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Circadian Rhythms and Shift Work 1 Vicken Y. Totten MD: Vicken Y. Totten MD: Emergency Physician Emergency Physician and Career-long Shift Worker and Career-long.

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Presentation on theme: "Circadian Rhythms and Shift Work 1 Vicken Y. Totten MD: Vicken Y. Totten MD: Emergency Physician Emergency Physician and Career-long Shift Worker and Career-long."— Presentation transcript:

1 Circadian Rhythms and Shift Work 1 Vicken Y. Totten MD: Vicken Y. Totten MD: Emergency Physician Emergency Physician and Career-long Shift Worker and Career-long Shift Worker

2 Circadian Rhythms and Shift Work 2

3 3 SLEEP in literature Sleep, that knits the ravell'd sleave of care, Sleep, that knits the ravell'd sleave of care, The death of each day's life, sore labour's bath, The death of each day's life, sore labour's bath, Balm of hurt minds, great nature's second course, Balm of hurt minds, great nature's second course, Chief nourisher in life's feast. Chief nourisher in life's feast. - Shakespeare, Macbeth, Act II, Scene I- Shakespeare, Macbeth, Act II, Scene I

4 Circadian Rhythms and Shift Work 4

5 5 Goals and Objectives: Describe normal sleep structure Describe normal sleep structure Discuss Circadian Rhythm Disorders Discuss Circadian Rhythm Disorders Describe types of shift work patterns Describe types of shift work patterns Offer concrete shiftwork suggestions Offer concrete shiftwork suggestions Provide a resource list Provide a resource list

6 Circadian Rhythms and Shift Work 6 Biologic Rhythm Control Innate rhythms poly-genetically determined Innate rhythms poly-genetically determined Master clock in suprachiasmatic nucleus of the rostro-ventral hypothalamus. Master clock in suprachiasmatic nucleus of the rostro-ventral hypothalamus. Mediated by light/dark cycles via cryptopsin receptors in retina, skin and possibly pituitary Mediated by light/dark cycles via cryptopsin receptors in retina, skin and possibly pituitary Humans: Day = alert / Night = sleep. Humans: Day = alert / Night = sleep.

7 Circadian Rhythms and Shift Work 7 Biologic rhythms All body systems change rhythmically All body systems change rhythmically 90 minute alertness cycle 90 minute alertness cycle Monthly fertility cycle Monthly fertility cycle Sleep/wake generally hour cycle Sleep/wake generally hour cycle

8 Circadian Rhythms and Shift Work 8

9 9 Rhythm disorders Normally, biologic cycles kept in synch by signal substances such as melatonin, cortisol and others Normally, biologic cycles kept in synch by signal substances such as melatonin, cortisol and others Disruption in these systems have profound health implications. Disruption in these systems have profound health implications. Disrupted by both internal and external signals Disrupted by both internal and external signals Cycles re-synchronize at different rates Cycles re-synchronize at different rates

10 Circadian Rhythms and Shift Work 10 Circadian disruption De-synchronization of innate biologic / circadian cycles. De-synchronization of innate biologic / circadian cycles. Chronically in shiftwork and briefly from jetlag. Chronically in shiftwork and briefly from jetlag. Medicine is far behind industry in recognizing the implications of shift work Medicine is far behind industry in recognizing the implications of shift work

11 Circadian Rhythms and Shift Work 11 Causes of circadian rhythm disorders Genetics Genetics Medications Medications Pregnancy Pregnancy Shift work Shift work time zone changes time zone changes

12 Circadian Rhythms and Shift Work 12 Normal Sleep Architecture: Stages of sleep Non-REM (NREM) sleep - Stages I-IV brain idle, body mobile Non-REM (NREM) sleep - Stages I-IV brain idle, body mobile REM - Body paralyzed, Brain active (more metabolically active than during waking) REM - Body paralyzed, Brain active (more metabolically active than during waking)

13 Circadian Rhythms and Shift Work 13 Stage 1 - transition period. Normally 10 minutes. Eyes rove. Normally 10 minutes. Eyes rove. Most people awakened during Stage 1 claim they are not asleep. Most people awakened during Stage 1 claim they are not asleep. “Micro-Sleeps” “Micro-Sleeps” Driving while fatigued Driving while fatigued

14 Circadian Rhythms and Shift Work 14 Stage 2 - Deeper, fewer eye movements. Shallowest restorative sleep. Shallowest restorative sleep. About half of adult sleep in Stage 2. About half of adult sleep in Stage min. before progressing to next stage. 20 min. before progressing to next stage.

15 Circadian Rhythms and Shift Work 15 Stages 3/4 - Slow wave sleep (SWS), (delta sleep) Most restorative & restful; vital for physical recuperation. Most restorative & restful; vital for physical recuperation. Majority occurs early in the sleep period. Majority occurs early in the sleep period. Difficult to arouse from SWS. Difficult to arouse from SWS. First stage to be “made up” after sleep deprivation. First stage to be “made up” after sleep deprivation. SWS deprivation causes fatigue, muscle aches. SWS deprivation causes fatigue, muscle aches.

