Tag Archives: patient

27 Patients to be Tested After Ultrasound Probe Sterilization Error

By ThinkReliability Staff

On December 21, 2013, 27 men were notified that, due to improper sterilization of equipment used for their prostate procedures, they should be tested for HIV and hepatitis B and C.   Both the medical center and patients involved are understandably concerned about how they got to this point.

In order to better understand the issues involved, we can put together an investigation file using Cause Mapping, a visual form of root cause analysis.  First, we capture the basic information about the issue.

The procedures were performed from September 19 to December 10 of this year at a Seattle medical center and involved ultrasound probes used for prostate procedures.  Because more than one date is involved, we can use a timeline to add more detail to the investigation.  In this case, patients were found to have been affected beginning September 19 and ending December 10, though it’s not clear if the incorrect sterilization began on that date, or if that was the first date that a probe was used on a patient with a communicable disease.  The improper sterilization was reported to hospital officials December 17 and affected patients were notified beginning December 21st.  As a result of information released by the medical center, we know that one step in the sterilization process for the probes was not completed.  We capture this as an important “difference” that may aid in the analysis.

Next, we determine the goals that were impacted as a result of the issue.

The patient safety and patient services goals were impacted due to the risk of disease transmission for the 27 patients (the probability of which is estimated to be very low).  The compliance goal is impacted because of equipment that was not sterilized as required.  The labor goal is impacted because the medical center is paying for two rounds of HIV and hepatitis testing for the affected patients.  If it is determined over the course of the investigation that other goals were impacted as well, these can be captured in the Problem Outline as well.

Once we have determined the impacted goals, we use these goals as the first “effect” to determine the cause-and-effect relationships that resulted in the issue.  In this case, the patient safety and services goals were impacted due to the risk of disease.  The disease risk resulted from the reuse of prostate probes that had the possibility to spread disease.  The disease risk occurred because the probes may have been used on a patient that had a communicable disease and the probes were not properly sterilized before their reuse.

We can show the steps that should have occurred in the sterilization process of these probes, as well as where the specific issue in the process occurred, in a Process Map.  This map shows the steps involved in a procedure, in this case the ultrasound probe sterilization procedure.  After a probe is used, it goes through a three-step process, involving cleaning, disinfecting or decontaminating with a disinfectant spray, then sterilization by being doused with sterilization fluid.  Then the sterilized equipment is placed in a protective sheath before re-use.  (Because of the use of this protective sheath, the probe, when properly used, does not contact the patient, decreasing the risk of disease transmission.)  In this case, the sterilization step was not performed.

We include the fact that the procedure was not performed properly in the Cause Map.  The Chief Medical Officer reports that their investigation found that the cause was “human error” and no more information has been released.

In order to determine effective solutions to prevent the issue from recurring, more detail needs to be obtained about the expectations for the process being performed, as well as the verification (if any) that took place to ensure that the procedure was being performed correctly.  Once it’s possible to determine what allowed the process to break down, safeguards that will reduce the risk of it happening again can be implemented.

To view the initial investigation file, including the Outline, Cause Map, Timeline and Process Map, please click “Download PDF” above.