed a hook (bent tip) must be resharpened or discarded. A hooked needle tears tissue rather than cutting it

Scalpel blade sharpening:

Disposable scalpel blades (carbon steel or stainless steel) can be resharpened 2–5 times before the blade geometry degrades beyond usefulness:

• Use a fine-grit sharpening stone (1000+ grit)
• Maintain the original bevel angle (approximately 15–20 degrees for most surgical blades)
• Strop on leather for final edge
• Inspect under magnification — the edge should be smooth and continuous, without chips or irregularities
• Sterilise after sharpening

Instrument resharpening and repair:

Instrument	Maintenance need	Method
Scissors (Metzenbaum, Mayo)	Resharpening cutting edges	Dismount (if possible), sharpen each blade on a fine stone, reassemble and test cut on silk thread
Forceps (toothed, non-toothed)	Realignment of tips, tightening of spring	Alignment jig, gentle bending under magnification
Needle holders	Replacing carbide inserts (if available), resharpening jaws	Jaw retexturing with fine diamond file
Retractors	Usually no sharpening needed — bending and straightening	Metal-working
Rongeurs (bone-biters)	Resharpening cutting edges	Fine stone, test on a splint or sample bone
Osteotomes and chisels	Resharpening	Standard chisel sharpening technique on oilstone
Curettes	Resharpening cutting edge	Fine round file or stone

A dedicated surgical instrument maintenance workshop should be established at each major hospital or regional centre. This requires: fine sharpening stones, magnifying equipment (loupes at minimum; a stereo microscope is ideal), fine files, alignment jigs, and a trained technician. This role exists already in some NZ hospitals (instrument technicians in CSSDs) and should be formalised and expanded.

---

6. ANAESTHETIC AGENTS

6.1 The problem

Modern anaesthesia depends on imported agents — primarily volatile anaesthetics (sevoflurane, isoflurane, desflurane) for general anaesthesia and synthetic local anaesthetics (lignocaine/lidocaine, bupivacaine) for regional and local anaesthesia. NZ does not manufacture any of these.

Stock estimates:³³

Agent	Estimated NZ stock	Rate of depletion (post-event)	Approximate duration
Sevoflurane	Hundreds to low thousands of litres across hospitals and distributors	Reduced by ~50% with reduced surgical volume and conservation measures	1–3 years (estimate)
Isoflurane	Smaller stocks — largely displaced by sevoflurane in NZ practice	Same as sevoflurane	Months to 1–2 years
Propofol	Moderate stocks — emulsion, finite shelf life (months to 1–2 years after labelled expiry)	Used for induction; can be replaced by other agents	1–2 years
Ketamine	Moderate stocks in hospitals and veterinary supply	Low consumption rate; long shelf life as solid or concentrated solution	2–5+ years
Lidocaine (lignocaine)	Moderate to substantial stocks — widely used, widely stocked	Used for local anaesthesia, regional blocks, and as an antiarrhythmic	1–3 years
Bupivacaine	Smaller stocks than lidocaine	Used for spinal and epidural anaesthesia	1–2 years
Thiopentone (thiopental)	Small stocks — largely superseded by propofol	IV induction agent	1–6 months (estimate; low pre-event stocking levels)
Suxamethonium (succinylcholine)	Small stocks — requires cold storage (2–8°C); cold chain loss accelerates degradation	Muscle relaxant for rapid intubation	1–12 months depending on cold chain integrity
Other muscle relaxants (rocuronium, atracurium)	Small to moderate stocks	Required for paralysis during surgery	1–2 years

6.2 Conservation strategies

Shift toward regional and local anaesthesia: The single most effective conservation strategy is performing as many operations as possible under local or regional anaesthesia instead of general anaesthesia. This eliminates the need for volatile agents, propofol, and muscle relaxants for those cases.

• Spinal anaesthesia (intrathecal injection of local anaesthetic) provides complete anaesthesia below the umbilicus. Adequate for caesarean sections, lower limb surgery, hernia repair, appendicectomy, and many urological procedures. Requires small volumes of local anaesthetic (1–3 mL of bupivacaine or equivalent). Extends local anaesthetic stock enormously compared to field block or infiltration.
• Epidural anaesthesia — similar applications, larger local anaesthetic volume but provides ongoing pain relief.
• Nerve blocks (brachial plexus, femoral, sciatic, intercostal) — provide anaesthesia for limb surgery. Requires moderate volumes of local anaesthetic. Ultrasound-guided blocks (Doc #116 — imaging equipment operational while grid is up) improve success rates.
• Local infiltration — adequate for minor surgery, wound exploration, laceration repair. Requires smallest volumes per case.

Low-flow and closed-circuit anaesthesia: For general anaesthesia cases, vapour conservation through low-flow breathing circuit technique reduces sevoflurane/isoflurane consumption by 50–75% compared to standard semi-open circuits. Most modern NZ anaesthetic machines support low-flow technique. Anaesthetists should be trained and required to use low-flow circuits.³⁴

Ketamine anaesthesia: Ketamine is a uniquely valuable agent in the recovery context because:

• It provides anaesthesia, analgesia, and amnesia from a single drug
• It can be given intravenously, intramuscularly, or orally
• It does not require an anaesthetic machine or breathing circuit (patients maintain their own airway in most cases)
• It has a wide safety margin
• It is stable (long shelf life, no cold chain required)
• NZ has both human and veterinary stocks (ketamine is widely used in veterinary anaesthesia)

Limitation: Ketamine produces unpleasant emergence phenomena (hallucinations, agitation) in some patients, mitigated by co-administration of a benzodiazepine (diazepam or midazolam). It raises intracranial pressure (contraindicated in head injury) and raises blood pressure (caution in hypertension). It is a controlled substance with abuse potential. Despite these limitations, ketamine becomes NZ’s most important anaesthetic agent once volatile agent supplies are exhausted.³⁵

6.3 Diethyl ether — the local production option

Phase: 2–3 (Years 1–7) | Feasibility: [B] Buildable — chemistry is established; depends on sulfuric acid production capability (see Section 6.3 dependency note and Doc #113)

Diethyl ether (“ether”) was the first widely used general anaesthetic (introduced 1846) and remained in common use globally until the 1960s–70s, when it was displaced by halothane and then by the modern volatile agents.³⁶ It is still used in some developing countries where modern agents are unavailable. It can be produced locally from materials available in NZ, but production depends on sulfuric acid availability — a Phase 2 industrial chemistry project that is not guaranteed within any fixed timeline.