16 Circadian Rhythms and Shift Work 16 REM sleep brain on, body off. brain on, body off. Vital for psychological well-being; Vital for psychological well-being; Isolated REM deprivation -> 1 st irritability - > psychosis -> death Isolated REM deprivation -> 1 st irritability - > psychosis -> death EEG similar to wakefulness. EEG similar to wakefulness. Dreams, irregular pulse, respiration, increased BP, loss of muscle tone, and absent spinal reflexes. Dreams, irregular pulse, respiration, increased BP, loss of muscle tone, and absent spinal reflexes.

17 Circadian Rhythms and Shift Work 17 REM sleep First episode occurs after minutes of NREM sleep. First episode occurs after minutes of NREM sleep. Recurs in about 90 minute cycles, getting more frequent towards awakening Recurs in about 90 minute cycles, getting more frequent towards awakening REM periods become longer as night progresses. REM periods become longer as night progresses. REM disorders include sleepwalking / talking / night terrors REM disorders include sleepwalking / talking / night terrors

18 Circadian Rhythms and Shift Work 18 “Core Sleep” Horne: first three SWS cycles with their REM periods Horne: first three SWS cycles with their REM periods "optional" sleep the rest of the night: more REM, less SWS "optional" sleep the rest of the night: more REM, less SWS Core sleep: about 5 hours for most persons Core sleep: about 5 hours for most persons Only core sleep made up. Only core sleep made up.

19 Circadian Rhythms and Shift Work 19 “Sleepiness”“Sleepiness” 2 components: core versus optional 2 components: core versus optional missing core sleep (physiologic) -- disrupts physiologic systems missing core sleep (physiologic) -- disrupts physiologic systems missing optional sleep (psychological) -- mostly psychological / mood effects missing optional sleep (psychological) -- mostly psychological / mood effects

20 Circadian Rhythms and Shift Work 20 Excess Sleepiness in Shift Workers Up to 36% of rotating- shift workers experience ES. Up to 45% of night-shift workers experience ES.

21 Circadian Rhythms and Shift Work 21 Circadian disruption Day /awake and night / sleep are the normal human condition. Day /awake and night / sleep are the normal human condition. When switching to a day / sleep and night / awake, various physiologic cycles become desynchronized When switching to a day / sleep and night / awake, various physiologic cycles become desynchronized Hospitalization with loss of ‘Zeitgibers” Hospitalization with loss of ‘Zeitgibers” Re-synchronization at different rates Re-synchronization at different rates Generally, all systems can shift 1 hr per day. Generally, all systems can shift 1 hr per day.

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23 Circadian Rhythms and Shift Work 23 Adverse Health effects of shiftwork Breast Cancer, Endometrial Cancer : increased in women who are not exposed to enough darkness; mechanism unclear; proposed mechanism is melatonin deficiency. Breast Cancer, Endometrial Cancer : increased in women who are not exposed to enough darkness; mechanism unclear; proposed mechanism is melatonin deficiency. Prostate Cancer: increased most in rotating shift workers when compared to fixed-night shift- workers, who have an extremely minimal risk. Prostate Cancer: increased most in rotating shift workers when compared to fixed-night shift- workers, who have an extremely minimal risk. Peptic Ulcer Disease /Obesity / Cardiovascular Disease Peptic Ulcer Disease /Obesity / Cardiovascular Disease Pregnancy Issues: night work and high work load increase the risk of spontaneous abortion Pregnancy Issues: night work and high work load increase the risk of spontaneous abortion

24 Circadian Rhythms and Shift Work 24 Inter-relationships are complex Obesity, pregnancy, high fat diets and circadian rhythm Obesity, pregnancy, high fat diets and circadian rhythm Npas2 is a key organizer of the circadian system; if maternal diet is high fat, the fetal liver fetal histone code is mal- transcribed, and leads to appetite and circadian disorders in the offspring. Npas2 is a key organizer of the circadian system; if maternal diet is high fat, the fetal liver fetal histone code is mal- transcribed, and leads to appetite and circadian disorders in the offspring

25 Circadian Rhythms and Shift Work 25 Common Circadian Rhythm Disorders Jet Lag or Rapid Time Zone Change Syndrome: Jet Lag or Rapid Time Zone Change Syndrome: Delayed Sleep Phase Syndrome (DSPS) Delayed Sleep Phase Syndrome (DSPS) Advanced Sleep Phase Syndrome (ASPD) Advanced Sleep Phase Syndrome (ASPD) Shift Work Sleep Disorder (SWSD) Shift Work Sleep Disorder (SWSD)

26 Circadian Rhythms and Shift Work 26 Jet Lag / Shift work Personal cycles out of synchrony with local conditions. Personal cycles out of synchrony with local conditions. Sleepy when alertness is required; alert when sleep required Sleepy when alertness is required; alert when sleep required Caused by travel across time zones, shift work and sometimes by adolesnce Caused by travel across time zones, shift work and sometimes by adolesnce Can cause chronodysruption, since different systems re-synchronize at different rates. Can cause chronodysruption, since different systems re-synchronize at different rates.

