Routinely, obstetricians are scheduled for on-call shifts that range from 24 hours to 60 hours— sometimes, even longer.1,2 Is there a positive side to this practice? There can be: An extended on-call shift maximizes the likelihood that an OB will be available to provide personalized care to her (his) patient from the beginning of active labor through delivery, and most clinicians and patients believe that such continuity enhances care and outcomes.
But there is also a major disadvantage to the extended on-call shift: It may require the OB to be not only awake, but alert, for a long period—more than 24 hours, on occasion.
Sleep research shows that going 24 hours or longer without sleep has adverse effects on alertness, decision-making, task performance, and emotional function. The question is: Does an extended period of wakefulness impair the decision-making and surgical proficiency of OBs?
Extended-duty hours impair performance…
- The risk of an auto crash more than doubles right after an intern’s extended-duty shift.
It’s long been recognized in the transportation industry that extended time at work—that is, beyond the typical length of a work day—without sleep is associated with an increase in the rate of accidents.3 Consequently, in those occupations, extended-duty shifts are restricted by law to reduce the risk of a crash.
Interesting research has extended these observations to examine motor vehicle crashes involving physicians who have just experienced prolonged wakefulness as a result of extended-duty hours. Barger and colleagues used Web-based methods to survey 2,737 medical interns about the relationship among motor vehicle crashes, “near misses,” and work shifts that were less than 24 hours or longer than 24 hours. Using the number of motor vehicle crashes that occurred after shifts of less than 24 hours as the referent category, shifts longer than 24 hours were associated with a 2.3-fold increase in the risk of a crash immediately after the extended shift (95% confidence interval, 1.6–3.3).4
There is more: Extended-duty hours have been reported to increase dangerous driving behaviors among physicians and nurses in a simulated driving test: Clinicians completing a night shift often drove off the road or into oncoming traffic.5
If an extended shift can cause deterioration in driving performance, it might also affect how well a clinician performs standardized surgical tasks. In a preliminary study, needlestick injuries were more common among physicians toward the end of an extended-duty shift and during a nighttime shift.6 More research is needed to directly address what impact fatigue has on surgical tasks.
…and decision-making
- Interns on an extended-duty shift showed EEG signs of early sleep.
Lockley and colleagues performed a randomized study that compared the effect of extended-duty work hours and of reduced-duty work hours on how well medical interns performed in an intensive care unit.7 Interns were randomly assigned to a traditional, every-third-night, on-call schedule (work every weekday and, in addition, work all night every third night and every third weekend day) or a reduced-duty–hours schedule (take a day off after working an evening–night shift). The average workweek was 85 hours for an extended-duty–hours intern and 65 hours for a reduced-duty–hours intern.
One endpoint of the study was the rate at which continuous ambulatory EEG monitoring demonstrated intrusion of episodes of slow-rolling eye movements lasting longer than 30 seconds into wakefulness during work hours. (These movements, a measure of reduced attentiveness, are often observed at the beginning of a sleep cycle.) Interns working extended-duty hours had 5.5 episodes of slow-rolling eye movements for every overnight shift; subjects working reduced–duty hours had 2.6 episodes for every overnight shift.7
A second endpoint was the rate of serious decision-making errors in the two groups. Interns on an extended shift were prospectively observed to make 193 serious errors for every 1,000 patient-days worked—compared with 158 serious errors for every 1,000 patient-days worked among interns on reduced-duty hours (P <.001).8
There is a humorous, but horrifying, footnote to this study: Interns standing with their team at attending rounds sometimes demonstrated an EEG pattern consistent with sleep.
Caffeine? It may help
Without belaboring the obvious, clinicians who work an extended-hour shift have used coffee or other caffeinated beverages to help them remain alert. Research shows that caffeine may help fend off detrimental cognitive effects resulting from a long interval of wakefulness.9,10