Properties relevant to recovery-era use:

Property	Value / Assessment
Anaesthetic potency	Moderate — MAC (minimum alveolar concentration) approximately 1.9% in adults.37 Requires relatively high concentrations compared to modern volatile agents (sevoflurane MAC approximately 2.05%, isoflurane approximately 1.15%)
Safety margin	Wide — the difference between anaesthetic dose and lethal dose is larger than for modern agents. This is a significant advantage in field conditions
Analgesia	Provides substantial analgesia (unlike sevoflurane/isoflurane) — reduces need for supplemental analgesics
Respiratory effects	Maintains spontaneous respiration better than modern agents at clinical doses
Cardiovascular effects	Relatively stable — less cardiovascular depression than modern agents
Nausea/vomiting	High — ether produces significantly more postoperative nausea and vomiting than modern agents
Induction/recovery	Slow — induction takes 10–15 minutes (vs. seconds for IV propofol). Recovery is prolonged (30–60+ minutes)
Flammability	Highly flammable. This is the primary safety concern. Ether vapour is denser than air and accumulates near the floor. NO electrocautery or diathermy can be used while ether is being administered. Open flames must be excluded from the operating room.38
Storage	Volatile — must be stored in sealed dark containers. Peroxide formation on exposure to air and light is a degradation and safety hazard

Production of diethyl ether:

Diethyl ether is produced by the acid-catalysed dehydration of ethanol:

2 CH₃CH₂OH → CH₃CH₂OCH₂CH₃ + H₂O (with sulfuric acid catalyst, at 130–140°C)

Requirements:

1. Ethanol — NZ can produce ethanol by fermentation and distillation from any sugar-containing or starch-containing feedstock: grain, sugar beet, potatoes, fruit waste. NZ’s existing distilling industry (whisky distillers, Manuka honey mead producers, and the bioethanol sector) provides both equipment and knowledge. Ethanol must be concentrated (95%+ by distillation, ideally dried further for ether synthesis) but does not need to be absolute.³⁹

2. Sulfuric acid — the catalyst. NZ does not currently manufacture sulfuric acid at scale, though small quantities are held by industrial users and laboratories. Sulfuric acid can be produced from elemental sulfur (available from NZ geothermal areas — Rotorua, Taupo volcanic zone) or from iron pyrite (present in some NZ mineral deposits) by the contact process or lead chamber process. This is a significant industrial chemistry project but feasible within NZ’s capability (see sulfuric acid dependency note below).⁴⁰ Sulfuric acid is not consumed in the ether synthesis — it acts as a catalyst and is recoverable.

3. Glassware or reaction vessel — the synthesis can be performed in standard laboratory glassware (round-bottom flask with thermometer, condenser, and collection vessel) or in a larger-scale metal reaction vessel lined with lead or glass (sulfuric acid corrodes most metals).

4. Heat source — controlled heat to maintain the reaction at 130–140°C.

5. Purification — the crude ether product is washed with water (to remove alcohol and acid), then with sodium hydroxide solution (to neutralise residual acid), then with water again. It is dried over calcium chloride or sodium sulfate and redistilled. The final product should be clear, colourless, and have a characteristic sweet smell.

6. Stabilisation — ether forms explosive peroxides on exposure to air and light. Stabilisers (typically small amounts of butylated hydroxytoluene/BHT, or copper wire in the storage container) inhibit peroxide formation. Storage in dark, full (minimal headspace), sealed containers, preferably with a small amount of copper wire, extends shelf life.⁴¹

Production scale required: A single surgical operation using ether general anaesthesia consumes approximately 50–200 mL of liquid ether, depending on duration and technique.⁴² If NZ performs 100–300 general anaesthetics per year using ether (after maximising regional/local anaesthesia and ketamine), annual ether consumption would be approximately 5–60 litres (lower bound: 100 cases × 50 mL = 5,000 mL = 5 L; upper bound: 300 cases × 200 mL = 60,000 mL = 60 L). This is a very small-scale chemical production — well within laboratory or small-workshop capability.

Sulfuric acid dependency: Ether production depends on sulfuric acid availability. If NZ cannot produce sulfuric acid (Section 6.3, step 2 above), the ether synthesis cannot proceed. However, sulfuric acid has many other critical uses (fertiliser production, chemical manufacturing, battery acid) and its local production is likely to be one of the first industrial chemistry priorities regardless of the anaesthetic application. NZ’s geothermal sulfur deposits make this feasible. See the broader chemical production planning in the library’s industrial chemistry documents.

Ether administration equipment:

Modern vaporisers (calibrated devices on anaesthetic machines that deliver precise concentrations of volatile agents) are designed for sevoflurane, isoflurane, or desflurane — not ether. Ether has different physical properties (lower boiling point, different vapour pressure curve) and must be administered differently:

• Drawover vaporiser: A simple device where the patient’s inspiratory airflow passes over a wick or gauze saturated with liquid ether. The concentration depends on flow rate, temperature, and wick surface area. The EMO (Epstein-Macintosh-Oxford) drawover vaporiser was designed specifically for ether use in field conditions and was standard equipment in military and developing-world anaesthesia into the 1990s.⁴³ NZ does not currently have EMO vaporisers in clinical stock. Fabrication requires: machined aluminium or brass body components (lathe and milling machine work), a temperature-compensating bimetallic valve (requires precision metal fabrication and calibration), a wick chamber with appropriate wick material (fibreglass or natural fibre), inlet and outlet valves (standard engineering components), and clinical calibration against a known ether concentration reference. Published design specifications are available and the device is within the capability of a well-equipped NZ machine shop (Doc #91 — Machine Shop Operations), but the temperature-compensation mechanism is the critical precision component — fabricating it to perform adequately requires engineering skill and test equipment. Allow 2–4 weeks of skilled machine shop time per unit, plus calibration.
• Open-drop technique: The oldest method — liquid ether dripped onto a gauze mask (Schimmelbusch mask) placed over the patient’s face. Crude but functional. Concentration control is poor. Wastes ether through evaporation. Exposes operating room staff to ether vapour. Acceptable in extremis but a proper vaporiser is strongly preferred.⁴⁴
• Closed-circuit technique: A purpose-built or adapted anaesthetic circuit with a soda-lime carbon dioxide absorber can be used to administer ether with much less vapour waste. This requires an airtight circuit with a reservoir bag and one-way valves — components present in standard anaesthetic machines, though adaptation is needed.

6.4 Local anaesthetic alternatives

When lidocaine and bupivacaine are exhausted, options for local anaesthesia are limited but not zero:

Cocaine: The original local anaesthetic (used clinically from 1884). Can be extracted from coca leaves, which do not grow in NZ. Not a viable local production option.

Ethyl chloride spray: Produces brief surface anaesthesia by evaporative cooling. Can be synthesised (from ethanol and hydrochloric acid with zinc chloride catalyst), but the anaesthesia is too brief and superficial for surgical use. Useful only for minor procedures (incision and drainage of superficial abscesses).

Cold anaesthesia (cryoanaesthesia): Application of ice or cold packs to numb tissue before minor procedures. Limited to surface anaesthesia. Not adequate for anything beyond the most superficial incisions.

Ethanol injection: Direct injection of ethanol (50–95%) into or around nerves produces chemical neurolysis — permanent nerve destruction. Used historically for chronic pain and in some developing-world settings for amputation anaesthesia. This is a destructive procedure (it kills the nerve) and is only appropriate for amputations, terminal pain, or situations where no other anaesthesia is available.⁴⁵

Realistic assessment: There is no locally producible substitute that provides the same quality of local anaesthesia as lidocaine or bupivacaine. When synthetic local anaesthetic stocks are exhausted, local and regional anaesthesia capability degrades significantly. The workaround is general anaesthesia (ether or ketamine) for procedures that would normally be done under local — this uses more resources per case but maintains surgical capability.

---

7. ANTISEPTICS AND SKIN PREPARATION

7.1 Current NZ practice

NZ surgical teams use imported antiseptic products for surgical site preparation:

• Chlorhexidine gluconate (0.5–2% in alcohol or aqueous solution) — the current gold standard for surgical skin preparation⁴⁶
• Povidone-iodine (Betadine, 10% solution) — widely used, both for skin preparation and wound irrigation
• Alcohol (70% isopropanol or ethanol) — used in combination with chlorhexidine or alone

All of these are imported. Chlorhexidine and povidone-iodine are synthetic chemical products that NZ cannot manufacture without significant industrial chemistry infrastructure.