27 Circadian Rhythms and Shift Work 27 Zeitgibers Zeitgibers (from Gr. “Time Tellers”) the physical and social clues which tell us what time it is. the physical and social clues which tell us what time it is. Most powerful is light. Most powerful is light. Others include taste and Others include taste and smell of usual breakfast smell of usual breakfast food, going to work, food, going to work, sound of daytime activities sound of daytime activities

28 Circadian Rhythms and Shift Work 28 Night Owls vs. Morning Larks Night people = easier adjustment to shift work Night people = easier adjustment to shift work Tend to be phase delayed Tend to be phase delayed Day people = harder with shift change; more stable once adjusted Day people = harder with shift change; more stable once adjusted Tend to be more synchronized and more resistant to re-setting Tend to be more synchronized and more resistant to re-setting Residency survey: EP s have more night types than normal populations Residency survey: EP s have more night types than normal populations

29 Circadian Rhythms and Shift Work 29 Delayed Sleep Phase Syndrome (DSPS) A disorder of sleep timing. A disorder of sleep timing. People with DSPS tend to fall asleep very late People with DSPS tend to fall asleep very late Difficulty waking up in time for work, school, or social engagements Difficulty waking up in time for work, school, or social engagements Common, perhaps normal in adolescence Common, perhaps normal in adolescence “Owls” “Owls”

30 Circadian Rhythms and Shift Work 30 Advanced sleep-phase syndrome (ASPS) ASPS persistent early evening sleep onset time (between 6:00 pm and 9:00 pm) and spontaneous early morning wake-up time (between 3:00 am and 5:00 am). ASPS persistent early evening sleep onset time (between 6:00 pm and 9:00 pm) and spontaneous early morning wake-up time (between 3:00 am and 5:00 am). Variably associated with inadquate sleep. Variably associated with inadquate sleep. Less common than DSPS Less common than DSPS Associated with extreme age and depression. Associated with extreme age and depression. “Larks” “Larks”

31 Circadian Rhythms and Shift Work 31 Non 24-Hour Sleep Wake Disorder (N24HS/W disorder): Innate hr cycles constantly reset by zeitgibers Innate hr cycles constantly reset by zeitgibers Normal sleep pattern but inate cylce is neither firm nor maintained. Normal sleep pattern but inate cylce is neither firm nor maintained. Struggles with “Free cycling” Struggles with “Free cycling” Inconsistent insomnia that occurs at different times each night. Inconsistent insomnia that occurs at different times each night.insomnia

32 Circadian Rhythms and Shift Work 32 Definitions for Emergency Medicine On - call On - call On duty On duty Sleep deprivation Sleep deprivation Chronodisruption Chronodisruption

33 Circadian Rhythms and Shift Work 33 On Call versus On Duty “On call”: night work between working days = pure sleep deprivation “On call”: night work between working days = pure sleep deprivation Possibility of sleep while on call Possibility of sleep while on call Usually does not cause circadian rhythm disruptions -- body cycles remain in phase Usually does not cause circadian rhythm disruptions -- body cycles remain in phase “On duty” implies expected time of usual type of work “On duty” implies expected time of usual type of work Isolated night shifts “on duty” (less than once per week) physiologically function as ‘on call’ Isolated night shifts “on duty” (less than once per week) physiologically function as ‘on call’

34 Circadian Rhythms and Shift Work 34 Sleep deprivation loss of "optional sleep" (sleeping less than one's habit) causes drowsiness, no other serious effects loss of "optional sleep" (sleeping less than one's habit) causes drowsiness, no other serious effects "core sleep" deprivation (less than 5 hours of slow wave sleep) "core sleep" deprivation (less than 5 hours of slow wave sleep) Sleep deprivation causes both physiologic and psychological ill effects Sleep deprivation causes both physiologic and psychological ill effects

35 Circadian Rhythms and Shift Work 35 Shift work prevalence Not a new phenomenon, but now vastly more frequent. Not a new phenomenon, but now vastly more frequent. 25% of American workers are shift workers at some point in their lives. 25% of American workers are shift workers at some point in their lives. Invention of the light bulb: 1883 Invention of the light bulb: 1883

