Patients have no need to fear sleepy surgeons, study finds


The pager goes off at 2 a.m., alerting the on-call surgeon that a patient needs immediate care. The situation is resolved a few hours later, and she’s able to get a little more shut-eye before her regularly scheduled patients are wheeled into the operating room.

A new study in the New England Journal of Medicine finds that in situations like these, patients who went under the knife the morning after experienced a meaningful complication — or even death — 22.2% of the time.

Other times, when those same surgeons performed the same procedures when they hadn’t worked the night before, the rate of complications and deaths was 22.4%, the study found.


That’s right: For these surgeons, having to wake up and work in the middle of the night did not affect their performance the next day.

Most of us probably would have trouble staying awake in a meeting or focusing on an important assignment if we were roused from sleep in the wee hours of the morning. But surgeons are different.

“Acute sleep deprivation can impair mood, cognitive performance, and psychomotor function,” the study authors wrote. However, in their analysis of procedures performed on nearly 40,000 patients, “we did not find any significant difference in outcomes.”

The researchers — from the University of Toronto and Mount Sinai Hospital, also in Toronto — combed through health databases for the entire province of Ontario to find patients who had any of the following elective procedures between 2007 and 2011: coronary-artery bypass grafting; spinal surgery; removal of the gall bladder, uterus or part of the lung or colon; gastric bypass; craniotomy; coronary angioplasty; knee or hip replacement; or repair of a fractured hip.

They also searched through billing databases to see whether any of the surgeons who performed these procedures had worked between midnight and 7 a.m. the same day. (Early-morning rounds in the hospital didn’t count.)

The researchers identified 19,489 patients who were operated on by 1,448 surgeons in 147 hospitals who had treated someone else in the early-morning hours. Each of these “post-midnight” cases was matched with a “control” case that involved the same surgeon performing the same procedure on a patient of roughly the same age (give or take five years) on a day when they were more fully rested.


The lack of sleep made no difference to the surgeons — 1.1% of patients died in both the post-midnight group and the control group. The median amount of time needed to complete the surgeries was also identical for both groups (2.6 hours), as was the number of days spent in the hospital (three). The rate of complications was nearly the same (18.1% for the post-midnight patients and 18.2% for the control patients).

Patients in the post-midnight group were slightly less likely than their counterparts to require readmission to the hospital within 30 days of their procedure, but the difference in readmission rate — 6.6% vs. 7.1% — was small enough that it could have been due to chance, according to the study.

The researchers sliced and diced the data and found that lack of sleep didn’t matter for older surgeons or for younger ones. Nor did it matter for surgeons who worked at an academic hospital (where they are assisted by medical students and residents) or for those in private practice.

The only significant difference the researchers could find was that when surgeons treated two or more people in the post-midnight period, their patients were 14% more likely to have complications compared with patients in the control group. However, the odds of death and of hospital readmission were statistically equivalent.

How is it possible for surgeons to perform so well after working in the middle of the night? Perhaps they exercise good judgment and cancel or reassign their patients “if they feel too fatigued to perform surgery safely,” the study authors wrote. They might even be pro-active and schedule a light load for days when they are post-call.

The results suggest there’s no need to impose new work-hour limits on doctors in the name of patient safety, the study authors concluded. Still, they added, “it remains important for physicians to critically assess the effects of all sources of fatigue on their individual ability to treat patients and self-regulate their practices appropriately.”


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