7.2 Locally producible antiseptics

Ethanol (70–80% solution):

This is the most important locally producible antiseptic. Ethanol at 70–80% concentration is an effective broad-spectrum antimicrobial agent that kills most bacteria, viruses, and fungi on contact. It is less effective against bacterial spores than chlorhexidine or iodine, but adequate for surgical hand antisepsis and skin preparation when combined with proper technique.⁴⁷

Production: Fermentation of any sugar or starch source, followed by distillation to 95%+ concentration, then dilution to 70–80% with clean water. NZ has distilling capability (Section 6.3). Ethanol production for antiseptic use should be a priority alongside ether production — the same feedstock and distillation infrastructure serves both.

Quantity required: Surgical hand scrubbing consumes approximately 50–100 mL of antiseptic per scrub. With two surgeons and a scrub nurse per case, that is 150–300 mL per operation. Skin preparation consumes another 50–100 mL. Total antiseptic per case: approximately 200–400 mL. At reduced surgical volumes (estimated 60,000–120,000 cases per year in Phases 1–3), NZ would need approximately 12,000–48,000 litres of antiseptic-grade ethanol per year for surgical use alone. Additional requirements for ward wound care, instrument surface disinfection, and non-surgical clinical use could easily double this figure. This requires a meaningful industrial-scale distillation operation — not a small still — and should be planned as a production programme from the earliest stages. At NZ’s pre-event craft and industrial distilling capacity, 15,000–50,000 litres per year is achievable but requires coordinated direction of ethanol production to medical-grade use.

Iodine tincture (2% iodine in 50% ethanol):

Iodine is a more effective antiseptic than ethanol alone, particularly against bacterial spores. NZ does not mine iodine, but:

• Existing stocks: Povidone-iodine (Betadine) and iodine tincture are stocked in hospitals, pharmacies, and veterinary supply. These are finite.
• Seaweed extraction (Phase: 2–3; Feasibility: [B] Buildable — NZ kelp is abundant; process is established chemistry but requires acid or chlorine availability and significant processing labour): Iodine can be extracted from kelp (brown seaweed), which grows abundantly along NZ’s coastline. The process — harvesting kelp, burning it to ash, leaching the ash with water, and precipitating iodine by adding sulfuric acid or chlorine — was the original industrial source of iodine (discovered 1811, commercialised from seaweed in the early 19th century).⁴⁸ NZ’s kelp species (Macrocystis pyrifera and Durvillaea species) contain approximately 0.1–0.5% iodine by dry weight; yield from the seaweed-to-iodine process is low, requiring approximately 200–1,000 kg of dried kelp per kilogram of extracted iodine depending on species and season. At NZ’s coastal kelp abundance, this is a feasible but labour-intensive operation requiring large-scale kelp harvesting, drying, and burning infrastructure. The process depends on either sulfuric acid (for iodine precipitation) or chlorine gas production — both Phase 2 chemical infrastructure dependencies.

Soap:

Soap for surgical hand preparation can be produced locally. Soap is made by saponification of fats or oils with alkali. The process is technically well-understood but requires some care: the lye concentration must be matched to the fat used (under-alkalised soap is greasy and ineffective; over-alkalised soap burns skin), and cure time is typically 4–6 weeks for bar soap. The dependency chain is: tallow (from slaughterhouse byproduct) + lye (from wood ash leachate or electrolytic sodium hydroxide) + controlled saponification (heat, mixing) + cure time.

• Fat source: Tallow from NZ’s sheep and cattle (abundant)
• Alkali source: Sodium hydroxide (lye) from wood ash leachate or from electrolysis of salt solution (NZ has sea salt). Potassium hydroxide from wood ash produces soft (liquid) soap; sodium hydroxide produces bar soap. Wood ash leachate produces potassium hydroxide at variable and hard-to-measure concentrations — the lye strength must be tested (traditionally with a potato or egg: the object floats when concentration is adequate) before use.
• Process: Heat fat to liquid (approximately 60°C), add lye solution slowly while stirring, continue until saponification is complete (mixture reaches “trace” — a pudding-like consistency), pour into moulds, cure 4–6 weeks before use. NZ craft soap producers are familiar with this process and represent a training resource.

Hypochlorite (bleach):

Sodium hypochlorite (household bleach) is an effective disinfectant for surfaces, instruments (as a soak), and wound irrigation (at low concentration — Dakin’s solution, approximately 0.025–0.05% sodium hypochlorite). It can be produced by:

• Electrolysis of salt water (NaCl → NaOCl + H₂) — requires electric power and salt, both available in NZ
• Passing chlorine gas through sodium hydroxide solution — requires chlorine production, which requires electrolysis of brine

NZ’s continued electrical grid availability makes electrolytic hypochlorite production feasible. Small-scale hypochlorite generators (used for water treatment) exist in NZ.⁴⁹ The process requires: a DC power source (12–24 V), inert electrodes (titanium with mixed metal oxide coating, or platinum — standard components in NZ water treatment equipment), salt (NaCl) dissolved in water at approximately 25–30 g/L, and a containment vessel. Concentration of the output hypochlorite solution is approximately 0.5–1.5% (5,000–15,000 ppm available chlorine), which is then diluted further for antiseptic use. The main technical challenge is maintaining electrode integrity over time — electrode consumption limits the lifespan of improvised units. Replacement electrodes may need to be sourced from NZ water treatment suppliers.

Dakin’s solution for wound irrigation:

Developed during World War I by Henry Dakin and Alexis Carrel, Dakin’s solution (dilute sodium hypochlorite, approximately 0.025–0.05%, buffered with boric acid to reduce tissue toxicity) was the standard wound irrigation and antiseptic solution for decades. It is effective against a broad range of bacteria and can be produced from locally available materials (bleach diluted with clean water, buffered with boric acid if available).⁵⁰

7.3 Surgical hand preparation without modern antiseptics

When chlorhexidine scrub is exhausted, the surgical hand preparation sequence becomes:

1. Wash hands and forearms with soap and clean water (2–3 minutes, using a scrub brush for nails and skin folds)
2. Rinse thoroughly
3. Apply 70–80% ethanol to hands and forearms, rubbing until dry (2–3 minutes)
4. Don sterile gloves (while glove supply lasts) or proceed directly to surgery with clean, antiseptic-prepared hands

This is essentially the technique used from the late 19th century through the mid-20th century. It is effective. The critical variables are thoroughness of washing, concentration and contact time of ethanol, and avoidance of recontamination before and during the procedure.

---

8. WHAT SURGERY LOOKS LIKE: YEAR 1 VS. YEAR 5

8.1 Year 1 — Modern resources, conservation mindset

In Year 1, most surgical infrastructure and consumable stocks remain available. The changes are primarily organisational:

What stays the same:

• Operating theatres functional (lighting, suction, monitoring equipment, anaesthetic machines all operational)
• Modern instruments, sutures, and drapes still available from existing stocks
• Modern anaesthetic agents (sevoflurane, propofol, muscle relaxants) still in supply
• Diagnostic capability intact (X-ray, ultrasound, CT if available, laboratory services)
• Trained surgical, anaesthetic, and nursing workforce in place

What changes:

• Elective surgery drastically reduced or suspended
• Conservation protocols in effect: low-flow anaesthesia, minimised suture use, reduced disposable consumption
• Reusable drapes and gowns phased in alongside remaining disposable stocks
• National inventory of all surgical consumables underway
• Local production of dressings, catgut sutures, and antiseptics beginning as development projects (not yet needed for clinical use)
• Surgical instrument maintenance programme formalised
• Training in ether anaesthesia, regional anaesthesia techniques, and ungloved surgery technique begins (prophylactic skill development — not yet clinically necessary)

Surgical capability: Approximately 80–90% of pre-event capability for the cases that are still performed (estimate; the main loss is volume from elective surgery suspension, not technical quality — modern instruments, anaesthetics, and consumables remain available). This estimate is uncertain: it assumes no significant disruption to hospital power, staffing, or supply chains beyond the suspension of elective surgery.

