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Sleep Deprivation. Kirk Stucky Psy.D . ABPP 11-4-2011. Acknowledgments. Kay Taylor Ph.D. Julie Campe Michael Yassick Hurley Research Department Manfred Griffenstein Ph.D. ABPP My kids. Overview. What do we know? Effects on physician performance
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Sleep Deprivation Kirk StuckyPsy.D. ABPP 11-4-2011
Acknowledgments • Kay Taylor Ph.D. • Julie Campe • Michael Yassick • Hurley Research Department • Manfred Griffenstein Ph.D. ABPP • My kids
Overview • What do we know? • Effects on physician performance • Countermeasures for sleepiness and fatigue
The pot calling the kettle black • Graduate school - “I have to ace this test.” • Internship - “I need to see more cases.” • Residency - “I need to learn that procedure.” • Family - “I can’t ignore a crying baby.”
National Sleep Foundation (NSF) Trend in industrialized nations . . . Hours of sleep each night 23% reduction
Sleep cycle patterns in normal night of sleep; NREM: non-rapid eye movement; REM: rapid eye movement. Stage W (Awake) Stage N1 (Old NREM Stage 1)“Somnolence” or “drowsy sleep” • Aware of surroundings • Aware, drowsy • Myoclonic jerks • Loss of some muscle tone New sleep stage labeling(American Academy of Sleep Medicine, 2007) Stage N2 (Old NREM Stage 2) • Not aware of surroundings • Harder to awaken • Fragments of dreams • Eyes side to side slowly • Predominant NREM stage in adults • ~50% of sleep in adults Stage R (Old REM Stage) • Deepest stage of sleep • Delta wave/slow wave sleep • More difficult to arouse • Decreased muscle tone, metabolism • Restorative • Lowest metabolism Stage N3 (Old NREM Stages 3 & 4)“Deep” or “slow wave sleep” (SWS) 1 cycle ~90-110 minutes
New sleep stage labeling(American Academy of Sleep Medicine, 2007) Stage W (Awake) • Stage R (old REM Stage) • Active stage • Variable autonomic nervous system function with shifts between parasympathetic and sympathetic dominance • Increase in oxygen use • Rapid low-voltage EEG • Increase in cerebral blood flow • Memory storage and consolidation of learning • Large muscles immobilized but distal twitches • Rapid conjugate eye movement • Dream stage • ~20-25% of total sleep in adults Stage N1 (Old NREM Stage 1)“Somnolence” or “drowsy sleep” Stage N2 (Old NREM Stage 2) Stage N3 (Old NREM Stages 3 & 4)“Deep” or “slow wave sleep” (SWS) 1 cycle ~90-110 minutes
Regulation *Accreditation Council for Graduate Medical Education • July 2003 ACGME* instituted minimum duty hours for accredited programs in part due to impending threat of federal regulation • 80-hour weekly limit • 1 day in 7 free from all program responsibilities • Adequate rest between duties (10 hours) • No new patients after 24 hours • Limit on continuous duty to 24 hours + up to an added 6 hours for transfer of care and didactics • In-house moonlighting and home call counts toward duty hours
Why? . . . “.…the catalyst for dramatic changes to the work hours for physician-in-training did NOT come from evidence-based medicine … the landmark litigation over the death of a young New York woman, Libby Zion, was responsible for a landslide of events leading to the institution of work hour limitations for physician trainees…” Pulmonary Medicine 2005
Why? An 80-hour work week was imposed by the ACGME in July 2003 (following legislation by the United States Congress) to:
Financial considerations . . . “An estimated $1.8 billion per year was required to enact the 80 hours per week regulation, which can be extrapolated to $5 billion per year if the Harvard group’s recommendations were to be instituted.”
Drivers Sleepy drivers pose “a very serious risk.” An estimated 16% to 60% of road accidentsinvolve sleep deprivation. Restricting sleep by as little as 1-2 hours per night can lead to chronic sleep deprivation. Two-thirds of drowsy-driving-related crashes occur with drivers younger than 30 years of age. Sleep is NOT voluntary and a drowsy driver cannot tellwhen he/she is about to fall asleep.
