One of the rights of passage in medical training is to spend months prowling hospital corridors overworked and overtired. Recent reforms have tried to change that, but new and stricter rules still permit working a medical resident for thirty hours without so much as a nap. So how good is the judgment of an exhausted doctor?

About as good as the judgment of someone who’s been drinking, according to a pilot study by Brown Medical School professors. The study found that medical residents performed at least as badly when they were sleep deprived as when they were moderately intoxicated.

In a test that simulated driving a car, nineteen pediatric residents were tested after a month of heavy night-call duty and again after they were well rested but had a blood-alcohol concentration of .04 percent to .06 percent. Researchers concluded that participants had as much or more trouble maintaining lane position and constant speed when they were tired from working as when they were tipsy.

A concentration of .04 percent translates into two drinks in an hour for a woman and two to three for a man, says Todd Arnedt, assistant professor of psychiatry and human behavior, who led the study with Judith Owens ’77, ’80 M.D., an associate professor of pediatrics. Although the level is below the legal limit for driving (.08 percent in most states), it’s high enough, Owens says, to make sleep deprivation a hazard for doctors and a cause for alarm in patients. “Would you want your doctor operating on you after drinking three beers?” she asks.

Examining driving patterns was no accident. Owens herself totaled her car on the morning after her last night on call as a resident in the early 1980s, and residents have been known to fall asleep at the wheel after an on-call night. In fact, Owens recommends that sleepy residents not drive at all, or, if they have no choice, that they first chase a cup of coffee with a twenty-minute nap.

The study, which was part of a larger investigation into how sleep loss affects medical residents, was presented at a recent meeting of the Pediatric Academic Societies. In the fall Owens and Arnedt plan to analyze the rest of their data for other potential effects of fatigue on doctors. Focus groups with residents already suggest that their empathy toward their patients may suffer.

“Residents would say things like, ‘The patient is my enemy because that’s the only thing between me and sleep,’ ” Owens relates. “I’ve been there. I know exactly what that’s like.”