8.2 Year 3 — The transition

By Year 3, some consumable categories are exhausted or severely depleted. The transition to local alternatives is underway:

Likely exhausted or nearly so:

• Surgical gloves (or severely rationed)
• Some suture types (speciality synthetic sutures; common sizes may still have stock)
• Volatile anaesthetic agents (sevoflurane likely exhausted; isoflurane stocks very low)
• Chlorhexidine and povidone-iodine stocks heavily depleted
• Disposable drapes, gowns, and many single-use items exhausted
• Propofol exhausted
• Surgical staplers and cartridges exhausted or rationed to essential use only

Available:

• Reusable fabric drapes and gowns (wool/cotton, locally produced)
• Locally produced wound dressings (not yet at ideal quality, but functional)
• Catgut suture production established (at least in pilot production at one or two centres)
• Ether production underway (small scale, adequate for limited use)
• Ketamine stocks still available (stable, long shelf life, supplemented from veterinary supply)
• Ethanol-based antiseptics in production
• Lidocaine/bupivacaine stocks depleted but not yet exhausted (regional anaesthesia used strategically)
• All reusable instruments maintained and functional
• Autoclaves maintained and operational

Surgical capability: Approximately 50–70% of Year 1 capability (estimate; upper end assumes catgut and ether production both come online within the timeline described; lower end assumes delays in sulfuric acid or catgut production, more rapid glove exhaustion, or partial autoclave failures). The range of operations is narrower (anything requiring electrocautery cannot be done simultaneously with ether anaesthesia; complex reconstructive surgery limited by suture variety; long operations more difficult with ether’s slow induction and recovery). Infection rates are rising modestly as glove supply depletes and antiseptic variety narrows. But life-saving surgery — caesarean sections, appendicectomy, hernia repair, fracture fixation, drainage of abscesses, debridement of wounds — continues.

8.3 Year 5 — The new normal

By Year 5, the transition to sustainable surgical practice is largely complete:

Standard surgical consumables:

• Catgut sutures (plain and chromic) — locally produced, routinely available
• Silk sutures — from existing stock or early sericulture production, if established
• Woven fabric drapes and gowns — wool and/or harakeke, laundered and autoclaved
• Locally produced dressings — wool/harakeke/cotton blend, autoclaved packs
• Ethanol-based hand antisepsis — routine
• Iodine tincture (from seaweed extraction) — available but limited
• Soap — locally produced
• Eyed surgical needles — reused, resharpened

Anaesthesia:

• Ether — available for general anaesthesia (drawover vaporiser or adapted circuit)
• Ketamine — if stocks remain; production from scratch is not feasible in NZ
• Spinal and regional anaesthesia — routine for appropriate cases, using any remaining local anaesthetic stock. When local anaesthetics are exhausted, general anaesthesia is required for all surgical procedures
• No electrocautery during ether cases — haemostasis by ligation, pressure, and suture

Instruments:

• Pre-event instruments maintained through resharpening and repair
• Some instruments fabricated locally (retractors, simple forceps, scalpel handles) from NZ steel (Doc #91)
• Autoclave sterilisation — operational with manual controls where electronic controllers have failed

What this looks like in practice:

A typical surgical case in Year 5 — say, an appendicectomy for acute appendicitis:

1. Patient assessed in a functioning emergency department (electric lighting, diagnostic capability from physical examination and possibly ultrasound if equipment still operational)
2. Decision to operate made by surgeon
3. Patient prepared: skin shaved and cleaned with soap and water, followed by ethanol-iodine solution
4. Anaesthesia: spinal anaesthetic if local anaesthetic still available; otherwise ether general anaesthesia via drawover vaporiser (no electrocautery available during ether)
5. Surgeon and assistant perform surgical hand scrub with soap and ethanol
6. Reusable fabric drapes and gowns
7. Incision with resharpened scalpel blade on reusable handle
8. Dissection and appendicectomy using standard reusable instruments (forceps, scissors, retractors, clamps)
9. Haemostasis by clamping and tying with catgut or silk ligatures (no electrocautery with ether)
10. Wound closure: peritoneum and fascial layers with chromic catgut continuous suture; skin with interrupted silk or catgut sutures, using eyed needles
11. Wound dressed with locally produced gauze and wool dressing, secured with cotton bandage
12. Recovery: longer than modern practice (ether recovery takes 30–60+ minutes, with significant nausea). Postoperative antibiotics if available; otherwise wound monitoring and early intervention if infection develops
13. All instruments cleaned, inspected, sharpened if needed, and autoclaved for next case

The performance gap is real but manageable:

• Operating time is longer (no electrocautery means more time on haemostasis; ether induction is slower; instrument handling is different with eyed needles and catgut)
• Infection rate is higher — perhaps 5–15% surgical site infection rate for clean-contaminated cases, compared to 2–5% with modern antisepsis and prophylactic antibiotics⁵¹
• Range of procedures is narrower — complex cardiac, neurosurgical, and microsurgical procedures are severely limited or impossible without modern sutures, instruments, and monitoring
• But appendicectomy, caesarean section, hernia repair, fracture fixation, limb amputation, drainage of abscesses, bowel obstruction relief, and most general surgical emergencies remain feasible

This is roughly the surgical capability of a well-equipped hospital in the 1940s–50s. Patients survived these procedures then. They will survive them now.

8.4 Surgical triage under consumable scarcity

As consumable supply tightens, not all patients who would receive surgery under peacetime conditions can be operated on. Triage decisions must be made explicitly, not left to ad hoc rationing by individual surgeons.

Triage principles (anchored to recovery goals):

1. Life-threatening conditions first. Emergency surgery for immediately life-threatening conditions — ruptured appendix, obstetric emergencies, traumatic haemorrhage, bowel obstruction — receives highest priority for consumable allocation regardless of patient age or status. Without surgery, these patients die.

2. Workforce-critical conditions second. Surgery that returns a patient to productive function within the recovery workforce — fracture fixation, hernia repair, abscess drainage, wound debridement — receives priority because the recovery depends on a functional working population. This is a resource allocation decision grounded in the shared goal of societal recovery.

3. Expected benefit duration matters. When consumable supply forces a choice between two patients with comparable conditions, expected years of post-operative benefit is a legitimate consideration. A caesarean section (two lives, decades of expected benefit) takes priority over a hip replacement for a patient with limited life expectancy. This must be stated openly, not implemented through quiet clinical discretion.

4. Elective and quality-of-life surgery last. Procedures that improve quality of life but are not life-threatening or workforce-critical — cosmetic procedures, some joint replacements, some benign tumour excisions — are deferred until consumable supply is adequate. This is already standard emergency triage practice; the difference is that the “emergency” extends for years.

