ANESTHESIOLOGISTS have a personal and professional interest in sleep and fatigue. Whether as a metaphor for states of anesthesia 1or in reference to one's own level of arousal, the word “sleep” is a regular contributor to the vocabulary of anesthesiology. The article by Howard et al . 2in this issue of Anesthesiology reviews the negative influence of sleep deprivation. Projections of anesthesia work force and patient numbers continue to predict heavy workloads. Sleep deprivation causes stress, pessimism, and anger (http://www.sleepfoundation.org/nsaw/presskit.html). For anyone concerned with career sustainability, workload projections make the topic of sleep and fatigue a potentially frustrating read. Howard et al . 2avoid this pitfall by championing an evidence-based perspective on countermeasures that can be incorporated into one's practice and lifestyle. Sleep disorders medicine 3has been embraced and advanced by pulmonology, psychiatry, and neurology. Howard et al . 2help explain the developing recognition in anesthesiology about the important relation between sleep and health. Opposing views that sleep deprivation is harmless are tantamount to ignoring data on the relation between smoking and cardiopulmonary disease.
“Vigilance” is part of The American Society of Anesthesiologists’ logo and the negative impact of sleep deprivation on vigilance and performance is clear from driving safety data. Motor vehicle accidents in the United States are the fifth leading cause of death, a fact that has led the American Medical Association (AMA) to endorse research and education on the risks of driving while feeling sleepy. 4The negative influence of sleep deprivation is so strong 5that the US Congress directed the Federal Highway Administration to characterize fatigue among commercial drivers. 6These studies found that long-haul truck drivers had less sleep than needed for alertness, averaging 5.18 h in bed and 4.78 h of sleep per day. 6On 27 June 2002, the House Transportation and Infrastructure Committee held a hearing on “Approaches to Improving Highway Safety.” Testimony from Darrel Drobnich, Senior Director of Government and Transportation Affairs for the National Sleep Foundation, cited statistics from The National Highway Traffic Safety Administration (NHTSA). According to Drobnich's testimony, the NHTSA estimates that 100,000 police-reported crashes each year are the direct result of driver fatigue. These crashes cause 1,550 deaths and 71,000 injuries, as well as $12.5 billion in diminished productivity and property loss (http://www.sleepfoundation.org/PressArchives/drowsdrivetestimony.html). The loss of even 1 h of sleep associated with the shift to daylight savings time has been shown to increase the number of traffic accidents. 7Howard et al . 2effectively show that the sleep and performance relation would be irrelevant only if operating a motor vehicle required greater cognitive and psychomotor skills than the safe and effective delivery of anesthesia.
Medical education is negatively influenced by sleep deprivation. 8Sleep enhances cortical synaptic remodeling to facilitate the memory consolidation of the waking experience. 9Hippocampal cell discharge patterns reflecting behavioral experiences during waking consciousness are reactivated during rapid eye movement (REM) sleep, consistent with a REM sleep–dependent role in memory processing. 10,11Objective assessment of sleep and alertness among in-house medical staff found that interns averaged less than 5 h in bed and 3.67 h of sleep while on call. 12In a random sample of second-year residents, 25% reported being on call in the hospital more than 80 h per week and 10% reported sleep deprivation as a daily occurrence. 13These same residents commonly (70%) observed a colleague working in an impaired state that was most often (57%of the time) caused by lack of sleep. 13During the first postgraduate year, residents averaged 37.6 as the largest number of hours without sleep. 13Moderate sleep deprivation (17–19 h) causes impairment of cognitive and psychomotor performance equivalent to alcohol intoxication. 14The negative influence of sleep deprivation is so strong that under current Institutional Review Board guidelines, few institutions would approve a randomized, prospective, double-blind, controlled trial of sleep-deprived versus rested surgeons. 15One National Institutes of Health (NIH) database (http://www.crisp.cit.nih.gov/) shows that questionnaire and survey data play major roles in current NIH-funded studies on “Effects of Extended Work Hours on Intern Health & Safety” (caczeisler@rics.bwh.harvard.edu) and on “Work Conditions of Surgery Residents and Quality of Care” (mentzer@pop.uky.edu). These ongoing studies and the review by Howard et al . 2directly contradict minority opinions that sleep deprivation does not impair learning or performance. 16
Sleep deprivation significantly alters endocrine function, host defense, and autonomic control. In healthy young adults, sleep restriction to 4 h per night for 6 nights decreased carbohydrate tolerance, increased evening cortisol, and increased sympathetic tone. 17These endocrine changes are risk factors for development of obesity, insulin resistance, and hypertension. 17Preclinical studies show that within the first few days of sleep deprivation, normally sterile body tissues are invaded by endogenous pathogenic bacteria. 18Cytokines are known to alter central nervous system (CNS) control of sleep. 19There is evidence that bacterial and viral activation of spinal microglia and astrocytes can produce proinflammatory cytokines that amplify pain. 20There is an inverse relation between pain and sleep, 21and neural systems that evolved to regulate natural sleep states are preferentially involved in causing states of anesthesia. 22
One “hot button” topic not reviewed by Howard et al . 2is the Patient and Physician Safety and Protection Act. Representative John Conyers (D-Michigan) introduced this bill (HR 3236) in November 2001 to the 107th Congress. The HR 3236 bill proposes to reduce resident work shifts to not longer than 24 continuous h and to limit total weekly work to no more than 80 h. The bill can be viewed at http://www.thomas.loc.gov./ Sen. Jon Corzine (D-New Jersey) has introduced a companion bill to HR 3236. On June 11, 2002, while the Howard et al . 2manuscript was being reviewed, the Accreditation Council for Graduate Medical Education (ACGME) passed universal standards for resident work hours. The ACGME recommends resident work be limited to an average of 80 h per week and no more than 30 h at any one time. It also was recommended that residents be on call no more than every third night and have 1 in 7 days off from work. The complete recommendations are available in PDF format (http://www.acgme.org). In June 2002, the AMA backed the ACGME guidelines. M. Croasdale reports on the AMA position in the July 8/15, 2002 issue of American Medical News (http://www.ama-aasn.org/sci-pubs/amnews/pick_02/prsb0708.htm).
Howard et al . 2signal an opportunity for anesthesiology to take a leadership role in characterizing the effects of sleep restriction and sleep deprivation on patients undergoing anesthesia, on caregivers, and on trainees. The Patient and Physician Safety and Protection Act is championed by the 40,000-member American Medical Student Association (http://www.amsa.org). Many medical students and residents are well informed about sleep neurobiology and medicine. At the University of Michigan, for example, there is a combined graduate and undergraduate course, organized from the Department of Anesthesiology entitled “Sleep: Neurobiology, Medicine, and Society.” The course is team taught by faculty from departments of anesthesiology, neurology, psychiatry, pulmonary medicine, and psychology. The course attracts a significant number of allied health and premedical students. Considerable time is devoted to reviewing data on decrements in health and performance caused by overwork and sleep deprivation. All available evidence indicates that sleep, similar to breathing, is a fundamental biologic rhythm. Devaluing sleep is no longer compatible with attracting the best healthcare professionals to the specialty of anesthesiology.