36 Circadian Rhythms and Shift Work 36 Shift work definition Work a defined period of time, then off for a period Work a defined period of time, then off for a period Working time can be at any time of the 24-hr day Working time can be at any time of the 24-hr day Fixed shifts -- working the same time every day Fixed shifts -- working the same time every day Rotating shifts -- working time of day changes from time to time Rotating shifts -- working time of day changes from time to time

37 Circadian Rhythms and Shift Work 37 Shift length length of shift: most common is 8 hours length of shift: most common is 8 hours others are 10, 12 and 6 hours others are 10, 12 and 6 hours more mistakes made in the last 4 hours of a 12 hour shift than in the first 8 hours more mistakes made in the last 4 hours of a 12 hour shift than in the first 8 hours Shift changes become more difficult after age 40 Shift changes become more difficult after age 40

38 Circadian Rhythms and Shift Work 38 Serious adverse health consequences of shift work 20% decrease in life span 20% decrease in life span 62% sleep disturbance 62% sleep disturbance higher rate of accidents on the job higher rate of accidents on the job high risks of fatal commuting accidents high risks of fatal commuting accidents 800% risk of ulcers 800% risk of ulcers 1500% incidence of depression and mood swings 1500% incidence of depression and mood swings

39 Circadian Rhythms and Shift Work 39 Shift work is also linked to: drug and alcohol abuse drug and alcohol abuse altered immune response altered immune response infertility in women infertility in women high divorce rate. high divorce rate.

40 Circadian Rhythms and Shift Work 40 Cardiovascular effects of shift work is... linked to chronic hypertension linked to chronic hypertension increased cardiovascular mortality increased cardiovascular mortality (risk worse than smoking a pack of cigarettes per day) (risk worse than smoking a pack of cigarettes per day) risk for dysrhythmias (PVC, MAT, SVT) risk for dysrhythmias (PVC, MAT, SVT) risk of sinus arrest (up to 12 sec in one study) risk of sinus arrest (up to 12 sec in one study)

41 Circadian Rhythms and Shift Work 41 Tolerance to shift work Better in younger persons (under 40, or pre-menopausal) Better in younger persons (under 40, or pre-menopausal) Better in childless persons Better in childless persons Better in natural owls than natural larks Better in natural owls than natural larks 20% of people have no trouble changing shifts, 20% of people have no trouble changing shifts, 60% have moderate hardship, and 60% have moderate hardship, and 20% have extreme difficulty. 20% have extreme difficulty.

42 Circadian Rhythms and Shift Work 42 Shift work patterns most work has been done on 8 hour shifts most work has been done on 8 hour shifts 12 hour shifts no longer permitted in most industries 12 hour shifts no longer permitted in most industries rotating shifts rotating shifts isolated shifts isolated shifts random shifts random shifts

43 Circadian Rhythms and Shift Work 43 Shift schedules Optimum: days only; in synchronous with your own best working time Optimum: days only; in synchronous with your own best working time Next best: same shift every day, even if not most suited to your optimal time; or isolated nights Next best: same shift every day, even if not most suited to your optimal time; or isolated nights Worst: randomly rotating shifts Worst: randomly rotating shifts

44 Circadian Rhythms and Shift Work 44 Rotation patterns: Swing shifts Phase advance: one week days, one week evenings, one week nights Phase advance: one week days, one week evenings, one week nights Phase retreat: (Southern Swing): one week days, one week nights, one week evenings Phase retreat: (Southern Swing): one week days, one week nights, one week evenings Of the two, phase advance is more physiologic and more easily tolerated Of the two, phase advance is more physiologic and more easily tolerated

45 Circadian Rhythms and Shift Work 45

46 Circadian Rhythms and Shift Work 46 Randomly changing almost universally condemned almost universally condemned forbidden by most unions forbidden by most unions highest physiologic risk and stress highest physiologic risk and stress practiced mostly by physicians practiced mostly by physicians

47 Circadian Rhythms and Shift Work 47 Isolated nights defined as less than one night per week defined as less than one night per week equivalent to a bad night on call equivalent to a bad night on call

48 Circadian Rhythms and Shift Work 48

49 Circadian Rhythms and Shift Work 49 Important!Important! One can adjust by 1-2 hrs. / 24, or one week to move forward by one (8 hr) shift One can adjust by 1-2 hrs. / 24, or one week to move forward by one (8 hr) shift Therefore, maintain the same schedule when not working Therefore, maintain the same schedule when not working most permanent night workers switch to day-life when not at work and reap the same ill effects as random-shift changers most permanent night workers switch to day-life when not at work and reap the same ill effects as random-shift changers Optimal: one month or more between changes Optimal: one month or more between changes

50 Circadian Rhythms and Shift Work 50 What about physicians? MD = Maximum Denial MD = Maximum Denial Socialized to ignore their own needs Socialized to ignore their own needs Trained to be ‘tough’ Trained to be ‘tough’ poor role models poor role models