5. Transparent criteria, not individual discretion. Surgical triage categories should be published nationally by the Chief Medical Officer and applied consistently across hospitals. Leaving triage to individual surgeon discretion produces inconsistent outcomes and erodes trust — one hospital operates on a condition that another hospital refuses. Published criteria, even imperfect ones, are better than silent rationing.

Societal acceptance. Surgical rationing is more easily understood than pharmaceutical rationing because people already accept the concept of surgical waiting lists and emergency triage. The extension to consumable-based triage is a difference of degree, not kind. Clear communication about why certain surgeries are deferred — and what the timeline is for resumption as local consumable production ramps up — helps maintain public confidence in the surgical system.

---

9. IMPLEMENTATION TIMELINE

Phase 1 — Months 0–12

Action	Timeline	Lead	Dependencies
National surgical consumable inventory	Days 1–14	Te Whatu Ora / Health NZ, hospital procurement	Doc #1
Implement consumable rationing protocols	Days 1–30	Hospital surgical departments, CSSDs	Inventory data
Suspend non-urgent elective surgery	Days 1–7	Chief Medical Officers	Government directive
Switch to reusable drapes and gowns	Weeks 1–8	Hospital laundry services, CSSDs	Existing linen stock or rapid procurement of fabric
Begin autoclave maintenance audit	Weeks 2–4	Biomedical engineering departments	Existing capacity
Identify and reserve chromium salts for catgut production	Weeks 2–4	Chemical supply audit	National stockpile data
Begin training in ether anaesthesia, regional anaesthesia maximisation	Months 1–6	Anaesthesia departments	Textbooks, experienced clinicians
Establish surgical instrument maintenance workshops	Months 1–6	CSSD managers, hospital engineering	Sharpening equipment, magnification
Begin pilot catgut suture production	Months 3–12	Surgical department in collaboration with meat processing	Sheep intestine, alkali, iodine, ethanol
Begin ethanol production for antiseptic use	Months 3–12	Distilling operations (may be coordinated nationally)	Fermentable feedstock, distillation equipment
Assess NZ mulberry tree stock for future sericulture	Months 6–12	Plant & Food Research, DOC, botanic gardens	Low priority but worth early assessment

Phase 2 — Years 1–3

Action	Timeline	Lead	Dependencies
Scale catgut suture production to meet clinical demand	Years 1–2	Designated production centres (likely co-located with major meat works)	Raw materials, quality testing capability
Establish ether production	Years 1–2	Chemical production (linked to ethanol and sulfuric acid programmes)	Ethanol, sulfuric acid, glassware
Manufacture drawover ether vaporisers	Years 1–2	Engineering workshops (Doc #91)	Metal-working capability, design specifications
Transition to ethanol-based surgical antisepsis	As chlorhexidine/povidone-iodine stocks deplete	Hospital pharmacy, infection control	Ethanol supply
Develop seaweed-derived iodine production	Years 2–3	Coastal communities, chemistry capability	Kelp harvesting, chemical processing
Scale dressing production — wool, harakeke, cotton blend	Years 1–3	Textile production (linked to Doc #100)	Fiber processing, weaving, hospital CSSD
Convert glass syringe stocks for clinical use; begin glass syringe production if feasible	Years 2–3	Glassworking capability	Borosilicate glass stock or production
Establish surgical instrument fabrication capability	Years 2–3	Workshops with metallurgical capability	NZ steel, heat treatment, precision grinding
Begin hypochlorite production for disinfection	Years 1–2	Linked to broader chemical production	Electricity, salt

Phase 3 — Years 3–7

Action	Timeline	Lead	Dependencies
Catgut and ether production routine and meeting demand	Years 3–5	Production centres	Established
Sericulture pilot production (if mulberry and silkworm stock available)	Years 3–5	Agricultural/textile production	Mulberry plantations, silkworm stock
Linen flax cultivation and processing	Years 3–7	Agricultural sector	Seed stock, processing equipment
Surgical instrument manufacturing for replacement and expansion	Years 5–7	Metalworking sector	Steel quality, heat treatment capability
Surgical training adapted to recovery-era consumables and techniques	Ongoing	Medical schools, hospital training	Trained surgeons passing on adapted skills

---

CRITICAL UNCERTAINTIES

Uncertainty	Impact if wrong	Resolution method
Actual in-country surgical consumable stock levels	Over-estimate leads to earlier-than-expected depletion; under-estimate leads to unnecessarily aggressive rationing	National inventory (Section 9, Phase 1). Single highest-priority information task for surgical planning
Catgut suture quality achievable from NZ sheep intestine	If tensile strength or consistency is poor, some surgical applications may lack adequate suture material	Pilot production and mechanical testing (tensile testing of production samples against known suture specifications). Begin in Phase 1
Ether production feasibility timeline	If sulfuric acid production is delayed, ether production is delayed. Gap between volatile agent depletion and ether availability could leave NZ dependent on ketamine alone for general anaesthesia	Prioritise sulfuric acid production in chemical industry development. Maintain strategic reserve of sevoflurane/isoflurane for essential cases
Autoclave lifespan without imported parts	If autoclaves fail faster than expected and repairs are not feasible, sterilisation capability degrades. This affects everything in this document	Autoclave audit in Phase 1. Spare parts inventory. Training in manual autoclave operation. Pressure cooker fallback
Surgical infection rates with degraded antisepsis and no gloves	If infection rates rise more than expected (above 15–20%), surgery may become net-harmful for some procedure categories	Surgical site infection surveillance. Adjust surgical indications based on observed complication rates. Maintain strict hand antisepsis
Surgeon and anaesthetist adaptation to recovery-era techniques	If clinicians cannot adapt from modern to historical techniques, surgical output drops	Training begins in Phase 1. Senior surgeons with experience in resource-limited settings (military, humanitarian) are invaluable — identify and retain them
NZ’s ability to produce sulfuric acid from geothermal sulfur	If sulfuric acid production fails or is delayed, both ether and chromic catgut production are affected	This is a critical industrial chemistry dependency. Multiple approaches to sulfuric acid should be pursued
Nuclear winter effect on sheep farming and intestine supply	If sheep numbers decline significantly under nuclear winter, catgut raw material supply is affected	Doc #74. Even with significant herd reductions, millions of sheep will still be processed annually
Patient acceptance of historically-based surgical care	Patients accustomed to modern surgery may refuse procedures or lose confidence in surgical care	Honest communication about what has changed and why. Transparency about infection rates. Visible competence and professionalism

---

Cross-References

Direct Dependencies — This Document Depends On

Doc #116 — Pharmaceutical Rationing Surgical consumable rationing and pharmaceutical rationing are conducted under the same national inventory and prioritisation framework. Antibiotic availability (Doc #116) directly affects the management of surgical site infections — when prophylactic and therapeutic antibiotics are rationed, surgical infection rates rise, which in turn increases the volume and severity of cases requiring surgical drainage and debridement. The two programmes must be co-ordinated: anaesthetic agent stocks are pharmaceutical items covered by Doc #116 and are tracked through the same inventory system.

Doc #100 — Harakeke Fiber This document depends on harakeke fibre processing capacity (Doc #100) for wound-contact dressing production. Muka cloth is the preferred wound-contact layer for surgical dressings because of its smoothness and natural antibacterial properties. Doc #100 governs the cultivation, harvesting, and processing pipeline from plant to fibre; this document governs the subsequent conversion of processed fibre into sterile surgical textiles. The dependency is direct: dressing production cannot outpace harakeke fibre processing throughput.

