Failed Bowie-Dick test after weekend emergency treatment
On Monday at 08:00, the dental nurse records a failed Bowie-Dick test on autoclave A: the indicator sheet shows an uneven colour change, with a pale central area. The log shows the last passed Bowie-Dick test on Friday at 17:00. Autoclave A was used for six instrument packs during Saturday emergency sessions between 09:00 and 11:00, when four patients were treated: one extraction, one pulpotomy, and two restorations. Autoclave B passed its daily test and is available. The practice has no traceability system beyond the day's worksheet, which records patient names and the autoclave used but not the individual cycle number. The nurse asks whether the weekend patients need to be contacted and whether the instruments can simply be re-sterilised and used again.
1. What immediate actions should be taken with autoclave A and the instruments from the weekend?
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Take autoclave A out of service immediately, label it as quarantined, and arrange engineer validation before reuse. Do not run further cycles in it. Switch to autoclave B, which has passed its test.
Identify the six packs from Saturday. Any instrument pack that was processed but not used should be quarantined and reprocessed through a validated cycle before use. Instruments that were already used on patients cannot be made safe retrospectively by re-sterilising them; the concern is the cycle that processed them before use. Retrieve and quarantine any unused packs from that period, review the worksheet, and reconstruct which packs went to which patient as far as possible. Record all actions with times and names.
2. How would you assess the risk to the four patients and what would you tell them?
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The risk is low but not zero. A failed Bowie-Dick test suggests air removal or steam penetration may have been inadequate, so some instruments may not have been sterile. Risk depends on the procedures performed, whether instruments were visibly clean before cycling, and whether there was actual contact with blood or tissue. The extraction and pulpotomy are more invasive than the restorations.
I would seek advice from the local infection prevention and control team or dental public health, complete an incident review, and contact the four patients. Explain plainly that a steriliser test failed, that the risk is thought to be low, and that you are reviewing their records. Apologise for the uncertainty, offer a conversation with a clinician, and follow local guidance on blood-borne virus testing if indicated. Do not wait for the engineer's report before making a preliminary disclosure decision; document the advice received.
3. What corrective actions and records are needed?
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Record the failed test, the autoclave identifier, the last passed test, the affected patients, the packs, and the advice received. Complete an incident report and a root-cause analysis covering loading, air removal, door seals, chamber pressure, and operator training.
The corrective action plan should include:
- Engineer validation and repeat Bowie-Dick and biological/chemical indicators before return to service.
- A traceability system linking each patient to a cycle number and autoclave.
- Daily test logs with signed entries and action taken on failure.
- Staff training and a written policy for quarantining instruments after a failed cycle.
- An audit of the new process after implementation.
The practice should also review why weekend emergency work was undertaken without a passed test that day.