Sterilization

Part of Surgery

Eliminating microbial contamination from surgical instruments, surfaces, and materials to prevent infection.

Why This Matters

Before Joseph Lister introduced antiseptic surgery in 1867, post-operative infection killed 50-80% of patients who underwent major surgery. The bacteria causing these infections came from surgical instruments, the surgeon’s hands, dressings, and the operating environment. The organisms were there before germ theory was known — but without knowing the cause, surgeons could not address it.

Sterilization addresses the root cause: eliminating the microorganisms that cause post-surgical infection. In post-collapse conditions, without antibiotics to treat post-operative infections after they occur, prevention becomes the only strategy. A community healer who understands sterilization principles and applies them rigorously will have dramatically better surgical outcomes than one who does not — regardless of technical surgical skill.

The tools for adequate sterilization are simple: heat, alcohol, and time. No autoclave required.

Understanding What Sterilization Must Achieve

Types of Microorganisms to Eliminate

Vegetative bacteria: the active, dividing forms. Killed by:

• Boiling (100°C) within 1-5 minutes
• 70%+ alcohol contact (30+ seconds)
• Heat above 60°C for 30+ minutes

Bacterial spores: dormant, highly resistant forms produced by some bacteria (Clostridium — tetanus, gas gangrene; Bacillus). The major challenge. NOT killed by:

• Boiling alone (survive 100°C for hours)
• Alcohol at any concentration
• Most chemical disinfectants

Killed by:

• Pressurized steam above 121°C (autoclave) for 15-30 minutes
• Dry heat at 160-170°C for 1-2 hours
• 2% glutaraldehyde solution for 10 hours

Viruses: killed by boiling (some require higher temperatures), alcohol, and most disinfectants

Fungi: killed by boiling, alcohol, heat

The critical insight: routine surgical practice in a community without spore-forming wound contamination can achieve adequate safety through boiling. But when treating spore-contaminated wounds (soil-contaminated trauma, any injury where tetanus risk is high), spore elimination requires higher temperatures.

Sterilization Methods

Boiling

The most accessible sterilization method. Effective against all vegetative organisms.

Procedure:

1. Clean instruments thoroughly first — remove all visible blood, tissue, and debris (organic matter protects bacteria from heat)
2. Place instruments in a pot of water, fully submerged
3. Bring to a rolling boil
4. Maintain rolling boil (not just simmering) for minimum 30 minutes
5. Use immediately, or store in the boiling water until needed with pot covered
6. If instruments are contaminated after sterilization: re-boil before use

What can be boiled:

• Metal instruments: scalpels, forceps, clamps, needle holders, probes
• Glass syringes and needles (if needles are reused)
• Metal or glass bowls for instrument storage
• Metal wire suture

What cannot be boiled:

• Rubber (degrades rapidly)
• Plastic (melts or deforms)
• Sharp instrument edges (prolonged boiling dulls edges slightly — practical compromise)

Dry after boiling: instruments removed from water and left in air accumulate airborne contamination within minutes. Use immediately from the boiling water or dry with a clean (previously boiled) cloth and store in a covered sterile field.

Dry Heat Sterilization

More effective than boiling for spore elimination. Requires sustained high temperatures.

Procedure:

• Place instruments on a clean metal tray
• Place in an oven or enclosed heated space
• Maintain 160°C for 2 hours, or 170°C for 1 hour, or 180°C for 30 minutes
• Allow to cool in the sealed chamber before opening

Temperature verification: a sugar (sucrose) placed in the oven will caramelize at 165-175°C — provides a rough temperature verification without a thermometer.

Appropriate for: metal instruments, glassware, oil (petroleum jelly for wound protection is sterilized by dry heat — oil cannot be sterilized by boiling)

Alcohol Sterilization

70% ethyl alcohol (ethanol) or isopropyl alcohol kills vegetative bacteria and viruses within 30 seconds of contact. Does NOT kill spores.

70% vs 100%: Pure alcohol is actually less effective than 70% — water is needed to denature proteins. 70-80% concentration is optimal.

Producing 70% ethanol: Mix 95% distilled ethanol with water: 74 parts 95% ethanol + 26 parts water = 70% ethanol by weight. Or use high-proof spirit diluted appropriately.