51 Circadian Rhythms and Shift Work 51 Cardiovascular effects in physicians: palpitations and dysrhythmias palpitations and dysrhythmias Brodsky M, Wu D, Denes P, Kanakis C, Rosen KM: Arrhythmias documented by 24 hour continuous electrocardiographic monitoring in 50 male medical students without apparent heart disease. Am J Cardiology 1977;39: Brodsky M, Wu D, Denes P, Kanakis C, Rosen KM: Arrhythmias documented by 24 hour continuous electrocardiographic monitoring in 50 male medical students without apparent heart disease. Am J Cardiology 1977;39:

52 Circadian Rhythms and Shift Work 52 Cardiovascular effects sinus arrest with syncope in residents sinus arrest with syncope in residents Guilleminault C, Pool P, Motta J, Gillis AM: Sinus arrest during REM sleep in young adults. NEJM: 1984;311: Guilleminault C, Pool P, Motta J, Gillis AM: Sinus arrest during REM sleep in young adults. NEJM: 1984;311:

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54 Circadian Rhythms and Shift Work 54 More studies Physicians aren’t immune to poor health effects of shift work Physicians aren’t immune to poor health effects of shift work Åkerstedt T, Knutsson A, Alfredsson L, Theorell T: Shift work and cardiovascular disease. J Work Environ Health: 1984; 10: Åkerstedt T, Knutsson A, Alfredsson L, Theorell T: Shift work and cardiovascular disease. J Work Environ Health: 1984; 10: Åkerstedt T. Psychological and psychophysiological effects of shift work. Scand J Work Environ Health. 1990;16(suppl 1):67-73 Åkerstedt T. Psychological and psychophysiological effects of shift work. Scand J Work Environ Health. 1990;16(suppl 1):67-73

55 Circadian Rhythms and Shift Work 55 Performance of physicians Poor performance with micro-sleeps (non- restorative) during rote tasks Poor performance with micro-sleeps (non- restorative) during rote tasks Documented micro and mini-sleeps during drive home even in those who did not think they had slept Documented micro and mini-sleeps during drive home even in those who did not think they had slept Åkerstedt et al: Physicians during and following night call duty--41 hour ambulatory recording of sleep. Electroencephalography & Clinical Neurophysiology: 1990; (76) Åkerstedt et al: Physicians during and following night call duty--41 hour ambulatory recording of sleep. Electroencephalography & Clinical Neurophysiology: 1990; (76)

56 Circadian Rhythms and Shift Work 56 Physician learning Decreased performance, learning of deleterious habits and physiologic harm. Decreased performance, learning of deleterious habits and physiologic harm. Asken MJ, Raham DC: Resident Performance and Sleep Deprivation: A Review. J. Med Educ 1983;58: Asken MJ, Raham DC: Resident Performance and Sleep Deprivation: A Review. J. Med Educ 1983;58:

57 Circadian Rhythms and Shift Work 57 Overall performance Found that shift work affected rote tasks and the highest intellectual tasks equally as much; moderately challenging but well known tasks suffered least. Implication for physicians: we make more mistakes on the more serious cases Found that shift work affected rote tasks and the highest intellectual tasks equally as much; moderately challenging but well known tasks suffered least. Implication for physicians: we make more mistakes on the more serious cases Tilley et al The sleep and performance of shift workers. Human Factors, 1982; 24: Tilley et al The sleep and performance of shift workers. Human Factors, 1982; 24:

58 Circadian Rhythms and Shift Work 58 Exercise tolerance Sleep deprivation had little effect on acute exercise tolerance in normal persons Sleep deprivation had little effect on acute exercise tolerance in normal persons Chen H: Effects of 30-h sleep loss on cardiorespiratory functions at rest and in exercise. Med Sci Sports and Exerc: 1991; 23(2): Chen H: Effects of 30-h sleep loss on cardiorespiratory functions at rest and in exercise. Med Sci Sports and Exerc: 1991; 23(2):

59 Circadian Rhythms and Shift Work 59 Shift length Used temperature as a marker for slowing of physiologic activities Used temperature as a marker for slowing of physiologic activities Concluded that 12 hour shifts lead to increased mistakes poorer per-hour productivity Concluded that 12 hour shifts lead to increased mistakes poorer per-hour productivity Daniel J, Potasova A; Oral temperature and performance in 8 h and 12 h shifts. Ergonomics 32(7):689-96, 1989 Jul. Daniel J, Potasova A; Oral temperature and performance in 8 h and 12 h shifts. Ergonomics 32(7):689-96, 1989 Jul.

