Editorial Views  |   November 2002
Fact and Fantasy about Sleep and Anesthesiology
Author Affiliations & Notes
  • Ralph Lydic, Ph.D.
  • *Bert La Du Professor and Associate Chair for Research, Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan.
Article Information
Editorial Views
Editorial Views   |   November 2002
Fact and Fantasy about Sleep and Anesthesiology
Anesthesiology 11 2002, Vol.97, 1050-1051. doi:
Anesthesiology 11 2002, Vol.97, 1050-1051. doi:
ANESTHESIOLOGISTS have a personal and professional interest in sleep and fatigue. Whether as a metaphor for states of anesthesia 1 or 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  . 2 in 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 (). For anyone concerned with career sustainability, workload projections make the topic of sleep and fatigue a potentially frustrating read. Howard et al  . 2 avoid this pitfall by championing an evidence-based perspective on countermeasures that can be incorporated into one's practice and lifestyle. Sleep disorders medicine 3 has been embraced and advanced by pulmonology, psychiatry, and neurology. Howard et al  . 2 help 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. 4 The negative influence of sleep deprivation is so strong 5 that the US Congress directed the Federal Highway Administration to characterize fatigue among commercial drivers. 6 These 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. 6 On 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 (). 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. 7 Howard et al  . 2 effectively 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. 8 Sleep enhances cortical synaptic remodeling to facilitate the memory consolidation of the waking experience. 9 Hippocampal 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. 10,11 Objective 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. 12 In 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. 13 These 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. 13 During the first postgraduate year, residents averaged 37.6 as the largest number of hours without sleep. 13 Moderate sleep deprivation (17–19 h) causes impairment of cognitive and psychomotor performance equivalent to alcohol intoxication. 14 The 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. 15 One National Institutes of Health (NIH) database () shows that questionnaire and survey data play major roles in current NIH-funded studies on “Effects of Extended Work Hours on Intern Health & Safety” () and on “Work Conditions of Surgery Residents and Quality of Care” (). These ongoing studies and the review by Howard et al  . 2 directly 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. 17 These endocrine changes are risk factors for development of obesity, insulin resistance, and hypertension. 17 Preclinical studies show that within the first few days of sleep deprivation, normally sterile body tissues are invaded by endogenous pathogenic bacteria. 18 Cytokines are known to alter central nervous system (CNS) control of sleep. 19 There is evidence that bacterial and viral activation of spinal microglia and astrocytes can produce proinflammatory cytokines that amplify pain. 20 There is an inverse relation between pain and sleep, 21 and 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  . 2 is 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 ./ Sen. Jon Corzine (D-New Jersey) has introduced a companion bill to HR 3236. On June 11, 2002, while the Howard et al  . 2 manuscript 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 (). 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 (sci-pubs/amnews/pick_02/prsb0708.htm).
Howard et al  . 2 signal 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 (). 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.
Shafer A: Metaphor and anesthesia. A nesthesiology 1995; 83: 1331–42Shafer, A
Howard SK, Rosekind MR, Katz JD, Berry AJ: Fatigue in Anesthesia: Implications and strategies for patient and provider safety. A nesthesiology 2002; 97: 1281–94Howard, SK Rosekind, MR Katz, JD Berry, AJ
Kryger MH, Roth T, Dement WC: Principles and Practice of Sleep Medicine, 3rd edition. Philadelphia, WB Saunders, 2000, pp 1–1067
Lyznicki JM, Doege TC, Davis RM, Williams MA: Sleepiness, driving, and motor vehicle crashes. JAMA 1998; 279: 1908–13Lyznicki, JM Doege, TC Davis, RM Williams, MA
Mitler MM, Carskadon MA, Czeisler CA, Dement WC, Dinges DF, Graeber RC: Catastrophes, sleep and public policy: Consensus report. Sleep 1988; 17: 84–93Mitler, MM Carskadon, MA Czeisler, CA Dement, WC Dinges, DF Graeber, RC
Mitler MM, Miller JC, Lipsitz JJ, Walsh JK, Wylie CD: The sleep of long-haul truck drivers. New Engl J Med 1997; 337: 755–61Mitler, MM Miller, JC Lipsitz, JJ Walsh, JK Wylie, CD
Coren S: Daylight savings time and traffic accidents. New Engl J Med 1996; 334: 924Coren, S
Owens JA, Veasey SC, Rosen RC: Physician, heal thyself: Sleep, fatigue, and medical education. Sleep 2001; 24: 493–5Owens, JA Veasey, SC Rosen, RC
Frank MG, Issa NP, Stryker MP: Sleep enhances plasticity in the developing visual cortex. Neuron 2001; 30: 275–87Frank, MG Issa, NP Stryker, MP
Louie K, Wilson MA: Temporally structured replay of awake hippocampal ensemble activity during rapid eye movement sleep. Neuron 2001; 29: 145–56Louie, K Wilson, MA
Stickgold R, Hobson JA, Fosse R, Fosse M: Sleep, learning, and dreams: Off-line memory reprocessing. Science 2001; 294: 1052–7Stickgold, R Hobson, JA Fosse, R Fosse, M
Richardson GS, Wyatt JK, Sullivan JP, Orav EJ, Ward AE, Wolf MA, Czeisler CA: Objective assessment of sleep and alertness in medical house staff and the impact of protected time for sleep. Sleep 1996; 19: 718–26Richardson, GS Wyatt, JK Sullivan, JP Orav, EJ Ward, AE Wolf, MA Czeisler, CA
Daugherty SR, Balwin DC, Rowley BD: Learning, satisfaction, and mistreatment during medical internship: A national survey of working conditions. JAMA 1998; 279: 1194–9Daugherty, SR Balwin, DC Rowley, BD
Williamson AM, Feyer A-M: Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication. Occup Environ Med 2000; 57: 49–655Williamson, AM Feyer, A-M
Altschuler EL: Prospective, randomised trial of sleep deprived versus rested surgeons. Lancet 1999; 353: 501Altschuler, EL
Brown BJ, Van Susteren T, Onsager DR, Simpson D, Salaymeh B, Condon RE: Influence of sleep deprivation on learning among surgical house staff and medical students. Surgery 1994; 115: 604–10Brown, BJ Van Susteren, T Onsager, DR Simpson, D Salaymeh, B Condon, RE
Spiegel K, Leproult R, Van Cauter E: Impact of sleep debt on metabolic and endocrine function. Lancet 1999; 354: 1435–9Spiegel, K Leproult, R Van Cauter, E
Everson CA, Toth LA: Systemic bacterial invasion induced by sleep deprivation. Am J Physiol 2000; 278: R905–16Everson, CA Toth, LA
Krueger JM, Fang J: Cytokines and sleep regulation, Handbook of Behavioral State Control: Cellular and Molecular Mechanisms. Edited by Lydic R, Baghdoyan HA. Boca Raton, CRC Press, 1999, pp 609–22
Watkins LR, Milligan ED, Maier SF: Glial activation: A driving force for pathological pain. Trends Neurosci 2001; 24: 450–5Watkins, LR Milligan, ED Maier, SF
Lydic R: Pain: A bridge linking anesthesiology and sleep research. Sleep 2001; 24: 10–2Lydic, R
Lydic R, Baghdoyan HA: Cholinergic contributions to the control of consciousness, Anesthesia: Biologic Foundations. Edited by Yaksh TL, Lynch C, Zapol WM, Maze M, Biebuyck JF, Saidman LJ. Philadelphia, Lippincott–Raven, 1997, pp 433–50