Patient Safety and Quality

Coverage that allows interns to nap during extended shifts can increase their sleep time and decrease fatigue

Fatigue among first-year residents (interns) has been linked to needle sticks and cuts on the job and medical errors that can harm patients. As a result, interns are now limited to working 80 hours per week over a 4-week period. However, extended work shifts up to 30 consecutive hours are still allowed. Naps can increase sleep time and reduce the fatigue of interns during extended shifts, concludes a study supported in part by the Agency for Healthcare Research and Quality (HS10597).

Researchers assessed the effects of taking a nap while on-call at night on sleep and fatigue of 38 internal medicine interns. For 2 weeks during a month-long rotation, other residents provided on-demand nap coverage for on-call interns from midnight to 7 a.m., so that they could finish their work and take a nap. The other 2 weeks of the month were a standard schedule. During the entire month, interns wore an activity monitor to measure sleep time, record on-call and post-call fatigue, and record nap coverage.

Interns slept 41 more minutes on the nap schedule than the standard schedule (185 minutes vs. 144 minutes), a modest increase. When interns with the nap schedule used coverage, they received 68 more minutes of sleep (210 vs. 142 minutes). Despite these small increases in sleep, interns reported less overall fatigue while on the nap schedule than while on the standard schedule (1.74 vs. 2.26 on a 7-point scale with 7 being the most tired).

Fatigue on the post-call day with the nap schedule was lower by nearly 1 point (2.23 vs. 3.16) than the standard schedule, a potentially clinically significant difference. However, interns typically used shorter naps than their coverage allowed due to their desire to care for their patients and concerns about discontinuity of care by covering residents. An alternative to shorter work shifts may be use of an extended long shift with a nap, suggest the researchers.

See "The effects of on-duty napping on intern sleep time and fatigue," by Vineet Arora, M.D., M.A., Carrie Dunphy, B.S., Vivian Y. Chang, B.A., and others in the June 2006 Annals of Internal Medicine 144(11), pp. 792-798.

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