The Poka-Yoke in a Surgical Pathology Laboratory

In the laboratory it is accessioned, grossed, and processed into glass slides for review by the pathologist. He reviews the slides and produces an expertise that is signed out and delivered to the clinicain in electronic or hardcopy version. All the processes and resources within the surgical pathology laboratory are centered on producing a final surgical pathology report and each step in production adds value to the final product.

Medical errors are classified in terms of clinical outcomes, such as harm. Errors may be classified into near-miss events, no-harm events, and sentinel events. A near-miss event is an event, action, or process that requires correction, or an error with potential serious consequences may occur. The identification of near-miss events allows for process redesign to eliminate potential sources of error. A sentinel event is associated with clinical harm.

The most feared error in the surgical pathology laboratory is misidentification which can occur in any step during the multiple handling of specimens, blocks, slides and reports in the process of generating a final surgical pathology report. Root cause analysis has shown that most detected surgical pathology errors are associated with multiple latent factors. Survey methods also showed that independent of the diagnostic abilities of the pathologist, errors in the technical portions of the laboratory contribute to catastrophic patient injury

In medicine, most errors are caused by a combination of active errors and underlying latent conditions that contribute to active errors. Active errors occur as a result of human failures in unsafe environments in which underlying factors contribute to the potential for error. The lack of training, high workload volume, and hectic pace are examples of latent conditions that contribute to active human failures.

A poka-yoke is any mechanism that helps an equipment operator avoid mistakes. The concept was formalised and the term adopted by Shigeo Shingo as part of the Toyota Production System where a poka-yoke has a role in eliminating product defects by preventing, correcting, or drawing attention to human errors as they occur.

The use of poka-yoke in the surgical pathology laboratory can reduce misindentification with minimal costs for implementation. One of the best applications of poka-yoke is in teaching staff when to avoid working in batches. For example, the presence of a batch of multiple labeled slides and blocks from different patients at the microtome station increases the likelihood of switched specimens. The same may occur when leftover labeled tissue cassettes are not discarded prior to beginning work on another specimen. Working in batches may decrease takt time but the increase in the likelihood of misidentification must also be considered. Group discussions by managers and staff about possible areas of error can lead to suggestions on poka-yoke procedures to decrease misidentification errors. These are especially useful as both regular meetings and as part of error analysis. The cultural changes ( e.g. blame-free environment ), system changes and shifting the investigation to organizational and technical factors away from the individual frontline worker can also improve the safety and reduce the possibility of the most feared error in the surgical pathology laboratory.