sleep, circadian rhythms, and medical training daniel j. buysse, m.d. professor of psychiatry e-1127...

Sleep, circadian rhythms, and medical Sleep, circadian rhythms, and medical trainingtraining

Daniel J. Buysse, M.D.Daniel J. Buysse, M.D.

Professor of PsychiatryProfessor of Psychiatry

E-1127 WPICE-1127 WPIC

(412) 246-6413(412) 246-6413

[email protected]@upmc.edu

Sleep, circadian rhythms, and medical Sleep, circadian rhythms, and medical training: Objectivestraining: Objectives

To briefly review circadian rhythms in humansTo briefly review circadian rhythms in humans To briefly review sleep and sleep deprivation To briefly review sleep and sleep deprivation

effects in humanseffects in humans To discuss the impact of sleep and fatigue on To discuss the impact of sleep and fatigue on

medical traineesmedical trainees To review management strategies for sleep To review management strategies for sleep

lossloss

What are circadian rhythms?What are circadian rhythms?

Approximately 24-hour rhythms in Approximately 24-hour rhythms in physiological, psychological, performance physiological, psychological, performance measures… including sleep and wakefulnessmeasures… including sleep and wakefulness

Endogenous: Property of the organism, not Endogenous: Property of the organism, not the environmentthe environment– Pacemaker is suprachiasmatic nucleus (SCN) Pacemaker is suprachiasmatic nucleus (SCN)

of the hypothalamusof the hypothalamus

– Regulation by rhythmic expression of gene Regulation by rhythmic expression of gene transcription productstranscription products

Influenced by Influenced by entrainmententrainment and and masking masking effectseffects of the environment of the environment

How are doctors and their patients How are doctors and their patients alike?alike?

They both have circadian rhythmsThey both have circadian rhythms They both need sleepThey both need sleep The both suffer from the effect of sleep lossThe both suffer from the effect of sleep loss

Examples of Examples of humanhumancircadian circadian rhythmsrhythmsCzeisler and Khalsa, 2000Czeisler and Khalsa, 2000

Core body temperature

Urine volume

Thyroid StimulatingHormone

Growth Hormone

Prolactin

Parathyroid Hormone

Motor activity

Cortisol

Time

Circadian rhythms in performanceDijk and Edgar, 1999

Single-occupant motor vehicle crashesSingle-occupant motor vehicle crashesPack et al., SLEEP, 1995Pack et al., SLEEP, 1995

Circadian Rhythms

Suprachiasmatic Nuclei (SCN)

Light

Output Rhythms

Physiology Behavior

Entrainment by light in a human subject Moore-Ede, 1982

Time of Day (hours)

Scheduled rest-activity

Unscheduled “free-running”

Scheduled light-dark schedule

Unscheduled “free-running”

Scheduled light-dark schedule





lossloss

Sleep and wakefulnessSleep and wakefulness

Three fundamental behavioral/neurological Three fundamental behavioral/neurological states of healthy mammalsstates of healthy mammals– WakefulnessWakefulness

– Non-rapid eye movement (NREM) sleepNon-rapid eye movement (NREM) sleep

– Rapid eye movement (REM) sleepRapid eye movement (REM) sleep Endogenous neural controlEndogenous neural control

– Widely distributed sleep/wake centersWidely distributed sleep/wake centers

– Linked to circadian systemLinked to circadian system Influenced by numerous exogenous factors… Influenced by numerous exogenous factors…

including voluntary behavior including voluntary behavior

Sleep in healthy young womanSleep in healthy young woman

Homeostatic and circadian regulation of human sleep Borbely et al., 2001

Time of Day

Sleep propensity

Sleep propensity

High

High

Low

Low

What is sleep good for?What is sleep good for?

Cognitive functionCognitive function LearningLearning Mood regulationMood regulation Metabolic functionMetabolic function

Sleep and learning in a visual taskSleep and learning in a visual taskStickgold, Stickgold, ScienceScience, 2001, 2001

Retesting after wakefulnessor sleep

Retesting over one week

Sleep after learning

Sleep deprivation after learning





lossloss

© American Academy of Sleep Medicine

American Academy of Sleep Medicine

Mustafa and Strohl, unpublished data. Papp, 2002

Sleepiness in Residents: Epworth Sleepiness in Residents: Epworth Sleepiness ScaleSleepiness Scale


0

5

10

15

20

Mean 5.90 2.20 11.70 14.70 17.50

Normal Insomnia Sleep Apnea Residents Narcolepsy



Sleepiness in Residency is Under-Sleepiness in Residency is Under-recognized: Why?recognized: Why?

