Fatigue is an occupational risk of medical training. It affects patient safety, physician wellbeing, and resident learning. It can’t be eliminated, but it can be anticipated, recognized, and managed. This page summarizes practical, evidence-based strategies for residents, adapted from my teaching presentation on fatigue risk management (FRM).
What is fatigue?
Fatigue is a physical, mental or cognitive state of tiredness. It reduces your ability (or your perceived ability) to complete a task safely and effectively. One of its hallmarks is more variable performance as time on task increases. Fatigue may be:
Acute or episodic: for example, after a single overnight call.
Chronic or cumulative: from repeated sleep restriction over weeks (heavy rotation ex. ICU)
Recognizing fatigue
Physical signs: heavy eyelids or eyelid twitching, yawning, muscle tension (jaw, shoulders, hands), headache or migraine, poor coordination, and appetite changes. Over the longer term, watch for recurrent illness or injury.
Cognitive and functional signs: slower reaction time, attention lapses, distractibility, and difficulty with working memory, problem solving and decision making.
Emotional signs: irritability, apathy, giddiness, reduced empathy, strained relationships with the team, and poorer emotional regulation.
Why it matters: fatigue in healthcare workers is linked to motor vehicle collisions, needlestick injuries, perseverative errors, and more risk-taking behaviours.
The “fatigue paradox”: physicians readily accept that fatigue impairs performance in general. They’re much less willing to accept that it affects their own patient care. Contributing factors include the “indefatigable physician” ideal, faith in safety nets, a lack of feedback, and minimizing fatigue-related events. For more information, The Fatigue Paradox paper from E. Field and T. Taylor is a great read.
Duty hours: not the whole story
In Canada, resident duty hours are set province by province, mostly through housestaff collective agreements. In Quebec, a 2011 labour arbitration ruling found that 24-hour in-house call violated the Canadian and Quebec Charters of Rights and Freedoms, and shifts are now capped at 16 hours.
The evidence on shorter shifts is mixed. Large studies have not shown clear benefits on patient mortality. Rapidly cycling schedules with shorter shifts can increase sleep, but they also bring more short turnarounds between shifts and, for some residents, a worse educational experience. (See ROSTERS papers in Sleep and in NEJM).
Bottom line: fatigue is often unavoidable in training. Hours worked are only part of the picture. How you sleep, when you sleep, and how you manage fatigue matter just as much.
Three steps to managing fatigue
1. Know your sleep requirement
Most adults need 7 to 9 hours of sleep. Very few people function well on less than 6.
To estimate your own need, look at how much you sleep on vacation or on weekends without an alarm.
Sleep debt adds up. If you need 8.5 hours and get 6.25 on weeknights, that’s more than 4 hours of “debt” each week. Sleep debt and sleep recovery does not act as a 1-to-1 recovery.
Recovery takes time. Recovering from a night of acute sleep loss takes at least 2-3 nights. Weekend sleep-ins don’t repay chronic debt accumulated over a week.
Deep sleep (N3) is concentrated early in the night and is recovered first.
REM sleep is concentrated in the early morning and is the first to be cut short when you wake early.
Sleep recovery combines homeostasis and circadian factors, which is why more than 1 night of recovery is required.
Regular timing stabilizes sleep. An irregular schedule, sleep debt, and untreated sleep disorders can all fragment sleep.
Aim for enough sleep on at least 5 of 7 nights, with a consistent “anchor” schedule on working days and days off.
2. Understand your chronotype
Your circadian rhythm controls alertness, body temperature, appetite, and more, and it isn’t the same as your sleep-wake schedule. Most internal clocks run slightly longer than 24 hours.
Night owls tend to drift later. Their performance usually bottoms out around 03:00.
Morning larks run earlier. Their dip comes sooner, around 01:00.
Light is the strongest signal for setting your clock. At the right time, it improves mood and alertness. At the wrong time, it shifts or disrupts your rhythm.
How to optimize circadian rhythm day-to-day:
Schedule cognitively demanding work for your peak hours, and routine tasks for your low periods.
Night owls: get bright morning light (outdoors or a 10,000-lux light box), avoid bright evening light, avoid long weekend sleep-ins, and protect early mornings from heavy cognitive work.
Morning larks: protect your mornings for complex work, and use evening light when you need to stay alert.
How to optimize circadian rhythm on call:
Plan breaks or fatigue countermeasures around your expected circadian low.
Avoid low-acuity but cognitively heavy tasks (discharge summaries, complex orders) for the circadian low point.
Coordinate with nurses, co-residents, and staff so that someone alert is aware and/or covering when you’re at your lowest.
3. Build a fatigue toolkit
Self-assessment before and during a shift. The Samn-Perelli scale comes from aviation and has been adapted for healthcare:
Fully alert, wide awake
Very lively, responsive, but not at peak
Okay, somewhat fresh
A little tired, less than fresh
Moderately tired, let down
Extremely tired, very difficult to concentrate
Completely exhausted, unable to function effectively
At 5 or above, use countermeasures and tell your team. At a 7, you’re not safe for complex tasks or for driving. Reassign tasks and ask for help if possible.
Other tools include the Karolinska and Epworth sleepiness scales.
Before call:
Extend your sleep the night before, and sleep without an alarm if you can.
Take a prophylactic nap of 20 to 40 minutes before or early in the shift. In aviation research, naps taken early in the operation were the most effective at limiting fatigue.
During call:
Naps: 10 minutes or more helps. Keep naps under about 40 minutes to avoid sleep inertia, or take a full sleep cycle if you get protected time.
“Nappuccino”: drink about 100 mg of caffeine (roughly 250 mL of brewed coffee), then nap for 20 to 25 minutes right away. The caffeine takes effect as you wake, which offsets sleep inertia.
Caffeine: avoid it in the last 4 hours of your shift. It will impair your recovery sleep.
Bright light, short bursts of activity, conversation, cold water on the face, and nutritious snacks rather than heavy meals.
Task strategies: slow down, rotate and buffer tasks, delegate, and double-check high-risk orders and calculations.
Behaviour strategies: verbalize your reasoning, use closed-loop communication, and ask for closer supervision when you’re impaired.
Getting home safely:
The drive home after call is a high-risk period.
If you’re drowsy, use a taxi, rideshare, transit or a ride from someone, or nap before you drive.
Opening the window and turning up the radio don’t work.
Recovery after call:
Fit your recovery to your chronotype:
Night owls: take a longer recovery nap the morning after call.
Morning larks: keep the post-call nap short and go to bed early.
Add extra nocturnal sleep time for 2 to 3 nights after an overnight shift. Pilots plan recovery over 2 or more days after long-haul operations.
Avoid a long, late-afternoon nap that pushes your bedtime past your usual time.
Ongoing fatigue management
Watch for signs of cumulative fatigue, and be wary of relying on coping measures / stimulants (coffee).
If you’re still sleepy despite enough sleep opportunity, or you snore, have witnessed apneas or have trouble sleeping on days off, talk to your physician. An underlying sleep disorder may be part of the problem.
Fatigue is a shared responsibility:
Residents: self-assess, declare fatigue, support colleagues who disclose it, and report fatigue-related incidents.
Programs and leaders: treat FRM as a priority, involve trainees in fatigue plans, and provide places to rest and nap.
Resources
Fatigue Risk Management Toolkit for Residents, Leaders, and Policy Makers (RDoC / Royal College)
McKenna H, Wilkes M. Optimising sleep for night shifts. BMJ 2018;360:j5637 (with visual summary)
PARO for duty hours under your collective agreement, and the PARO 24/7 Helpline
Your PGME office’s fatigue risk management policy and resident wellness program
