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Why Surgeons Make Catastrophic Mistakes

A new analysis codes the reasons behind mistakes like operating on the wrong leg, or leaving a tool behind in a person's body.
(Photo: Dmitry Kalinovsky/Shutterstock)

(Photo: Dmitry Kalinovsky/Shutterstock)

You've probably heard about the woman who had a sponge left in her body from a hysterectomy four years ago, or the man whose surgeon accidentally implanted a kidney on his left side, instead of his right.

One recent estimate found that catastrophic mistakes—including implanting the wrong thing, or performing the wrong procedure—occur in one out of every 12,000 surgeries in the United States. To figure out why, a team of researchers from the Mayo Clinic in Rochester, Minnesota, decided to analyze botched surgeries at their own clinic in the way investigators do military airplane accidents.*

The researchers used an aviation accident-investigation tool called the Human Factors Analysis and Classification System, which helped them pinpoint which human errors are most common in surgeries gone wrong. Their work suggests hospitals should look for ways to reduce the mental lifting that surgery team members must do during a procedure, the researchers write in a paper published last week in the journal Surgery. That's in addition to the "systems engineering"-type of solutions that hospitals have recently used to reduce errors, such as installing computer systems that automatically track surgical sponges' whereabouts—and alert people when sponges get left behind in the body. (Sponges are the most common item left behind after surgeries.)

Serious surgical accidents tend to involve many human failures. The average surgery saw nine separate missteps.

To conduct the study, Mayo researchers collected Human Factors Analysis and Classification System data from debriefings that surgery teams held after catastrophic mistakes. The HFACS checklist includes 161 human errors, grouped into specific categories, that can happen during a procedure. The researchers categorized the causes of 69 botched surgeries this way.

Serious surgical accidents tend to involve many human failures, the researchers found. The average surgery saw nine separate missteps. The most common problems they found fell into the category of the mental conditions of the surgeons and nurses, including overconfidence, and focusing too much on a minute detail and consequently losing sight of the big picture. Another common problem category: "decision errors," like failing to understand the risks of a procedure, or mixing up procedures, tests, and medications that perhaps have similar names. Meanwhile, oversight factors, such as a lack of accountability, and organizational factors—say, a lack of funding—were less likely to be cited as reasons for catastrophic surgery mistakes.

The results suggest surgery team members are cognitively overloaded, the researchers write. That's why they're making these mental mistakes. More complicated procedures and technology, and patients with more complicated health problems, all tax surgeons and nurses, other research has found. That can lead people to perform procedures incorrectly, even when they don't intend to.

In their paper, the researchers don't offer many specific suggestions for improvement, but they did note that lightening the mental load might involve scheduling fewer procedures for staffers, or giving surgical team members more independence, so they don't have to check everything with one overworked supervisor. Fixing human mistakes in surgery, it turns out, likely means making things easier for the humans involved.


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*UPDATE — June 15, 2015: This article has been updated to reflect the correct location of the Mayo Clinic.