60 Circadian Rhythms and Shift Work 60 Strategies to improve health for shift workers sleep hygiene sleep hygiene napping at work napping at work shift rotation patterns shift rotation patterns food & exercise food & exercise social life social life

61 Circadian Rhythms and Shift Work 61 If you must be a shift worker: Learn how to sleep well Learn how to sleep well Learn how to change your circadian rhythms smoothly Learn how to change your circadian rhythms smoothly Use circadian principles to make your work and home life better Use circadian principles to make your work and home life better Educate your schedule-maker Educate your schedule-maker Educate and enlist your family Educate and enlist your family

62 Circadian Rhythms and Shift Work 62 Living the Strategic Life Avoid vigorous exercise at least 4 hours prior to bedtime (Regular exercise is recommended.) Avoid vigorous exercise at least 4 hours prior to bedtime (Regular exercise is recommended.) Avoid cigarettes, alcohol, and caffeine 4-6 hours prior to bedtime Avoid cigarettes, alcohol, and caffeine 4-6 hours prior to bedtime Avoiding large meals and excessive fluids just before bedtime Avoiding large meals and excessive fluids just before bedtime

63 Circadian Rhythms and Shift Work 63 Light therapy: Timing of light Timing of light Minimum of minutes not long after wakening to promote adaptation and wakefullness Minimum of minutes not long after wakening to promote adaptation and wakefullness Re-synchronising ASPS light in the early evening and nighttime hours delays the cycle Re-synchronising ASPS light in the early evening and nighttime hours delays the cycle DSPS light therapy in the early morning hours stimulates morning alertness and an earlier bedtime. DSPS light therapy in the early morning hours stimulates morning alertness and an earlier bedtime.

64 Circadian Rhythms and Shift Work 64 Environmental control Light – adequate at work (6,000-7,000 Lux) Light – adequate at work (6,000-7,000 Lux) Dark – during sleep time (less than full moon) (consider eye shades) Dark – during sleep time (less than full moon) (consider eye shades) Noise – shut out during sleep. Isolate sleep room, use earplugs Noise – shut out during sleep. Isolate sleep room, use earplugs Room temperature – warm sleepers vs cool sleepers Room temperature – warm sleepers vs cool sleepers Exercise, Diet Exercise, Diet

65 Circadian Rhythms and Shift Work 65 Sleep Hygiene Temperature: between C Temperature: between C Bedroom: Condition yourself that Bed = Sleep time Bedroom: Condition yourself that Bed = Sleep time Ritual: helps to create a ‘stimulus- response’ conditioning Ritual: helps to create a ‘stimulus- response’ conditioning Keep sleep time sacred, and minimize care-giving responsibilities during that time. Keep sleep time sacred, and minimize care-giving responsibilities during that time.

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67 Circadian Rhythms and Shift Work 67 DietDiet troubled by early awakening? => try bedtime snack. troubled by early awakening? => try bedtime snack. Milk products seem to improve sleep. Milk products seem to improve sleep. Alcohol: a single drink can help tense people relax, but alcohol actually alters sleep structure by postponing REM Alcohol: a single drink can help tense people relax, but alcohol actually alters sleep structure by postponing REM Great care to eat appropriately during the working / waking time Great care to eat appropriately during the working / waking time

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69 Circadian Rhythms and Shift Work 69 ExerciseExercise Athletes: get more delta (SWS, restorative) sleep. Athletes: get more delta (SWS, restorative) sleep. Time of day important: pm exercise has more effect. Time of day important: pm exercise has more effect. Exercise should be completed more than one hour before sleep time Exercise should be completed more than one hour before sleep time

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71 Circadian Rhythms and Shift Work 71 Light – most important for humans intensity is important: 7,000 Lux intensity is important: 7,000 Lux about the same as a heavily overcast day about the same as a heavily overcast day most indoor lighting is inadequate most indoor lighting is inadequate new ‘energy saving’ fixtures are even more inadequate new ‘energy saving’ fixtures are even more inadequate implication to hospital administration: high intensity lights over physicians / nurses working areas improves productivity and minimizes mistakes. implication to hospital administration: high intensity lights over physicians / nurses working areas improves productivity and minimizes mistakes.

72 Circadian Rhythms and Shift Work 72

73 Circadian Rhythms and Shift Work 73 Timing of light pulses is important 2-3 hours of high intensity light within one hour of awakening 2-3 hours of high intensity light within one hour of awakening implication for shift workers: either go outside while the sun is still up before going to work the night shift, or buy and use a high intensity light at home implication for shift workers: either go outside while the sun is still up before going to work the night shift, or buy and use a high intensity light at home Fluorescents in windows. Fluorescents in windows.

