Findings of Incident at National Dental Centre where Unsterilised Instruments were Used on Patients

Dr Tan Wu Meng asked the Minister for Health regarding the National Dental Centre Singapore (NDCS) incident of instruments used on patients despite not completing the full sterilisation process (a) whether the Ministry has ascertained how the incident occurred and the chronology and decision-making process within NDCS when the incident was discovered; (b) whether the affected instruments could have been recalled faster; and (c) what lessons can be drawn from the incident.

Patient safety is of utmost importance to our public healthcare institutions. We apologise for the lapse at the National Dental Centre Singapore (NDCS) on 5 June and 6 June, which had led to the use of partially sterilised dental instruments.

SingHealth has conducted an investigation and the Ministry of Health (MOH) has received its report on 30 June 2017. The Ministry is reviewing the report and is also conducting its own investigation.

The SingHealth investigation showed that on the afternoon of 5 June, a staff of the Central Sterile Supplies Department (CSSD) of NDCS failed to complete all the steps in the sterilisation process for one batch of dental instruments. The batch of affected instruments were subsequently dispatched to the outpatient clinics at levels 2, 4 and 6 of NDCS.

Around 4.00 pm, another NDCS staff noticed that the sterilisation indicator tapes on some instrument packs had not changed colour, indicating that the sterilisation process has not been completed. She alerted the first NDCS staff as well as her immediate supervisor. An immediate attempt was made to recall the affected instruments. However, not all the affected instruments were retrieved.

On 6 June, before NDCS started operations at 8.00 am, the manager of CSSD checked the sterilisation records and detected the incomplete sterilisation of one batch of instruments on the previous day. She activated the department to retrieve all affected instruments from the clinics.

At 4.00 pm on 6 June, the manager of CSSD reported the incident to the senior management of NDCS. The Director of NDCS immediately activated another round of recalls to ensure that all affected instruments were retrieved. Prior to the start of clinic hours on 7 June, all dental instruments were thoroughly checked and confirmed to have undergone the complete sterilisation process. Additional controls, such as requiring a second person to check that the sterilisation process was completed, were also implemented.

Among the 714 patients who had visited the outpatient clinics on levels 2, 4 and 6 from the late afternoon on 5 June to the end of clinic hours on 6 June, up to 72 could have come into contact with the affected instruments as there were up to 72 sets of the affected instruments that had been used. As the first two steps of the sterilisation process were completed, including thermal washer disinfection which would remove close to 100% of organisms of concern, the risk of infection to patients was assessed to be extremely low.

NDCS dentists began contacting all of these patients on 10 June to inform them of the incident and reassure them on their low risk of infection.

From the findings, the incident originated from human error by a staff. In addition, her supervisor and department manager did not fully recognise the potential impact of the error. As a result, there was a delay in escalating the incident to senior management and up to 72 packs of affected instruments might have been used on patients, before all affected instruments were successfully recalled.

The findings also revealed procedural weaknesses and a lack of vigilance amongst some staff. At various points of the process, from the issuance of the instruments from CSSD, through the receipt of the instruments at the clinics, to the unpacking of the instruments before use on patients, the error could have been detected and an alert raised.

Following the incident, NDCS has instituted immediate corrective measures. Additional independent verifications have been put in place to ensure completeness of the sterilisation process. Clearer work instructions have been disseminated to all staff to ensure that the sterility of the dental instruments is checked prior to use.

NDCS has also audited their sterilisation records in the six months prior to the incident. The records confirmed that sterilisation was completed in all other cases. A check on the sterilisation equipment also indicated that it was fully functioning.

NDCS will strengthen the following: (a) standard operating procedures for sterilisation, handover and use of dental instruments; (b) documentation and inventory accounting process for sterilisation and movement of dental instruments from CSSD to the clinics, and (c) Incident escalation and reporting, recall and risk management frameworks.

In addition, NDCS will institute regular training and competency assessments for all staff involved in the sterilisation and handling of instruments to ensure familiarity with the processes.

Four NDCS staff directly involved in the incident, including supervisors and senior NDCS management, have been found to have fallen short in their level of vigilance and the speed in escalation of incident management. Disciplinary actions have been taken against them. These include warnings, as well as financial penalties.

The Ministry will review the findings of the SingHealth report, as well as our own investigation findings. We will consider if further regulatory actions are necessary. We will also closely monitor the implementation of remedial actions and standards of care at NDCS through regular audits.

While the risk of infection to affected patients is extremely low in this incident, it is a serious breach of the institution’s infection control system nonetheless. Our healthcare institutions need to be more vigilant and have a stronger reporting and incident escalation culture. These will enable us to detect and mitigate any incidents expeditiously. The learning points from this incident will be shared across the healthcare clusters so that we can collectively improve our standard of patient safety and care.