Physicians know relatively little about sleepPhysicians know relatively little about sleep needs and sleep physiology. needs and sleep physiology.

There is no “drug test” for sleepiness.There is no “drug test” for sleepiness.

Most programs do not recognize and address Most programs do not recognize and address the problem of resident sleepiness. the problem of resident sleepiness.

The culture of medicine says:The culture of medicine says:

– “ “Sleep is “optional” (and you’re a wimp if Sleep is “optional” (and you’re a wimp if you need it)” you need it)”

– “ “Less sleep = more dedicated doc”Less sleep = more dedicated doc”




Conceptual Framework (in Conceptual Framework (in Residency)Residency)

PrimarySleep Disorders(sleep apnea, etc)

Fragmented Sleep(pager, phone calls)

Circadian Rhythm Disruption(night float, rotating shifts)

Insufficient Sleep(on call sleep loss/inadequate

recovery sleep)

EXCESSIVE DAYTIME SLEEPINESS




Sleep Needed vs. Sleep ObtainedSleep Needed vs. Sleep Obtained

Myth:Myth: “ “I’m one of those people who only need 5 I’m one of those people who only need 5 hours of sleep, so none of this applies to hours of sleep, so none of this applies to me.”me.” Fact:Fact: Individuals may vary somewhat in their Individuals may vary somewhat in their

tolerance to the effects of sleep loss, but are not tolerance to the effects of sleep loss, but are not able to accurately judge this themselves. able to accurately judge this themselves.

Fact:Fact: Human beings need approximately 8 hours of Human beings need approximately 8 hours of sleep to perform at an optimal level. sleep to perform at an optimal level.

Fact:Fact: Getting less than 8 hours of sleep starts to Getting less than 8 hours of sleep starts to create a “sleep debt” which must be paid off. create a “sleep debt” which must be paid off.




Sleep Fragmentation Affects Sleep Sleep Fragmentation Affects Sleep QualityQuality

= Paged

NORMAL SLEEP

ON CALL SLEEP

MORNING ROUNDS


Homeostatic and circadian regulation Homeostatic and circadian regulation of human sleep of human sleep Borbely et al., 2001Borbely et al., 2001

Time of Day

American Academy of Sleep MedicineAmerican Academy of Sleep Medicine

Time of Day

Sleep propensity

Sleep propensity

High

High

Low

Low



Sleep Disorders: Are you at risk?Sleep Disorders: Are you at risk?

Physicians can have sleep disorders too!Physicians can have sleep disorders too!– Obstructive sleep apnea: Snoring, obesity, Obstructive sleep apnea: Snoring, obesity,

sleepinesssleepiness– Restless legs syndrome: Urge to move legs Restless legs syndrome: Urge to move legs

associated with dysesthesiasassociated with dysesthesias– Periodic limb movement disorder: Repeated leg Periodic limb movement disorder: Repeated leg

jerks with arousals jerks with arousals – Learned or “conditioned” insomnia: Unable to Learned or “conditioned” insomnia: Unable to

sleep despite adequate opportunitysleep despite adequate opportunity– Medication-induced insomniaMedication-induced insomnia




Adaptation to Sleep LossAdaptation to Sleep Loss

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: Although performance of tasks may improve somewhat with effort, optimal performance and consistency of performance do not!


Sleepiness and sleep deprivationSleepiness and sleep deprivationBelenky, Belenky, J. Sleep ResearchJ. Sleep Research, 2003, 2003

Performance and sleep deprivationPerformance and sleep deprivationBelenky, Belenky, J. Sleep ResearchJ. Sleep Research, 2003, 2003


Learning

DrivingSafety

Health&

Well-BeingFamily

Relationships

Patient CareProfessionalism

MoodAnd

Performance

Workplace

Sleep DeprivedSleep DeprivedResidentResident

Learning

DrivingSafety

Health&

Well-BeingFamily

Relationships

Patient CareProfessionalism

MoodAnd

Performance

Workplace

Sleep DeprivedSleep DeprivedResidentResident


Consequences of Chronic Sleep Consequences of Chronic Sleep DeprivationDeprivation




Surgery:Surgery: 20% more errors and 20% more errors and 14% more time required to 14% more time required to perform simulated laparoscopy perform simulated laparoscopy post-call (two studies) post-call (two studies) Taffinder et al, Taffinder et al, 1998; Grantcharov et al, 20011998; Grantcharov et al, 2001

Internal Medicine:Internal Medicine: efficiency and efficiency and accuracy of ECG interpretation accuracy of ECG interpretation impaired in sleep-deprived interns impaired in sleep-deprived interns Lingenfelser et al, 1994Lingenfelser et al, 1994