74 Circadian Rhythms and Shift Work 74 Drugs and Pharmacology Drugs to sleep or to wake or re- synchronize Drugs to sleep or to wake or re- synchronize MDs: temptation and access to non-legal drug use MDs: temptation and access to non-legal drug use health care shift workers are at high risk for drug addiction health care shift workers are at high risk for drug addiction

75 Circadian Rhythms and Shift Work 75 Melatonin Melatonin is a re-synchronizer Melatonin is a re-synchronizer used in the treatment of circadian rhythm sleep disorder especially in blind persons used in the treatment of circadian rhythm sleep disorder especially in blind persons OTC “diet supplement” dosing guidelines not established. My use: OTC “diet supplement” dosing guidelines not established. My use:

76 Circadian Rhythms and Shift Work 76 MelatoninMelatonin 3-6 mg, taken one hour prior to desired (new) sleep time 3-6 mg, taken one hour prior to desired (new) sleep time Diminished (genetically?) in aging. Diminished (genetically?) in aging. Full effects of chronic exposure not yet known. Full effects of chronic exposure not yet known. Not FDA regulated, but seems to be extremely safe for brief use as in phase adjustment. Not FDA regulated, but seems to be extremely safe for brief use as in phase adjustment.

77 Circadian Rhythms and Shift Work 77 Melatonin stimulant Ramelteon (Rozerem) RamelteonRozeremRamelteonRozerem Rx only. Rx only. stimulates melatonin release stimulates melatonin release Ramelteon promotes the onset of sleep and helps normalize circadian rhythm disorders. Ramelteon promotes the onset of sleep and helps normalize circadian rhythm disorders. Ramelteon is approved by the Food and Drug Administration (FDA) for insomnia characterized by difficulty falling asleep. Ramelteon is approved by the Food and Drug Administration (FDA) for insomnia characterized by difficulty falling asleep.Food and Drug AdministrationFood and Drug Administration

78 Circadian Rhythms and Shift Work 78 Hypnotics: Benzodiazipines Benzodiazepines: short acting for sleep onset or napping. Triazolam (Halcion) Benzodiazepines: short acting for sleep onset or napping. Triazolam (Halcion)Triazolam Medium or long-acting: for sleep maintenance. estazolam [ProSom] quazepam [Doral] Medium or long-acting: for sleep maintenance. estazolam [ProSom] quazepam [Doral]estazolam quazepamestazolam quazepam Possibility of rebound insomnia Possibility of rebound insomnia

79 Circadian Rhythms and Shift Work 79 Benzodiazepines side effects can disrupt sleep architecture can disrupt sleep architecture may have residual sedative effects lasting into the next working period may have residual sedative effects lasting into the next working period many are fat soluble and will leach out over many days many are fat soluble and will leach out over many days illegal in some working environments illegal in some working environments

80 Circadian Rhythms and Shift Work 80 Non-benzodiazepine hypnotics Less effect on sleep architecture than benzos, less rebound insomnia Less effect on sleep architecture than benzos, less rebound insomniarebound Zolpidem (Ambien) moderate to long acting Zolpidem (Ambien) moderate to long acting Zolpidem Eszopicline (Lunesta) moderate duragion Eszopicline (Lunesta) moderate duragion Zaleplon (Sonata) short acting Zaleplon (Sonata) short acting

81 Circadian Rhythms and Shift Work 81 OTC hypnotics Benadryl – 25-50mg. Tachyphylaxis Benadryl – 25-50mg. Tachyphylaxis Alcohol – disrupts sleep architecture Alcohol – disrupts sleep architecture Herbs: hops, valerian, passion flower Herbs: hops, valerian, passion flower Marijuana – legal issues, prolonged effects Marijuana – legal issues, prolonged effects

82 Circadian Rhythms and Shift Work 82 Diphenhydramine / sedative antihistamines sedative antihistamines help induce sleep, and in some, help maintain sleep sedative antihistamines help induce sleep, and in some, help maintain sleep effect on sleep architecture is minimal effect on sleep architecture is minimal tachyphylaxis: effects wane within days tachyphylaxis: effects wane within days may produce prolonged sedation, interfering with performance and maintenance of new schedule when not at work may produce prolonged sedation, interfering with performance and maintenance of new schedule when not at work

83 Circadian Rhythms and Shift Work 83

84 Circadian Rhythms and Shift Work 84 AlcoholAlcohol disrupts sleep architecture disrupts sleep architecture delays REM sleep delays REM sleep variable effect on sleep latency variable effect on sleep latency recommendation for shift workers: finish your alcohol more than one hour before scheduled sleep time recommendation for shift workers: finish your alcohol more than one hour before scheduled sleep time

85 Circadian Rhythms and Shift Work 85 Cheat Sleep: stimulants OTC: primarily caffeine OTC: primarily caffeine Illegal: Cocaine, “Speed” and various “uppers” Illegal: Cocaine, “Speed” and various “uppers” Legal: Legal: amphetamines and amphetamine –like drugsamphetamines and amphetamine –like drugs Ampakines and their sucessorsAmpakines and their sucessors