Uses:

• Skin antisepsis before injection or incision
• Instrument rapid disinfection (soak for 30 minutes)
• Surface cleaning of operating field (tables, surfaces)
• Hand disinfection after handwashing

Limitations:

• Does not penetrate organic matter — must clean instruments before soaking
• Evaporates quickly — instruments must be used promptly or kept submerged
• Does not work on materials that cannot get wet (dressings, bandages)

Flame Sterilization

Brief flame exposure (passing through a flame or holding in flame until hot) kills surface bacteria. Not a reliable sterilization method for surgical instruments — provides only superficial kill and has no contact time.

Acceptable use: sterilizing a needle for very minor punctures (lancing a blister) when nothing else is available. Allow to cool before use — hot metal causes additional tissue damage.

Not acceptable for: surgical instruments, needles used for suturing, instruments entering body cavities.

Chemical Sterilization

When available, certain chemicals achieve sterilization including spore elimination.

2% Glutaraldehyde (“Cidex”):

• Soak instruments for 10 hours for full sterilization
• 20-30 minutes for high-level disinfection (kills most but not all spores)
• Rinse with sterile water before use (glutaraldehyde is tissue-irritating)
• Shelf life: 14-28 days once activated

Improvised antiseptic solutions:

• Dilute bleach (chlorine solution): hypochlorite at 0.5% concentration (1 part household bleach in 10 parts water) — high-level disinfectant, not sterilizer. Use for surface cleaning and non-invasive instruments.
• Hydrogen peroxide 3%: available in some pharmacies, kills bacteria and viruses. Soak instruments 20-30 minutes for disinfection (not full sterilization).

Maintaining a Sterile Field

Sterilizing instruments before surgery is necessary but not sufficient. The sterile field must be maintained throughout the procedure.

Setting Up

1. Use a clean surface (freshly scrubbed wood, or a clean cloth that has been boiled and dried)
2. Lay instruments on the sterile field from their sterilized container — do not set them on other surfaces first
3. Do not reach over the sterile field — pass items across from the side
4. If an instrument is dropped or touched by an unsterile hand, it is no longer sterile — resterilize or discard

Hand Preparation (Surgical Scrub)

The surgeon’s hands are never sterile — they can be significantly disinfected.

Surgical scrub technique:

1. Remove jewelry (rings, bracelets) — bacteria harbor under them
2. Wash hands and forearms thoroughly with soap and water for 5 full minutes
3. Use a clean brush or rough cloth on fingernails and nail beds (common contamination site)
4. Rinse from fingertips upward — water flows away from hands toward elbows, not the reverse
5. Final rinse: pour alcohol over washed hands and allow to dry
6. Keep hands above elbow level after scrubbing — contamination is reduced but not eliminated; don’t touch anything non-sterile

If using improvised gloves: even non-sterile gloves (boiled rubber, carefully handled cloth coverings) reduce transmission compared to bare hands. Wear them.

Minimizing Airborne Contamination

Talking, coughing, and breathing over the surgical field introduces bacteria.

• Work in still air if possible (outdoors in calm weather, or indoors without drafts)
• Cover mouth and nose with a close-fitting cloth covering
• Assistants not actively working should remain quiet and avoid facing the surgical field
• Keep the surgical field covered with a clean cloth until the moment of incision

Dressing and Wound Material Sterilization

Cloth dressings: boil for 20 minutes and allow to dry completely. Store in a clean sealed container. Use within 48 hours of sterilization if not in a sealed container.

Suture material (cloth thread, sinew):

• Pre-commercial suture was boiled linen or silk
• Boil natural fiber suture for 20 minutes
• Keep submerged in boiled water or high-proof spirit until use

Wound packing material (gauze, cloth): Boil, wring out, and allow to steam-dry in a covered clean vessel. This is not autoclave-sterile but adequate for most post-collapse settings.

Bandaging cloth: iron with a very hot iron if no boiling capacity — dry heat from an iron kills surface vegetative organisms (not spores). Acceptable for external bandaging; not adequate for direct wound contact in high-risk cases.

When Sterilization Fails

Recognizing that contamination occurred during surgery:

Signs that contamination occurred:

• Instrument dropped and used anyway
• Caregiver coughed or sneezed over the field
• Unsterile object contacted the surgical site

Response:

• Acknowledge it
• Irrigate the surgical site copiously with clean water
• Complete the procedure as efficiently as possible
• Use the longest available post-operative antibiotic course
• Monitor closely for wound infection

Document what happened. Infection rates over time reflect sterilization quality. If wound infections are occurring frequently, the sterilization process needs review.