Pediatrics:Pediatrics: time required to place time required to place an intra-arterial line increased an intra-arterial line increased significantly in sleep-deprived significantly in sleep-deprived Storer et al, 1989Storer et al, 1989

Across SpecialtiesAcross Specialties


Effects of sleep deprivation on mood in Effects of sleep deprivation on mood in medical residentsmedical residents Baldwin and Daugherty, Baldwin and Daugherty, SleepSleep, , 20042004

2

3

4

5

6

7

<4 4 to 5 5 to 6 6 to 7 >7

Average Hours of Sleep per Night

Res

iden

ts' R

atin

gs

Moodier & more shorttempered

Impaired my capacityto care for patients

Work hours too long

More conflict withprofessional staff

Misjudgements inpatient care



Impact on Medical ErrorsImpact on Medical Errors

Surveys:Surveys: more than 60 % of anesthesiologists more than 60 % of anesthesiologists report making fatigue-related errors. report making fatigue-related errors. Gravenstein 1990Gravenstein 1990

Case Reviews:Case Reviews:– 3% of anesthesia incidents 3% of anesthesia incidents Morris 2000Morris 2000

– 5% “preventable incidents”5% “preventable incidents”– 10% drug errors 10% drug errors Williamson 1993 Williamson 1993

– Post-op surgical complication rates 45%, higher if Post-op surgical complication rates 45%, higher if resident was post-call resident was post-call Haynes et al 1995Haynes et al 1995


“Fatigue related”

Risk of motor vehicle accidents after Risk of motor vehicle accidents after extended and nonextended shiftsextended and nonextended shiftsBarger, Barger, NEJMNEJM 2005; 52:125-34 2005; 52:125-34

Work shiftWork shift

≥≥24 hours24 hoursWork shiftWork shift

<24 hours<24 hours

Odds RatioOdds Ratio

CrashesCrashes 5858 7373 2.3 (1.6-3.3)2.3 (1.6-3.3)

Near-missesNear-misses 1,9711,971 1,1561,156 5.9 (5.4-6.3)5.9 (5.4-6.3)

CommutesCommutes 54,12154,121 180,289180,289

Risk of motor vehicle accidents after Risk of motor vehicle accidents after extended and nonextended shiftsextended and nonextended shiftsBarger, Barger, NEJMNEJM 2005; 52:125-34 2005; 52:125-34

Number of extended shifts per month

0 1 - 4 ≥5

Rat

e of

pos

itiv

e re

spon

se

Nod off driving OR=2.39 (2.31-2.46)Nod off in traffic OR 3.69 (3.60-3.77)





lossloss



Estimating SleepinessEstimating Sleepiness

Myth:Myth: “I can tell how tired I am and I know when “I can tell how tired I am and I know when I’m not functioning up to par.”I’m not functioning up to par.” Fact:Fact: Studies show that sleepy people Studies show that sleepy people underestimate underestimate their level of sleepiness their level of sleepiness and and overestimateoverestimate their alertness. their alertness. Fact:Fact: The sleepier you are, the The sleepier you are, the less accurateless accurate

your perception of degree of impairment. your perception of degree of impairment. Fact:Fact: You can fall asleep briefly (“microsleeps”) You can fall asleep briefly (“microsleeps”)

without knowing it! without knowing it!




Anesthesia resident studyAnesthesia resident study

Residents did not perceive themselves to be asleep Residents did not perceive themselves to be asleep almost half of the time they had actually fallen asleep.almost half of the time they had actually fallen asleep.

Residents were wrong 76% of the time when they Residents were wrong 76% of the time when they reported having stayed awake. reported having stayed awake. Howard et al 2002Howard et al 2002




Recognize the warning signs of sleepinessRecognize the warning signs of sleepiness

Falling asleep in conferences or on roundsFalling asleep in conferences or on rounds Feeling restless and irritable with staff, Feeling restless and irritable with staff,

colleagues, family, and friends colleagues, family, and friends Having to check your work repeatedly Having to check your work repeatedly Having difficulty focusing on the care of your Having difficulty focusing on the care of your

patientspatients Feeling like you really just don’t careFeeling like you really just don’t care




Myth:Myth: “I’d rather just “power “I’d rather just “power through” when I’m tired; through” when I’m tired; besides, even when I can besides, even when I can nap, it just makes me feel nap, it just makes me feel worse.” worse.”

Fact:Fact: Some sleep is always better Some sleep is always better than no sleep. than no sleep.

Fact:Fact: At At what timewhat time and for and for how how long long you sleep are key to you sleep are key to getting the most out of getting the most out of napping. napping.