Sleep loss, recovery sleep, and military performanceErgonomicsVolume 25, Issue 2, 1982, Pages 163 - 178 Abstract Ten experienced infantry soldiers completed a 9-day (216-hour) tactical defensive exercise, the aim of which was to determine whether soldiers are likely to remain militarily effective during a period of partial sleep loss following a period with no scheduled sleep at all. Assessments were made of shooting, vigilance, cognitive functioning, EEG activity and physical fitness. Results indicated that tasks with a vigilance and cognitive component began to deteriorate after one night without scheduled sleep. After 3 days (90 hours) with no scheduled (and very little unscheduled) sleep, 4hours block sleep had a marked beneficial effect upon performance. After a total of 12 hours sleep over 3 3/4 days (72 hours), performance had recovered (except for scores at 05.45 hours) from an approximate average level of 50 to 88% of control values. One and a quarter days (30hours) of rest, of which an average amount of 19 1/2 hours was spent asleep, eliminated any remaining decrement. EEG recordings indicated that on the six nights following total sleep loss there was an increased percentage of stage 4 sleep. Stage REM percentage remained virtually unchanged, except for the first night after total sleep loss, when there was 8% less. EEG results are discussed in relation to the work of other investigators.
Air traffic controllers to get more sleep under new FAA rules(4-17-11) WASHINGTON - The government said Sundayit is giving air traffic controllers an extra hour off between shifts so they don't doze off at work,a problem that stretches back decades. But officials rejected the remedy that sleep experts say would make a real difference: on-the-job napping."On my watch, controllers will not be paid to take naps. We're not going to allow that," Transportation Secretary Ray LaHood said. That's exactly the opposite of what scientists and the Federal Aviation Administration's own fatigue working group say is needed after 5 cases disclosed since late March of sleeping controllers. The latest one occurred just before 5 a.m. Saturday at a busy regional radar facility that handles high-altitude air traffic for much of Florida, portions of the Atlantic Ocean and the Caribbean Sea. Several other countries, including Germany and Japan, permit controllers to take sleeping breaks and they provide quiet rooms with cots for that purpose. "Given the body of scientific evidence, that decision clearly demonstrates that politics remain more important than public safety," said Bill Voss, president of the Flight Safety Foundation of Alexandria, Va. "People are concerned about a political backlash if they allow controllers to have rest periods in their work shifts the same way firefighters and trauma physicians do. "It has been an open secret in the FAA dating to at least the early 1990s that controllers sometimes sleep on the job. Toughest are the midnight shifts, which usually begin about 10 p.m. and end about 6 a.m. Scientists say it would be surprising if controllers didn't doze sometimes because they are trying to stay awake during the time of day when the body naturally craves sleep.
Airline pilots admit sleeping during flight(12-29-08) HONOLULU - The pilots on board a Go! airlines flight that overshot the Hilo airport last February have admitted they fell asleep in the cockpit while the plane was on autopilot. The pilots stopped responding to air traffic control communications about halfway through Flight 1002 from Honolulu to Hilo on Feb. 13, 2007, a recently released 11-page report by the National Transportation Safety Board said. The Air traffic controllers had other planes, including another go! jet and a Continental Airlines plane, attempt to contact the flight, but they were unsuccessful. Report says there was an 18-minute gap from about 9:40 until 9:58 a.m. when no one was able to communicate with Flight 1002 by radio. Instead of landing at Hilo as scheduled, Flight 1002 passed over Hilo International Airport at 21,000 feet and continued straight for nearly 30 miles past the airport over the open ocean. Phoenix-based Mesa Air Group, which owns go! airlines, fired both pilots after the incident.
