HM was a 4-year-old girl with a complex history, including birth defects and cardiac problems. She was no stranger to the hospital, to the telemetry unit, or to its nurses. Nurse K carefully attended to her fragile patient, ensuring that each of the six ECG leads were properly placed on HM's small body. As soon as they were all in place, Nurse K gently folded the bed sheet over HM's frail torso, and tucked her into bed. After properly connecting the ECG leads to the patient, the final step was to plug them into the heart monitor, which would allow the nurses to observe HM's heart rhythm at the nursing station down the hall. After Nurse K lifted the guardrail on the side of the bed, she grabbed the ECG cord and scanned the head of the bed for the connection to the monitor. As was typical in this unit, there were several machines at the bedside—in this case, including an ECG machine and an IV infusion pump. The cord connected to the ECG leads in her hand had a characteristic six-pin connector at the end. It was designed such that it would fit perfectly with its counterpart. She grabbed the cord that was dangling down next to the heart monitor, lined up the two ends and pushed them together. It didn't even cross her mind that the cord she had just connected could potentially be from something other than the ECG machine. After all, she was a seasoned nurse who handled these machines every day, and they all seemed to have different connecting pins. Unbeknownst to her she had connected the ECG leads to the IV infusion pump. The cord from the infusion pump matched the size and shape of the six-pin ECG cord reasonably well. The similarity might not have been so dangerous had the infusion pump not been a battery powered portable model. Nurse K had no way to know she had been holding a live electrical wire, with the full electrical current of the IV pump. Connecting the cords delivered a direct shock to the little girl's chest, from which she could not be revived. Though it may be easy simply to claim that Nurse K should have paid closer attention to the situation, it would be an incomplete analysis. Even if she had been paying attention, would she have avoided this fateful error? We may never know. However, looking at this case through a human factors lens reveals a number of potential pitfalls to which Nurse K fell victim. The most glaring is the similarity between the ECG and IV pump cord. Despite the fact that they weren't perfect matches, they matched closely enough that one could connect the two. The most powerful HFE solution might be designing the two connections to have unique colors or shapes—the ECG cord round and the IV pump cord square, for example. Perhaps the device industry might be willing to subscribe to a set of standards such that all ECG cords have the same color and shape (ditto for pump cords). Another solution might be to have a warning label on the infusion pump's cord, alerting that it can deliver a direct and potentially fatal current. Even beyond the design of the devices, what other problems may have led to this child's death? Could the conditions of the room—the setup, the lighting, the ambient noise, or the nurse's workload—have played a role in the outcome? Maybe Nurse K wasn't used to seeing these particular device models in the same room. Maybe the demands of her job and the busy environment of a hospital floor were taking their toll. We'll never know for sure. But it is certain that the thoughtful application of HFE principles to this situation would have made it a safer environment. Reproduced with permission from Casey S. Set Phasers on Stun: And Other True Tales of Design, Technology, and Human Error. 2nd ed. Santa Barbara, CA: Aegean Publishing; 1998. |