Medical staff working the night shift: can naps help?

Napping at night may benefit both health professionals and their patients elivering medical care is a 24-hour business that inevitably involves working the night shift. However, night shift requires the health professional to work when the body' s clock (circadian system) demands sleep. Added to this is the problem of " sleep debt " , arising from both prolonged prior wakefulness on the first night shift and cumulative sleep debt after several nights' work and repeated unsatisfactory daytime sleeps. A further aggravation, particularly for trainee medical staff in teaching hospitals, has been the demand for excessive work hours across the working week. As has been dramatically shown in recent well controlled studies, the net result of this assault on the sleep of health professionals can be impaired patient safety, 1 and the health and safety of health professionals themselves. 2 The good news is that health organisations and regulators are beginning to treat the matter seriously. In Australia, the United States and Europe, work hours of medical staff have recently been shortened by government regulation, and bodies such as the Australian Medical Association and professional colleges are advising their members on strategies to improve their sleep health and thus work safety. A recent publication prepared by the Royal College of Physicians (London) (RCP), Working the night shift: preparation, survival and recovery. A guide for junior doctors, is an excellent example. 3 One proposed countermeasure for excessive sleepiness is the use of strategically placed naps both before and during the night shift. But does napping either before or during the night shift reduce sleepiness and improve performance , and, if so, how practical is it? There are two important, independent mechanisms of sleep and sleepiness that hold the key to these questions. 4 Probably the more potent mechanism impairing night-shift alertness is the circadian system. For most individuals, even those working permanent night shift, the circadian system is in sleep mode during the night. This causes slowed reactions, increased feelings of fatigue, impaired concentration, and increased sleep propensity. The second important mechanism affecting night-time alertness is homeostatic sleep drive. This increases in intensity the longer we are awake and, like appetite which is sated by eating, homeostatic sleep drive is reduced by sleeping. If the first night shift starts at midnight following a normal wake time at about 8 am, about 16 hours of wake sleep debt has already been accrued …