Students - Effects on learning • Reduced ability to learn and decreased motivation to learn • Reduced participation in learning opportunities for those with sleep deprivation (Sawyer et al, 1999)
Are physicians different? • Myth: “I’m one of those people who only need 5 hours of sleep, so none of this applies to me.” • Fact: Individuals vary in their tolerance for sleep loss, but they are not able to accurately judge it themselves • Fact: The average human being requires 8 hours sleep to perform optimally • Fact: Getting less than 8 hours sleep starts a “sleep debt” that must eventually be paid off. • Fact: Environmental factors (e.g. boring lectures) may unmask but do not cause sleepiness. Source: American Academy of Sleep Medicine
Are physicians different? • Myth: “I’ve learned not to need as much sleep during my residency.” • Fact: Sleep needs are genetically determined and cannot be changed • Fact: Human beings do not adapt to getting less sleep than they need • Fact: Effort plus adequate rest result in optimal performance and task consistency
Definition • Chronic partial sleep loss –sleep duration of less than 5-6 hours for several consecutive nights • Common in residency with 20% reporting 5 hrs or less and 66% reporting 6 hours of less
Source: Wikicommons: http://en.wikipedia.org/wiki/File:Effects_of_sleep_deprivation.svg Accessed June 2, 2011
Neurocognitive • Sleep deprivation does not impact general intelligence; it impacts efficiency in thinking • Over learned skills can be protected as long as they are not monotonous. • Subjects who had gone a single night without sleep had recognizable declines in sustained attention skillsand working memory (Lim and Dinges, 2010)
Facts • Measurable declines in performance typically begin after15-16 hours of wakefulness • Fact: Period of lowest alertness after being up all night is between 6 am and 11 am (i.e., morning rounds) • Fact: Sleep-deprived individuals underestimate degree of tiredness and overestimate level of alertness
What tasks? What moderators? • Length and complexity of the task • Work paced tasks are affected more than tasks in which the person can self pace • Intraindividual variation –some are profoundly affected and others minimally affected by the same amount of sleep loss
Type of task • Paradoxical observations • In highly demanding tasks performance seems to be less affected by sleep deprivation • Monotonous or intrinsically less engaging tasks are more severely affected because greater top down control is required to sustain performance
Research • Individuals in the middle of the cohort with 24-30 hrs sleep loss had clinical performance similar to the lower 15% of the rested group (Picher and Huffcutt, 1996) • Two studies indicated that a 16-hour limit on resident hours increased alertness and reduced 1st year medication errors in the critical care setting. (Landrigan et al, 2004)
Studies on performance • Philibert, I (2005). Sleep loss and performance in residents and nonphysicians: A meta-analytic examination, Sleep, vol. 28, no. 11. • Effect of Sleep Deprivation was larger in nonphysicians that in physicians (-0.995 vs. -0.880) • Sleep loss of less than 30 hours reduced overall physician performance by 1 SD and clinical performance by 1.5 SD
Studies on performance • 1971 Friedman et al – found that residents who had been on call the night before made more errors reading an EKG than their rested colleagues • 1997 – 1999 Dawson and others – the reduction in performance after 24 hour sleep loss equated to the effects of a 0.1% BAL* (a level considered unfit for duty) • 2005 – Arnedt et al – heavy call rotation similar to 0.04 - 0.05% BAL* as measured by sustained attention, vigilance, and simulated driving tasks. Residents ability to judge degree of impairments was limited *BAL: Blood alcohol level
Safety • 50% greater risk of bloodborne pathogen exposure incidents in residents between 10pm and 6am (Parks, 2000) • Increased risk of traffic accidents post-call • 5% preventable incidents, 10% drug errors (Williamson, 1993) • Post-op surgical complication rates 45% higher if resident was post-call (Haynes et al, 1995)
Residents Memory consolidation Insight formation Impaired . . . “…the building blocks of learning, creativity, and scientific discovery.” Neurology 2005
What about physicians post residency? • Chronic sleep loss in house officers (attendings). One study 1985 showed reduced performance for “acute sleep loss.” • Sleep loss of 24-30 hours produced a - 0.986 reduction in aggregate performance, suggesting the possibility of performance decrements under the ACGME minimal standards • 60% of anesthesiologists report making fatigue-related errors (Gravenstein, 1990) • 3% of anesthesia incidents (Morris, 2000)
Research • Surgery: 20% more errors and 14% more time required to perform simulated laproscopy post call (Taffinder et al, 1998; Grantcharov,et al, 2001) • Internal Medicine: ECG interpretation errors in sleep-deprived interns (1994) • Pediatrics: Increased time to place an Arterial line (1989)
Summary of Studies • Clinical implications • Higher complication rate • Increased medical errors • Lower effectiveness on actual and simulated care tasks • Alertness is higher and errors are lower if continuous wakefulness is limited to 16 hours
The Cultural of medicine • Sleep is optional • The best physicians don’t need as much sleep • More dedicated doctors are sleep deprived • I only get sleepy during boring meetings and lectures. That does not mean I am sleep-deprived (denial?)