Doc #104 — Clothing and Textile Production Gauze and surgical drape production uses the same weaving infrastructure and overlapping labour pools as clothing production (Doc #104). Wool scouring, carding, spinning, and weaving capacity must be allocated between medical and non-medical textile needs. Doc #104’s production planning should explicitly include a medical textiles allocation — the two programmes should share infrastructure rather than competing for it.

Doc #91 — Machine Shop Operations Fabrication of ether vaporisers (EMO-type drawover units), autoclave replacement parts (door gaskets, valve springs, chamber repairs), surgical instrument manufacture (retractors, scalpel handles, simple forceps), and surgical needle maintenance equipment all depend on metal workshop capability described in Doc #91. This document identifies what needs to be fabricated; Doc #91 describes the capability base from which fabrication can occur.

Doc #74 — Pastoral Farming Sheep intestine for catgut suture production is a direct byproduct of the pastoral meat processing system described in Doc #74. Tallow from sheep and cattle is the fat source for locally produced surgical soap. Herd size projections from Doc #74 determine the long-term catgut raw material supply — any significant reduction in sheep processing throughput (through herd reduction, feed shortages, or disruption of meat processing facilities) directly reduces suture production capacity.

Direct Dependencies — Documents That Depend On This One

Doc #118 — Anaesthesia and Anaesthetic Agents Doc #118’s coverage of anaesthetic agent management depends on this document’s treatment of ether production, ketamine conservation, and regional anaesthesia extension. The ether production pathway described here (ethanol synthesis → sulfuric acid catalyst → ether dehydration → purification) is the enabling technical foundation for the anaesthetic capability described in Doc #118. These documents should be read together; the division is administrative, not technical.

Doc #121 — Dental Care Dental surgery shares sterilisation infrastructure (autoclaves, chemical disinfectants, surgical instruments) and some consumable categories (sutures, local anaesthetics, dressings) with general surgery. Dental care’s survivable scope under recovery conditions depends on the same sterilisation maintenance and consumable rationing systems described here.

Doc #123 — Midwifery and Obstetric Care Caesarean section is explicitly identified in this document as a life-saving priority procedure that must remain feasible throughout the recovery period. Doc #123’s midwifery and obstetric planning must account for surgical consumable availability — the consumable budget for obstetric surgery (sutures, drapes, anaesthetic agents, antiseptics) is part of this document’s allocation framework. The interface between community midwifery (Doc #123) and hospital obstetric surgery (this document) is the decision point at which consumable allocation affects outcomes.

Doc #126 — Medical Devices Surgical instruments and anaesthetic machines are medical devices; their maintenance, repair, and eventual fabrication overlap with Doc #126’s scope. Specific overlap areas: autoclave maintenance and spare parts, reusable surgical instrument management, anaesthetic machine adaptation for ether use. Doc #126 should cross-reference this document for sterilisation-specific equipment management.

Doc #119 — Local Pharmaceutical Production The long-term prospect of locally synthesised local anaesthetics (lidocaine or procaine) would substantially restore regional anaesthesia capability, reducing dependence on ether and ketamine for operations currently performed under spinal or nerve block anaesthesia. Doc #119’s pharmaceutical synthesis programme should treat local anaesthetic synthesis as a medium-high priority given its surgical enabling value. The dependency runs from this document toward Doc #119: surgical capability through Phase 3–5 improves substantially if local anaesthetic synthesis is achieved.

Contextual Relationships

Doc #116 — Pharmaceutical Rationing — rationing protocols for surgical consumables mirror the pharmaceutical rationing framework; unified national rationing authority is preferred over separate surgical and pharmaceutical systems.

Doc #1 — National Emergency Stockpile Strategy — surgical consumable stocks are part of the national requisition and stockpile database. The inventory imperative in this document’s Recommended Actions is an instance of the broader stockpile strategy in Doc #1.

Doc #156 — Census — identifying surgeons, anaesthetists, CSSD technicians, biomedical engineers, instrument technicians, and textile workers with relevant skills is a census task. Skills identification precedes workforce deployment; Doc #156 is the upstream dependency for all workforce estimates in this document’s Economic Justification section.

---

---

1. Ministry of Health / Te Whatu Ora — Health NZ. Publicly reported surgical procedure volumes. NZ hospitals perform approximately 300,000–400,000 inpatient and day-case surgical procedures per year. The exact number varies by year and by what is counted as a “surgical procedure.” This figure includes all specialties and both public and private hospitals.↩︎

2. Estimate based on NZ hospital procurement data. Major suture manufacturers supplying NZ include Ethicon (Johnson & Johnson), Medtronic (formerly Covidien), and B. Braun. NZ’s total suture consumption is not publicly reported; the estimate is based on procedure volumes and typical suture-per-case consumption rates.↩︎

3. NZ surgical and examination glove consumption estimated from hospital procurement volumes and international benchmarking. NZ hospitals use approximately 5–10 million pairs of gloves per year across all clinical settings (surgical, examination, procedural). NZ does not manufacture latex or nitrile surgical gloves; no NZ-based glove manufacturer has been confirmed in public procurement records. This figure requires verification from Te Whatu Ora procurement data.↩︎

4. Sevoflurane is the dominant volatile anaesthetic agent in NZ. Annual consumption across NZ’s public and private hospitals is not publicly reported. Rough order-of-magnitude estimate: NZ performs approximately 300,000–400,000 procedures per year; perhaps 100,000–150,000 involve general anaesthesia with volatile agents; at 20–100 mL sevoflurane per operating hour and typical procedure durations of 1–3 hours, consumption ranges from approximately 2,000–45,000 litres per year. The wide range reflects uncertainty in procedure mix and technique; the table entry “thousands of litres” is a lower-bound description. Actual consumption data would require Te Whatu Ora procurement records.↩︎

5. Surgical consumable stock levels are held by hospital procurement departments and distributors. They are not publicly aggregated at national level. The 1–6 month range is estimated from standard supply chain management practices for medical consumables in NZ.↩︎

6. EBOS Group. https://www.ebosgroup.com/ — NZ/Australian healthcare company with significant medical device and consumable distribution alongside pharmaceutical wholesale. Also handles veterinary supplies.↩︎

7. Poole D, et al. “Reprocessing and reuse of single-use medical devices: systematic review and implications for policy.” Medical Journal of Australia 193(7):406–411, 2010. Also: US FDA guidance on reprocessing of single-use devices. The practice of reprocessing single-use devices is common in many countries (including regulated reprocessing in the US and Germany) and is supported by evidence when appropriate protocols are followed.↩︎

8. Korniewicz DM, et al. “Integrity of vinyl and latex procedure gloves.” Nursing Research 39(3):144–146, 1990. Glove integrity degrades with use; microperforation rates increase with duration of use and with reprocessing. Autoclaving latex gloves causes protein denaturation and increased perforation risk.↩︎

9. Lister J. “On the Antiseptic Principle in the Practice of Surgery.” Lancet 90(2299):353–356, 1867. Halsted WS. “Rubber Gloves in Aseptic Surgery.” Annals of Surgery 30(2):277–278, 1899. The period between Lister’s antiseptic revolution (1867) and Halsted’s introduction of rubber gloves (1890s) saw surgery performed with bare hands under rigorous chemical antisepsis. Infection rates were dramatically lower than pre-antiseptic surgery, though higher than modern gloved technique.↩︎

