Study shows naps improve residents' alertness on call

Even just 40 minutes more sleep while on in-hospital call significantly improves medical residents' alertness, according to a new study. Authors said that suggests it might be possible to extend residents' call periods beyond the 30-hour limit if naps are included.

Researchers at the University of Chicago spent a year studying 38 first-year residents' fatigue after 30 hours on call. Internal medicine interns were assigned to a nap schedule for two weeks of each month. During the nap schedule, they could sign over their pagers to a night-float resident from midnight to 7 a.m. so they could finish their work and sleep. During the other two weeks, they worked a standard schedule and were not allowed to sign over their pagers.

Researchers found that interns on the nap schedule slept an average of 185 minutes -- 41 minutes longer than on the standard schedule. That resulted even though the majority of interns retained responsibility for the patients they had admitted that day, only forwarding pages for the 30 or more patients they were covering for other interns.

The interns also reported less fatigue, according to the study published in the June 6 Annals of Internal Medicine.

Vineet Arora, MD, lead author of the study and an instructor of medicine at the University of Chicago, said that since the research project was finished, all interns on the general medicine service there are encouraged to sign over their pagers for night-float coverage after midnight.

Matt Glathar, MD, an intern at the University of Chicago just coming off overnight call, estimates he got three hours of sleep because of changes instituted.

"It makes a world of difference," said Dr. Glathar, who keeps the six or so patients he admits to the hospital on a given day, while signing over the rest. "You're considerably more functional and efficient in the morning."

Naps not only make the 30-hour call period more manageable for residents, Dr. Arora said, they also could make even longer shifts possible to help reduce the number of patient transfers, which are a common source for medical errors.

Holly Humphrey, MD, dean for medical education at the university's Pritzker School of Medicine and the University of Chicago Hospitals, and a co-author on the paper, said such studies should help the Accreditation Council for Graduate Medical Education refine resident duty-hour regulations. "I'm hoping the ACGME might be informed by this kind of work so that we may, as a profession, craft more appropriate policies to promote safety for patients and good health and safety for physicians," she said.

Some against longer hours

Bertrand M. Bell, MD, a professor at the Albert Einstein College of Medicine in New York and chair of the Bell Commission, which drove New York to become the first state to regulate resident work hours, cautioned against using naps as a way to extend residents' hours. "Napping implies you're already sleep-deprived ... that [you] are not working a rational work schedule," he said.

Todd Swick, MD, section chief over sleep medicine at the Methodist Neurological Institute in Houston, said the study confirmed that interns are sleep-deprived despite national limits on their hours and showed that when they do sleep at the hospital, they don't sleep well.

According to the study, interns on the standard schedule were inefficient sleepers, sleeping only 73% of the time they were in bed. That time improved to 80% when they signed their patients over to a night-float resident.

"You're on call, you're worried about being paged, so you're having fragmented sleep and your sleep efficiency drops," he said. "You can't have a doctor who is committed to patient care sleep in the hospital and not feel guilty about not taking care of patients. If you make them go home, they're forced to disconnect and get the restorative sleep that they need."

Instead of trying to use naps to lengthen residents' hours, Dr. Swick said, hospitals should encourage naps for residents' well-being.

"Let them have the opportunity to rest at some point in the morning, so the rest of their day can be salvaged," he said.

Gregory Belenky, MD, director of the Sleep and Performance Research Institute at Washington State University in Spokane, agreed that the study shouldn't be used to pursue longer hours for residents.

"What you can take away from this is a simple straightforward conclusion," Dr. Belenky said. "Protected sleep time is superior to unprotected sleep, even when residents don't sign over all of their patients. All programs should make arrangements to have some protected sleep time but don't go further to allow the relaxation of current ACGME requirements."