By: Christy Pirone and Steve Goble

Last weekend I was parallel parking my van. The sidewalk protruded at the front wheel and space was tight, so I decided to accelerate to allow the wheel to drive over the curb and place the van perfectly in the spot. However, a loud crunching sound produced a rush of adrenalin within me. This prompted a reversal of my action with the all too familiar dread of finding a dent in my car. What I had not seen was a signpost that was being bent by my front bumper. Luckily there was no damage to the car.

Thirty minutes later I parallel parked at another location. I jumped out of the van in a rush and was approached by a lady on the sidewalk. She said “We were watching you parallel park and were amazed at how well you perfectly performed the task.” I was stunned.

Upon reflection, however, it is not much different from our work in hyperbarics. For example, you’re in a rush and at the very moment you are trying to start a treatment you seem to be the only person that has the answer to anything anybody urgently needs to know. The patient gets loaded into the chamber and you can now focus on the task.

Just as the chamber begins pressurization, you see it. The patient did not remove their hearing aid before going into the chamber. That same familiar feeling of dread hits you and you know the chamber has to be depressurized, the hearing aid removed, and your error exposed. Of course there was no harm done, it was after all just human error.

Human error is the most common cause of adverse events. However, as with the examples discussed previously, error does not necessarily incur harm. Errors can be detected and corrected to prevent harm. Allnut (1987 p 851)1 eloquently describes error in humans, “….all human beings, without any exception whatever, make errors and that such errors are a completely normal and necessary part of human cognitive function.”

To prevent future errors, there is little benefit in attributing blame to the individuals that happen to be present when an adverse event occurs.2 The commitment and education of workers in the medical profession is unquestionable. It is considerably more effective to target the systems that the individual works within. Safeguards can be implemented to prevent human error. Systems-based approaches to error analysis have been developed and are used within high-risk industries to develop safe work practices. Such an approach can also be used in hyperbaric practice.

Consider the following incident that occurred recently. Prior to treatment, hyperbaric staff should measure blood sugar levels (BSL’s) on all diabetic patients to assess the risk of hypoglycemia. Due to staff working in a new area, pressure to proceed with the treatment, and distractions, the BSL’s were not performed. Normally this is not a problem because during the technician’s pre-compression checklist the inside attendant is asked whether the BSL’s have been done on diabetic patients. However, the checklist had been removed for cleaning and the technician had gone through the checklist from memory, omitting the BSL check. The nurse in charge happened to pass and asked about the BSL’s before the compression started and as a result there was a short delay while the problem was rectified. This incident was the culmination of a number of errors, despite having set procedures and a system of checks to prevent such an occurrence.

Little can be gained in error prevention unless we know what types of adverse events are occurring in the hyperbaric setting. It may be harmful to change practice in response to one sentinel event. It is better to look at a multitude of like events and analyze the causes of those events. It is unlikely that one unit would have the frequency of incidents to develop effective strategies to prevent similar errors. In order to develop effective preventative strategies a large number of similar incidents need to be collated and analyzed.

The Hyperbaric Incident Monitoring Study or HIMS has a proven record for the systematic collection of incidents that occur in hyperbarics. HIMS is an incident monitoring system designed to collect incidents that occur in patients, staff, and equipment in hyperbaric units.