10. NZ surgical and examination glove consumption estimated from hospital procurement volumes and international benchmarking. NZ hospitals use approximately 5–10 million pairs of gloves per year across all clinical settings (surgical, examination, procedural). NZ does not manufacture latex or nitrile surgical gloves; no NZ-based glove manufacturer has been confirmed in public procurement records. This figure requires verification from Te Whatu Ora procurement data.↩︎

11. Standards NZ / AS/NZS 4187:2014 — Reprocessing of reusable medical devices in health service organisations. This standard governs sterilisation practice in NZ hospitals and specifies requirements for steam sterilisers (autoclaves) used in healthcare.↩︎

12. Boiling water sterilisation: standard microbiological references. Boiling (100°C at atmospheric pressure) kills vegetative bacteria, most viruses, and many fungi within minutes, but does not reliably destroy bacterial endospores (notably Clostridium species). Tyndallisation (repeated boiling over several days) improves spore kill but is impractical for routine surgical use.↩︎

13. Pressure cooker sterilisation has been validated in multiple studies for resource-limited settings. See: Rutala WA, Weber DJ. “Guideline for Disinfection and Sterilization in Healthcare Facilities.” CDC/HICPAC, 2008. A pressure cooker achieving 121°C for 15–20 minutes provides equivalent sterilisation to a gravity-displacement autoclave.↩︎

14. Dry heat sterilisation: effective at 160°C for 2 hours or 170°C for 1 hour. Standard microbiological sterilisation reference. Less efficient than moist heat (steam) because dry heat transfers energy to microorganisms more slowly. Suitable for items that cannot tolerate moisture.↩︎

15. Glutaraldehyde (2% alkaline solution, e.g., Cidex) achieves high-level disinfection in 20–45 minutes and sterilisation in 10+ hours at room temperature. Ethylene oxide gas sterilisation operates at 30–60°C and is used for heat-sensitive and moisture-sensitive items. Both agents are imported and finite. Rutala WA, Weber DJ. CDC/HICPAC guideline (2008).↩︎

16. Boiling water sterilisation: standard microbiological references. Boiling (100°C at atmospheric pressure) kills vegetative bacteria, most viruses, and many fungi within minutes, but does not reliably destroy bacterial endospores (notably Clostridium species). Tyndallisation (repeated boiling over several days) improves spore kill but is impractical for routine surgical use.↩︎

17. Belkin NL. “Surgical drapes and gowns: A historical perspective.” Infection Control & Hospital Epidemiology 16(11):644–650, 1995. Cotton muslin with a thread count of 140 per inch was the standard surgical drape material for decades. Its barrier properties are inferior to modern disposable materials (liquid strike-through occurs) but adequate when used in multiple layers.↩︎

18. Stats NZ. NZ sheep population approximately 25–26 million head (2023–2024 data). Down from a peak of approximately 70 million in the 1980s but still substantial — NZ has approximately 5 sheep per person.↩︎

19. Wool can withstand autoclave temperatures (121–134°C). The protein structure of wool (keratin) tolerates brief exposure to steam sterilisation. Some felting and shrinkage occurs; fabrics should be pre-shrunk before first clinical use. See: Textile Institute resources on wool properties; also practical experience from historical surgical linen management.↩︎

20. Riley M. Maori Healing and Herbal. Viking Sevenseas NZ Ltd, 1994. Harakeke was used in rongoā Māori (traditional medicine) for wound management, including as poultices and dressings. The antibacterial properties of harakeke fibre have been investigated in NZ laboratory studies; specific citation requires verification — the “Brook FJ, et al.” reference in earlier drafts of this document was not confirmed against a published NZ Journal of Botany article and should be treated as unverified until the primary source is identified. The rongoā Māori use is well-attested; the specific antimicrobial mechanism warrants expert review before clinical claims are made.↩︎

21. Linen flax (Linum usitatissimum) was grown commercially in Canterbury and Southland during the early–mid 20th century, particularly during World War II when imported textiles were scarce. The crop fell out of production after the war. NZ’s climate is suitable for linen flax, particularly in the South Island. Seed stock may be available from Plant & Food Research or from the NZ seed bank (Margot Forde Germplasm Centre at Palmerston North).↩︎

22. Ministry for Primary Industries / NZ Forest Owners Association. NZ has approximately 1.7 million hectares of plantation forest, predominantly Pinus radiata. Pine resin (rosin) is a byproduct of the timber industry and can be tapped from living trees. NZ was not historically a significant rosin producer, but the raw material is abundant.↩︎

23. Gurowitz M. “Johnson & Johnson History — The First Adhesive Tape.” Kilmer House blog, Johnson & Johnson corporate history. The first commercial surgical adhesive tape (1886) used a rubber-rosin adhesive on a cotton fabric base.↩︎

24. Mackenzie D. “The history of sutures.” Medical History 17(2):158–168, 1973. Catgut sutures were the dominant absorbable suture material from the 1800s until the 1970s. Joseph Lister pioneered the use of carbolic-acid-sterilised catgut in the 1860s. Chromic catgut (treated with chromium salts) was introduced in the early 20th century.↩︎

25. Stats NZ. NZ sheep population approximately 25–26 million head (2023–2024 data). Down from a peak of approximately 70 million in the 1980s but still substantial — NZ has approximately 5 sheep per person.↩︎

26. Sheep small intestine length is approximately 20–25 metres. This is consistent across breeds and is well-established in veterinary anatomy. Not all of this length yields suture-grade submucosa — the jejunum and ileum provide the best material.↩︎

27. The submucosa of sheep small intestine is a collagen-rich layer approximately 0.1–0.3 mm thick. Isolation of the submucosa by alkaline treatment and mechanical scraping is a standard process used in both surgical catgut and sausage casing production. See: standard surgical catgut manufacturing references and sausage casing production literature.↩︎

28. Chromic treatment cross-links collagen fibers using trivalent chromium, increasing tensile strength and resistance to enzymatic absorption. This is the same chemistry used in leather tanning (chrome tanning). Chromic catgut absorbs in approximately 20–40 days, compared to 7–10 days for plain catgut. Standard surgical catgut manufacturing references.↩︎

29. Sterilisation of catgut by iodine-alcohol immersion: historical standard method. See: US Pharmacopeia references on catgut sterilisation; also Mackenzie (1973). The iodine-alcohol method was used from the early 20th century through the 1960s before industrial gamma-irradiation sterilisation became standard.↩︎

30. Silk sutures: standard surgical reference. Silk has been used as a surgical suture material since at least the 2nd century AD. Braided silk sutures were the dominant non-absorbable suture material through the mid-20th century. They handle well but produce more tissue reaction than synthetic non-absorbable materials.↩︎

31. Sericulture in New Zealand: mulberry trees (Morus alba, M. nigra) grow in NZ, particularly in the North Island. There have been small-scale sericulture experiments in NZ but no established industry. Silkworm eggs (Bombyx mori) are available from hobbyist suppliers and educational supply companies in NZ and Australia.↩︎

32. Mulberry tree (Morus alba, M. nigra) growth rates: seedlings typically reach 2–3 m height in 3–5 years under NZ conditions, with productive leaf yield beginning at 2–4 years from seedling. Sources: general horticultural references for Morus species; NZ climate is broadly suitable for mulberry cultivation in the North Island and northern South Island. The 3–5 year timeline for productive size is a general horticultural estimate; actual performance in NZ conditions has not been formally studied at the scale needed for sericulture and requires verification from Plant & Food Research or NZ horticulture expertise.↩︎

