Sleepy surgical residents impaired, study says

Surgical residents were more fatigued than expected, especially on night rotations, according to a new study. A quarter of their waking time, they were the equivalent of being legally drunk, the study said.

“Our fatigue levels were higher than we thought, but that allows us to focus on where the problems are likely to be,” Frank McCormick, a doctor from the Harvard Combined Orthopedic Residency Program and the lead researcher, said by telephone.

The study, published Monday in the journal Archives of Surgery, did not measure actual harm to patients from fatigue, just potential, he said.

“Overall, residents’ fatigue levels were predicted to increase their risk of medical error by 22% … compared with well-rested historical control subjects,” the researchers said.

The study looked at 27 orthopedic surgical residents at two large hospitals working various shifts. Researchers used a model called SAFTE (for sleep, activity, fatigue and taste effectiveness), the Fatigue Avoidance Schedule Tool and a wrist-worn gadget that monitors sleep and circadian rhythms. The surgeons also kept logs.

The amount of sleep ranged from 2.8 to 7.2 hours, with the mean of 5.3 hours. Based on the SAFTE model, the researchers said residents were functioning at less than 80% effectiveness because of fatigue nearly half of the time.

Further, they were functioning at less than 70% mental effectiveness -- the equivalent to a blood alcohol level of 0.08% -- 27% of the time. The researchers called that “critically impaired.”

Ways to lessen the risk of errors include altering schedules; at Massachusetts General Hospital, McCormick said, doctors are now on call overnight less frequently. Data are still being collected to see if that helps, he said.

In an accompanying editorial, Dr. Thomas F. Tracy Jr. noted that previous studies of fatigue had few good measurement tools. He called their determination of fatigue “not startling” but that its pervasiveness cannot be avoided.

Some of the other information the researchers found: overall, the residents read less than an hour a day; and a third of them drank two to three cups of coffee a day. We’re surprised that the rest had fewer.