A time-honored tradition . . . . . Long work hours, demanding schedules Ideal model for learning and development of professionalism
Educational concerns . . . Work hour restrictions may negatively impact physician learning. “…in the midst of an ever increasingly complex knowledge base and system of care with ever increasing pressures on accountability for both safety and performance—there is now less time to accomplish these burgeoning goals…” Archives of Internal Medicine 2005
Concerns about the RRC policy • There may not be uniform benefits for residents from changes in duty hours • Unintended consequences – • Inadequate development of professionalism • Inconsistency in teams • Worse patient-physician communication skills • Decreased experience • Reduced hours may necessitate more years of training. Varying impact at different levels or types of training
Concerns about the RRC policy • Night float • Perhaps leads to more trouble sleeping • Mixed educational value
Concerns about the RRC policy • Reduced fatigue may be worthwhile if operative experience evens out over the course of training, but it may be problematic if the duty hour requirement significantly reduces the volume of experience • What amount of experience is needed during residency to achieve clinical competence?
Recent Focus: Impact of ACGME-mandated work hour reduction Medication errors Resident depression Resident injuries (motor vehicles crashes) 2008 Pediatrics122(2):250-258. Prospective cohort study in which residents from 3 large pediatric training programs provided daily reports of work hours and sleep as well as several ‘outcome’ variables. Although there was reduced reports of being burned out, there was NO change in rates of:
Recent Focus: Impact of ACGME-mandated work hour reduction continued Be sleep deprived (sleeping an average of 2.84 hours nightly) Obtain less than recommended amounts of recovery sleep 2007 Archives of Internal Medicine167(16):1738-44. Between 2003 and 2005, interns wore wristwatch activity monitors. Under the current duty-hour regulations, residents continued to:
Recent Focus: Impact of ACGME-mandated work hour reduction continued Levels of objective sleepiness remained unchanged Quality-of-life indexes deteriorated during the course of the ICU rotation 2007 Chest 131(6):1685-93. Examined effects of work-hour reduction on quality of life in ICU housestaff. Although subjective sleepiness improved, …
Criticisms • Requires a balance between protecting residents and caring for patients • Improved quality of life for residents may lead to better overall patient care but this has not been empirically established • Many studies rely exclusively on surveys and others are entirely retrospective • Interventions evaluated with variable and divergent measures • Need more assessment of objective outcomes rather than perceived outcomes
Warning signs for residents • Falling asleep during conferences, lectures, rounds • Feeling restless and irritable with staff, colleagues, family, friends • Rechecking work more often • Difficulty focusing or sustaining attention • Reduced concern about task, outcomes, or learning
Sleep hygiene • In bed and out of bed around the same time • Develop a predictable sleep routine • Don’t watch TV, play video games, or spend time on the computer to “get sleepy” • If you cannot fall asleep after 20 minutes get out of bed (classical conditioning) • Read in a comfortable chair • Read something tedious but necessary (board review questions) • Listen to relaxing music • Practice relaxed breathing, meditation, biofeedback, prayer, etc. (find out what works for you)