Alertness Management StrategiesAlertness Management Strategies




NappingNapping

Rationale:Rationale: Naps temporarily improve alertnessNaps temporarily improve alertness TypesTypes

– Preventative (pre-call)Preventative (pre-call)– Operational (on the job)Operational (on the job)

LengthLength– Short napsShort naps: No longer than 30 minutes to avoid : No longer than 30 minutes to avoid

the grogginess (“sleep inertia”) that occurs with the grogginess (“sleep inertia”) that occurs with awakening from deep sleepawakening from deep sleep

– Long napsLong naps: 2 hours (range 30 to 180 minutes): 2 hours (range 30 to 180 minutes)




NappingNapping

TimingTiming– If possible, take advantage of circadian “windows If possible, take advantage of circadian “windows

of opportunity” (2-5 am and 2-5 pm) of opportunity” (2-5 am and 2-5 pm) – But if not, nap whenever you can!But if not, nap whenever you can!

ConsCons– Sleep inertiaSleep inertia– Allow adequate recovery time (15-30 minutes)Allow adequate recovery time (15-30 minutes)

Bottom line:Bottom line: Naps take the edge off but Naps take the edge off but do not do not replacereplace adequate night sleep adequate night sleep




Get adequate (7 to 9 hours) sleep Get adequate (7 to 9 hours) sleep beforebefore anticipated sleep lossanticipated sleep loss

Avoid Avoid starting outstarting out with a sleep deficit with a sleep deficit

Healthy sleep habitsHealthy sleep habits




Recovery from Sleep LossRecovery from Sleep Loss

Myth:Myth: “All I need is my usual 5 to 6 hours the“All I need is my usual 5 to 6 hours the night after call and I’m fine.” night after call and I’m fine.”

Fact:Fact: Recovery from on-call sleep loss Recovery from on-call sleep loss generally takes 2 nights of extended generally takes 2 nights of extended sleep to restore baseline alertness. sleep to restore baseline alertness.

Fact:Fact: Recovery sleep generally has a higher Recovery sleep generally has a higher percentage of deep sleep, which is percentage of deep sleep, which is needed to counteract the effects of sleep needed to counteract the effects of sleep loss. loss.


Objective sleepiness: Baseline, post-call, Objective sleepiness: Baseline, post-call, and extended recovery and extended recovery Howard, 2002Howard, 2002



Time to fall asleep

on MSLT (min)


0

5

10

15

20

1000 1200 1400 1600 1800

Time of Day

Post-call Baseline Extended



Healthy sleep habitsHealthy sleep habits

Go to bed and get up at about the same time

every day Develop a pre-sleep routine to wind down Create a comfortable environment for sleep Get regular exercise if possible Protect your sleep time

Enlist your family and friendsMinimize interruptions


Effect of traditional and limited work Effect of traditional and limited work schedules on sleep and attention in schedules on sleep and attention in internsinterns Lockley, Lockley, NEJMNEJM 2004; 351:1829-37 2004; 351:1829-37Work hours/ week Sleep hours/ week

p<.001 p<.001

Hou

rs

Traditional schedule

Attentional failures/ hour 11pm - 7am

p=.02

Failu

res

/ ho

ur

Limited hours schedule

Effect of traditional and limited work Effect of traditional and limited work schedules on medical errors in internsschedules on medical errors in internsLandrigan, Landrigan, NEJMNEJM 2004; 351:1838-48 2004; 351:1838-48

Serious Medication medical errors errors p<.001 p<.03

Num

ber

Traditional schedule

Procedural Diagnostic errors errors p=.34 p<.001

Num

ber

Limited hours schedule



Recognize signs of drowsiness while Recognize signs of drowsiness while drivingdriving Trouble focusing on the road Difficulty keeping your eyes open Nodding Yawning repeatedly Drifting from your lane, missing signs or exits Not remembering driving the last few miles Closing your eyes at stoplights




Drive smart; Drive safeDrive smart; Drive safe

It takes only a 4 second lapse in attention to have a It takes only a 4 second lapse in attention to have a drowsy driving crashdrowsy driving crash

AVOID driving if drowsy AVOID driving if drowsy If you are really sleepy, get a ride home, take a taxi, If you are really sleepy, get a ride home, take a taxi,

or use public transportationor use public transportation Take a 20 minute nap and/or drink a cup of coffee Take a 20 minute nap and/or drink a cup of coffee

before going home post-callbefore going home post-call Stop driving if you notice the warning signs of Stop driving if you notice the warning signs of

sleepinesssleepiness Pull off the road at a safe place, take a short napPull off the road at a safe place, take a short nap