33. Anaesthetic stock estimates in this table are based on general knowledge of NZ hospital procurement patterns and have not been verified against Te Whatu Ora procurement data or distributor inventory records. Actual stock levels are held by hospital pharmacies, Te Whatu Ora central procurement, and distributors (Fisher & Paykel Healthcare, Baxter, and others); they are not publicly aggregated. The national pharmaceutical inventory (Doc #116) must include anaesthetic agents. All durations in this table should be treated as order-of-magnitude estimates pending inventory verification.↩︎

34. Low-flow anaesthesia: Baxter AD. “Low and minimal flow inhalational anaesthesia.” Canadian Journal of Anaesthesia 44(6):643–653, 1997. Using fresh gas flows of 0.5–1.0 L/min (versus the traditional 2–6 L/min) reduces volatile agent consumption by 50–75% with modern anaesthetic machines equipped with circle breathing circuits and soda-lime CO₂ absorbers.↩︎

35. Ketamine: Green SM, et al. “Clinical practice guideline for emergency department ketamine dissociative sedation.” Annals of Emergency Medicine 57(5):449–461, 2011. Also: WHO Model List of Essential Medicines — ketamine is included as an essential anaesthetic. Its safety profile and versatility make it particularly valuable in resource-limited settings.↩︎

36. Ether anaesthesia: Keys TE. The History of Surgical Anesthesia. Schuman, 1945 (reprinted). Diethyl ether was first used as a surgical anaesthetic by Crawford Long (1842) and publicly demonstrated by William Morton (1846). It remained in widespread use for over a century.↩︎

37. Ether MAC values: Diethyl ether MAC in adults is 1.92% (at 1 atm). Comparison volatile agent MACs: sevoflurane 2.05%, isoflurane 1.15%, halothane 0.75%. Source: Stoelting RK, Hillier SC. Pharmacology and Physiology in Anesthetic Practice, 4th ed. Lippincott Williams & Wilkins, 2006. Standard anaesthesia pharmacology reference.↩︎

38. Ether flammability: ether vapour has a flash point of -45°C and forms explosive mixtures with air at concentrations of 1.9–36% by volume. The transition away from ether in developed countries was driven partly by the desire to use electrocautery safely in the operating room. In recovery-era practice, accepting the loss of electrocautery during ether cases is the necessary trade-off.↩︎

39. Ethanol production from fermentation: any sugar or starch source can be fermented to produce ethanol. NZ has multiple potential feedstocks: grain (barley, wheat — NZ grows both), sugar beet (historically grown in NZ), potatoes, fruit waste. Distillation to 95%+ concentration requires standard distillation equipment — column stills are most efficient. NZ’s craft distilling sector provides both equipment and skilled operators — the number of licensed NZ distilleries has grown substantially since 2010 and is estimated at 50–80 operations as of 2024, but this figure requires verification from the NZ Customs/Excise licensing register as the sector is not centrally catalogued in a publicly accessible form.↩︎

40. Sulfuric acid production: the contact process (SO₂ + O₂ → SO₃ over a vanadium pentoxide catalyst, then SO₃ + H₂O → H₂SO₄) or the older lead chamber process are both feasible with NZ materials. Elemental sulfur is available from NZ’s geothermal areas (Rotorua, Taupo Volcanic Zone). NZ has historical precedent for sulfur extraction — sulfur was mined at White Island (Whakaari) and in the Rotorua area in the 19th and early 20th century.↩︎

41. Ether peroxide formation: ether exposed to air and light forms diethyl ether peroxide, which is shock-sensitive and explosive when concentrated. Prevention: store in dark, full containers with minimal air headspace; add a small amount of copper wire (which catalytically decomposes peroxides) or BHT stabiliser. Test for peroxides before use (potassium iodide starch paper — turns blue in the presence of peroxides). Standard chemical safety reference.↩︎

42. Ether consumption during anaesthesia: approximately 50–200 mL of liquid ether per hour of anaesthesia, depending on vaporiser efficiency, circuit type (open, semi-open, closed), and patient factors. Closed-circuit techniques with CO₂ absorption minimise ether consumption.↩︎

43. EMO (Epstein-Macintosh-Oxford) vaporiser: a temperature-compensated drawover vaporiser designed for field use with diethyl ether. Robust, no moving parts, no power requirement. Developed in the 1950s and used widely by military and developing-country anaesthesia services. Design specifications are published and the device can be fabricated in a metal workshop.↩︎

44. Schimmelbusch mask: a wire-frame mask covered with gauze, onto which ether is dripped. Named after Curt Schimmelbusch (1860–1895). The simplest possible ether administration device. Concentration control is entirely by operator judgment (speed of dripping, number of gauze layers, proximity to face). Works but wastes ether and exposes theatre staff.↩︎

45. Ethanol neurolysis: injection of concentrated ethanol (50–100%) into or around a nerve produces permanent nerve destruction. Used historically for amputation pain relief and in palliative care for cancer pain. See: Koyyalagunta D, et al. “Chemical neurolysis for cancer pain.” Current Pain and Headache Reports 11(4):265–269, 2007.↩︎

46. Darouiche RO, et al. “Chlorhexidine-alcohol versus povidone-iodine for surgical-site antisepsis.” New England Journal of Medicine 362(1):18–26, 2010. Chlorhexidine-alcohol is the current evidence-based standard for surgical skin preparation, superior to povidone-iodine in clinical trials.↩︎

47. Ethanol as a surgical antiseptic: 70–80% ethanol is effective against most bacteria, viruses (including enveloped viruses), and fungi. It is less effective against bacterial spores than chlorhexidine or iodine. Contact time of 2+ minutes is recommended for surgical antisepsis. WHO Guidelines on Hand Hygiene in Health Care (2009) endorse alcohol-based hand rub as the standard for surgical hand preparation.↩︎

48. Iodine from seaweed: iodine was first isolated from kelp ash by Bernard Courtois in 1811. Seaweed-derived iodine was the primary industrial source until the early 20th century, when Chilean saltpetre deposits and later brine extraction became dominant. NZ’s kelp species (primarily Macrocystis pyrifera and Durvillaea species) contain 0.1–0.5% dry weight iodine. Extraction requires burning dried kelp, leaching ash, and precipitating iodine.↩︎

49. Electrolytic hypochlorite production: electrolysis of brine (NaCl solution) produces sodium hypochlorite (NaOCl) and hydrogen gas. Small-scale electrolytic generators are used worldwide for water treatment and are simple to construct with available materials (electrodes, a power source, salt, and water). NZ’s continued electrical grid availability enables this.↩︎

50. Dakin’s solution: developed by Henry Dakin (chemist) and Alexis Carrel (surgeon) during World War I for wound irrigation. The solution is approximately 0.025–0.05% sodium hypochlorite, buffered with boric acid to pH 9.0 to reduce tissue toxicity. It was the standard wound antiseptic for decades and is still used in modern wound care. See: Carrel A, Dakin HD. “Treatment of Infected Wounds.” British Medical Journal 2(2918):541–545, 1915.↩︎

51. Surgical site infection rates: modern SSI rates for clean-contaminated procedures (e.g., appendicectomy) are approximately 2–5% with full modern antisepsis, prophylactic antibiotics, and sterile technique. Historical rates before antibiotics and modern antisepsis were 10–30%+. The recovery-era estimate of 5–15% reflects an intermediate state: good technique with suboptimal materials. See: National Nosocomial Infections Surveillance (NNIS) system data; also historical surgical infection literature.↩︎