Pilot fatigue is one of the least studied and unreported problems in aviation. Sleep is the number one remedy for fatigue, both mental and physical. Pilots and non-pilots take sleep for granted and feel they can always make it up on their days off and weekends. This unsubstantiated concept of “catching up on your sleep” is a trap that could potentially lead to airplane mishaps. In an article titled "Fatigue in Aviation," by John A Caldwell, Travel Medicine and Infectious Disease, May 2005 Volume 3, Issue 2, pages 85-96, statistics indicate that at least 4-8% of aviation accidents are due to fatigue.
Every pilot hopefully uses the IMSAFE checklist. I point out the F in IMSAFE means Fatigue. Before every flight lesson or flight, my students will be asked how much sleep they received. If they say less than 7 hours I go into a mindset of being extra vigilant in how they might perform their maneuvers, preflight planning, cross country decisions or making a go-no-go decision strictly on the amount of sleep they received. Their amount of caffeine intake will not increase their performance to make up for any lost sleep. They will still be fatigued but just more wide awake.
There is a reason why I use 7 hours of sleep as a standard for myself and my fellow pilots and students. This is the criterion the Centers of Disease Control (CDC) uses as their standard. They have broken down the areas of the US who get greater than 7 hours and less than 7 hours of sleep. The category of sleep the CDC uses is Short Sleep Duration. I am quoting data from a report on June 2, 2016 from the CDC. The largest area of Short Sleep duration is east of a line from the Upper Peninsula of Michigan down to Alabama. The people surveyed in this section of the United States had the highest percentage of less than 7 hours of sleep ranging between 38 and 44%. Kentucky had the highest percentage of sleep deprived people. FITBIT conducted a study from March through December 2017, that analyzed 6 billion nights of their customers' sleep. They found that if you go to bed at the same time every night throughout the week that you had the best sleep patterns for a healthy lifestyle. If you stayed up later by even 30 minutes and slept in later on the weekends, your sleep quality was worse. They also found that as we age the amount of deep sleep diminishes.
The CDC have also found that people who have short sleep duration would be more likely to report higher rates of obesity, be physically inactive and smoke. Chronic conditions that were reported by short sleep duration folks included coronary heart disease, stroke, asthma, chronic obstructive pulmonary disease, cancer, arthritis, depression, chronic kidney disease and diabetes.
To put it simply, sleep rests, restores and energizes the brain. There are 5 stages of sleep that include Stage 1 and 2 for light sleep, 3 and 4 for deep sleep and Rapid Eye Movement (REM) sleep. During 3 and 4 (Deep Sleep) the body is repairing muscles and tissues, stimulates growth and development, boosts your immune system and builds energy stores for the next day. With 5 or 6 REM cycles a night, the brain gets energized.
Some non-medication recommendations for getting to sleep are a cut off time of 5 o’clock for caffeinated products like coffee, tea and soda. Watching TV or reading a book right before sleep has been shown to cause decreased sleep time unless you are totally exhausted from not getting sleep the night before. Having a glass of warm milk or chamomile tea has been shown to help.
The most used over the counter sleep medication is diphenhydramine (Benadryl®). Diphenhydramine is an antihistamine that is normally used for severe allergic reactions and itching. The normal dose for sleep is 50 mg at bedtime. Diphenhydramine stays in the body for a very long time. The amount of time it takes for half of the dose to be eliminated has been reported as 8 to 12 hours. When you wake up after a dose of Diphenhydramine you may have a dry mouth, possible urinary retention, may have an episode of sleep walking during the night and still be drowsy. This does not sound like a state you should be in before flying. Us folks in pharmacology will calculate how long it will take for diphenhydramine to be completely eliminated from the body. The calculation is five times the half life, which is 5 times 12 or 60 hours (2.5 days). This is the reason why you will see the FAA recommending holding off flying until 60 hours have passed after the last dose of diphenhydramine.
Melatonin is one of the best sleep aids available, as its onset of action is one hour and will usually give 4-6 hours of sleep with no hangover. It was the original sleep aid for jet lag. Based on studies, the recommended dose is 10-12 mg one hour before bedtime. The FAA has cautioned that the melatonin wait time after the last dose taken is 24 hours.
Everyone knows about Zolpidem (Ambien®) as a sleep aid. Ambien®, Ambien CR® and Intermezzo® are on the FAA safe medication list with the caveat that it can be taken 1-2 times a week with a 24 hour wait time post dose for Ambien® and Ambien CR® and 36 hours for Zolpidem sublingual (Intermezzo®). It also has my favorite side effect that is not well known, weight gain. It causes sleepwalking and people will weigh themselves in the morning and cannot understand why they gain weight. They have been sleepwalking to the refrigerator on a regular basis. Eszopiclone (Lunesta®) works the same as Ambien® and the wait time is 30 hours. Ramelteon (Rozerem®) works very similar to Melatonin and the wait time is 24 hours. Zaleplon (Sonata®) has the shortest wait time of 6 hours. If you have occasional problems getting to sleep and must fly this medication may be a good choice for time between dose to sleep to flight. I must caution that most insurances do not cover these sleep aids and they can get very pricey.
You should have a sleep pattern plan for yourself. As mentioned above you should go to sleep at the same time every day and get greater than 7 hours. Going to sleep after a bad day at work and reliving those thoughts before sleep may lead to less than adequate amounts of quality sleep for that next day flight. If sleep aids are necessary, make sure you understand how long you must wait after the sleep aid dose and what effects you may feel after getting up. Always take this into account as part of your IMSAFE checklist. If you need to take a prescription sleep aid make sure you check with the AOPA’s FAA Safe Medication Database before taking or check while in your physician’s office.
