A Failed Sterile Load at a 20-Bed Health Centre
The 20-bed primary health centre where you are posted has one horizontal autoclave. On Monday the OT assistant loads 12 gauze pads and a stainless-steel minor-surgery tray that was only rinsed under the tap after a dressing change, wraps everything in a cloth towel, and runs the cycle at 15 psi for 15 minutes. No indicator strip, autoclave tape or spore test is used. On Tuesday a child's blood-soaked dressing falls on the floor; a helper drops one bleaching-powder tablet into 5 litres of water and mops the area. A bottle of 5% sodium hypochlorite is on the shelf. The centre has no separation between the dirty and clean zones, and the same pair of scissors is used to cut the dressing and to trim the gauze that goes into the pack.
1. List the errors in the autoclave cycle and explain, for each, what could go wrong for the next patient.
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- No cleaning before sterilization. A rinsed tray still carries dried blood and protein, which shield bacteria and inactivate steam. The pack can pass the cycle and still infect a surgical wound - the commonest cause of 'sterilized' instruments causing surgical site infection.
- Cloth towel as the only wrap. A single cloth towel is not a validated sterile barrier; it stays damp after the cycle and wicks organisms from the air and shelf. Use paper/crepe pouches or a proper container with a filter.
- No chemical indicator inside or outside. Nothing shows that steam actually reached the pack, so a failed cycle looks identical to a successful one.
- No biological indicator. Only a spore test (Geobacillus stearothermophilus) proves the organisms were killed; without it the process is unverified.
- No printed or logged pressure, temperature and time. A gauge reading does not confirm the load itself held 121 °C for 15 minutes.
- Same scissors for dirty dressing and clean gauze - a direct fomite carrying wound organisms into the sterile field.
- No dirty/clean zoning - contaminated and sterile items share air and bench space.
2. Give the correct sequence for reprocessing the surgery tray, from the moment it leaves the patient to the moment it is stored, and state how you would verify the cycle worked.
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Sequence:
- At point of use: gloves on; sharps into a puncture-proof container; keep instruments moist (damp cloth or detergent soak) so blood does not dry.
- Transport in a closed, labelled container to the decontamination area, which must be physically separate from the clean packing area.
- Clean: disassemble, open hinges and joints, scrub under running water with detergent or enzymatic cleaner, brush and flush any lumens, then rinse with clean water and dry thoroughly - hinges and crevices included.
- Inspect: check for rust, cracks, stiffness and sharpness; lubricate hinges with instrument oil.
- Pack: place a chemical indicator strip inside, wrap in a validated barrier, seal with autoclave tape, label with date, cycle number and operator.
- Load without overfilling; packs upright, not touching chamber walls, so steam circulates.
- Sterilize at 121 °C, 15 psi, 15 minutes, followed by a full drying cycle.
- Unload and check: indicator colour change, pack dry, seal intact. Store in a closed dust-free cupboard - cloth-wrapped packs about 7 days, paper pouches longer according to local policy.
Verification is three-layered: physical (pressure/temperature/time record), chemical (internal strip and external tape), and biological (spore test weekly, with every implant load, and after any autoclave repair).
3. Calculate how to prepare 1 litre of 0.5% sodium hypochlorite from the 5% stock solution, and state the contact time and the safety precautions for the person mopping.
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Calculation: 5% ÷ 0.5% = a 1 in 10 dilution. For 1 litre of working solution, take 100 mL of 5% sodium hypochlorite and add 900 mL of clean cold water. This gives 0.5% (about 5,000 ppm available chlorine), the strength recommended for blood and body-fluid spills.
Method: wear gloves, a mask, an apron and eye protection; measure in a marked container in a ventilated area; add bleach to water, never water to bleach; never mix with acid, ammonia or other cleaners, which release chlorine gas. Prepare fresh at the start of each shift or each spill, label the container with strength and date, and discard after 24 hours because chlorine loses potency.
Contact time: flood the area, leave for 10 minutes (30 minutes for heavy or visibly soiled contamination), then wipe up from the outer edge inwards, clean with detergent, and allow to dry. The mop and bucket are then washed and dried and stored separately from cleaning equipment used in clinical areas.