86 Circadian Rhythms and Shift Work 86 Amphetamines methylphenidate (Ritalin, Metadate, Concerta) methylphenidate (Ritalin, Metadate, Concerta) methylphenidateRitalinMetadate, Concerta) methylphenidateRitalinMetadate, Concerta) dextroamphetamine Plus amphetamine (Adderall) dextroamphetamine Plus amphetamine (Adderall)Adderall Dextroamphetamine (Dexedrine) Dextroamphetamine (Dexedrine) DextroamphetamineDexedrine DextroamphetamineDexedrine lisdexamfetamine dimesylate – metabolized to methamphetamine (Vyvanse) lisdexamfetamine dimesylate – metabolized to methamphetamine (Vyvanse) lisdexamfetamine dimesylate lisdexamfetamine dimesylate

87 Circadian Rhythms and Shift Work 87 Ampakines and their successors Modafinil (Provigil, Alertec, Modavigil, Modalert, Modiodal, Modafinilo, Carim, Vigia) Modafinil (Provigil, Alertec, Modavigil, Modalert, Modiodal, Modafinilo, Carim, Vigia) analeptic drug manufactured by Cephalon, and is approved by the FDA for shift workers analeptic drug manufactured by Cephalon, and is approved by the FDA for shift workers Armodafinil (Nuvigil) is the active (−)-(R)- enantiomer of the racemic drug modafinil Armodafinil (Nuvigil) is the active (−)-(R)- enantiomer of the racemic drug modafinil enantiomerracemicmodafinil enantiomerracemicmodafinil Side effects include potentially cognitive enhancement, and loss of effect of BCPs Side effects include potentially cognitive enhancement, and loss of effect of BCPs

88 Circadian Rhythms and Shift Work 88 CaffeineCaffeine harmless in small doses harmless in small doses taking caffeine to get through the night shift may interfere with day sleep taking caffeine to get through the night shift may interfere with day sleep careful with timing of caffeine intake careful with timing of caffeine intake

89 Circadian Rhythms and Shift Work 89 Optimal phase adjustment strategies bright light early in waking time bright light early in waking time significant exercise later in waking period significant exercise later in waking period optimize sleeping conditions: aluminum- foil on the windows, ear plugs, eye shades, fan optimize sleeping conditions: aluminum- foil on the windows, ear plugs, eye shades, fan stay on the same schedule without varying by more than an hour as long as you can stay on the same schedule without varying by more than an hour as long as you can Consider Melatonin. Consider Melatonin.

90 Circadian Rhythms and Shift Work 90 SummarySummary American society is more 24 / 7 American society is more 24 / 7 EM always 24 / 7 EM always 24 / 7 Use circadian principles to improve your well being and prolong your professional life and your personal life Use circadian principles to improve your well being and prolong your professional life and your personal life

91 Circadian Rhythms and Shift Work 91 Resources American Academy of Sleep Medicine One Westbrook Corporate Center, Suite 920 Westchester, IL (708) American Academy of Sleep Medicine One Westbrook Corporate Center, Suite 920 Westchester, IL (708) American Academy of Sleep Medicine American Academy of Sleep Medicine National Sleep Foundation 1522 K Street, NW, Suite 500 Washington, DC National Sleep Foundation 1522 K Street, NW, Suite 500 Washington, DC National Sleep Foundation National Sleep Foundation

92 Circadian Rhythms and Shift Work 92 Enhancing adaption Rotating shiftwork schedules: can we enhance physician adaptation to night shifts? Smith-Coggins R, Rosekind MR, Buccino KR, Dinges DF, Moser RP Acad Emerg Med 1997 Oct;4(10): Rotating shiftwork schedules: can we enhance physician adaptation to night shifts? Smith-Coggins R, Rosekind MR, Buccino KR, Dinges DF, Moser RP Acad Emerg Med 1997 Oct;4(10):951-61

93 Circadian Rhythms and Shift Work 93 Best single reference "Why we Sleep" by James Horne. Published by Oxford University Press Walton St Oxford OX2 6DP 1988 "Why we Sleep" by James Horne. Published by Oxford University Press Walton St Oxford OX2 6DP 1988 a classic overall reference a classic overall reference

94 Circadian Rhythms and Shift Work 94 Web Links Northwestern University, Center for Sleep & Circadian Biology, Northwestern University, Center for Sleep & Circadian Biology, About Circadian Rhythms National Sleep Foundation, About Circadian Rhythms National Sleep Foundation, About Circadian Rhythms About Circadian Rhythms Strategies for Shift Workers Strategies for Shift Workers Strategies for Shift Workers Strategies for Shift Workers National Sleep Foundation, National Sleep Foundation, Sleep and the Traveler Sleep and the Traveler Sleep and the Traveler Sleep and the Traveler National Institute of Mental Health, How Biological Clocks Work National Institute of Mental Health, How Biological Clocks Work National Institute of Mental HealthHow Biological Clocks Work National Institute of Mental HealthHow Biological Clocks Work Sleepnet.com Sleepnet.com Sleepnet.com


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