Drowsy driving: What does not workDrowsy driving: What does not work

Turning up the radioTurning up the radio Opening the car windowOpening the car window Chewing gumChewing gum Blowing cold air (water) on your faceBlowing cold air (water) on your face Slapping (pinching) yourself hardSlapping (pinching) yourself hard Promising yourself a reward for staying awakePromising yourself a reward for staying awake




DrugsDrugs Melatonin:Melatonin: Few data in residents Few data in residents Hypnotics:Hypnotics: May be helpful in May be helpful in specificspecific situations situations

– Persistent insomniaPersistent insomnia

– Scheduled night shift/ day sleep with no daytime Scheduled night shift/ day sleep with no daytime responsibilityresponsibility

– Short-acting agents (zolpidem, triazolam, zaleplon, Short-acting agents (zolpidem, triazolam, zaleplon, eszopiclone) generally preferredeszopiclone) generally preferred

– Ensure adequate time for sleepEnsure adequate time for sleep AVOIDAVOID alcohol to help you fall asleep alcohol to help you fall asleep

– Alcohol induces sleep onset…Alcohol induces sleep onset…

– ……but disrupts sleep later onbut disrupts sleep later on AVOIDAVOID regular use of stimulants (methylphenidate, regular use of stimulants (methylphenidate,

dextroamphetamine, modafinil) to stay awakedextroamphetamine, modafinil) to stay awake




CaffeineCaffeine

StrategicStrategic consumption is key consumption is key Effects within 15 – 30 minutes; half-life 3 to 7 hoursEffects within 15 – 30 minutes; half-life 3 to 7 hours Use for temporary relief of sleepinessUse for temporary relief of sleepiness Cons: Cons:

– disrupts subsequent sleep (more arousals)disrupts subsequent sleep (more arousals)– tolerance may develop tolerance may develop

– diuretic effectsdiuretic effects




Adapting to night shiftAdapting to night shift

Myth:Myth: “I get used to night shifts right away; no“I get used to night shifts right away; no problem.” problem.”

Fact:Fact: It takes about one day to adjust to each one It takes about one day to adjust to each one hour of time zone change. hour of time zone change.

Fact:Fact: Adjustment often includes physical and Adjustment often includes physical and mental symptoms (think mental symptoms (think jet lag). jet lag).

Fact:Fact: Studies of chronic, well-adapted, full-time Studies of chronic, well-adapted, full-time night shift workers show night shift workers show no adaptationno adaptation of of physiological phase markers.physiological phase markers.




How to survive night floatHow to survive night float

Protect your sleepProtect your sleep Ensure optimal sleep environmentEnsure optimal sleep environment Nap before workNap before work Consider “splitting” sleep into two 4 hour periods.Consider “splitting” sleep into two 4 hour periods. Have as much exposure to bright light as possible Have as much exposure to bright light as possible

when you need to be alertwhen you need to be alert Avoid light exposure in the morning after night shift Avoid light exposure in the morning after night shift

(dark glasses driving home from work?)(dark glasses driving home from work?)




Alertness strategiesAlertness strategies

There is no “magic bullet” There is no “magic bullet” Know your own vulnerability to sleep lossKnow your own vulnerability to sleep loss Learn what works for you from a range of Learn what works for you from a range of

strategiesstrategies There needs to be a shared responsibility There needs to be a shared responsibility

for fatigue management and a “culture for fatigue management and a “culture of support” in the training programof support” in the training program




In summary…In summary…

Fatigue/sleepiness is an impairment like alcohol or Fatigue/sleepiness is an impairment like alcohol or drugs.drugs.

Drowsiness, sleepiness, and fatigue cannot be Drowsiness, sleepiness, and fatigue cannot be eliminated in residency, but can be managed.eliminated in residency, but can be managed.

Help combat sleepiness in residencyHelp combat sleepiness in residency– Recognition of sleepinessRecognition of sleepiness– Use of alertness management strategiesUse of alertness management strategies

When sleepiness interferes with your performance When sleepiness interferes with your performance or health, talk to your supervisors and program or health, talk to your supervisors and program directordirector




““Patients have a right to expect a healthy, alert, Patients have a right to expect a healthy, alert, responsible, and responsive physician.”responsible, and responsive physician.”

January 1994 statement by American College of Surgeons January 1994 statement by American College of Surgeons

Re-approved and re-issued June 2002Re-approved and re-issued June 2002


sleep, circadian rhythms, and medical training daniel j. buysse, m.d. professor of psychiatry e-1127...

Documents

impact of sleep

sleep retesting

week sleep

sleep deprivation effects

effect of sleep loss

environment slide

circadian system

hour rhythms