It’s easy to see from all that information how critical sleep is and understand the link between quality sleep and our health, intellect, and safety. This month let’s talk about some abnormal sleep patterns that can prevent you from getting a good night’s sleep and interfere with the crucial nighttime biochemical chores that should be going on in our heads while we rest that I outlined in the last post. It’s important for pilots and our safety in the sky to understand these abnormalities and also to understand what to do about them.
The most common abnormal sleep pattern is simply not getting enough sleep, generally known as insomnia. The word comes from the Latin root somnus (sleep) preceded by the negative, in, and it’s this little two-letter detail that drives us all crazy. Insomnia is the generic term for a constellation of symptoms, and about one in three adults suffer one or more of these symptoms to some degree. There are three components that make up insomnia; trouble falling asleep, staying asleep, and getting good quality sleep.
Insomnia can be related to a bunch of different factors like daytime psychological stresses, anxiety, poor sleeping environment, irregular sleep schedule, time zone changes, shift work, or excessive mental, physical, or chemical stimulation. Data shows that simple lack of daytime physical and mental activities correlates with poor sleep patterns. There are also a number of medications that lead to insomnia, including many common over-the-counter meds like cold remedies, and lots of items in our diet that have high levels of caffeine, all of which interfere with sleep patterns. Check the labels to find out which ones are the worst offenders, and stay away from high-caffeine content beverages and foods in the evening as sleep time approaches. Just like we talked about a few months ago regarding individual variation in alcohol metabolism, the same holds true for caffeine metabolism—its stimulus effects can hang around in your system anywhere from 2 to upwards of 12 hours depending on your genetics.
Another common reason people don’t get a good night of rest is Obstructive Sleep Apnea (OSA). Snoring is the hallmark symptom of OSA and in the medical world OSA is also known as “Pickwickian syndrome.” It’s named after Joe, the obese old guy in Charles Dickens’ 1836 novel The Pickwick Papers, who eats too much, falls asleep all the time, and bothers everyone with his loud snoring, all the classic symptoms of OSA. This is a big deal and the FAA publishes an OSA guide for AMEs, which states clearly that, “sleep apnea has significant safety implications due to cognitive impairment secondary to the lack of restorative sleep and is disqualifying for airman medical certification.” It goes on to list the number of very serious consequences of OSA that include “excessive daytime sleepiness, cardiac arrhythmias, sudden cardiac death, personality disturbances, refractory hypertension, and cognitive impairment.” In order to qualify for your medical certification the FAA requires a special issuance and clearance of the OSA protocols for evaluation.
About 25–30% of men and 15% of women suffer from some degree of OSA. It can have a lot of causes but all lead to the same issue; an obstructive process that interferes with nighttime breathing triggering patients to have long pauses (apnea) between taking a breath while supine. The result is that the airway collapses, breathing stops, and hypoxia drives your brain to wake you up from sleep to take another breath. The anatomy of OSA is well known and is instigated by tissue in the back of the throat that blocks the upper airway when you generate negative pressure to inhale. The incidence of OSA is closely related to body habitus and weight, going up as high as 55% in obese patients due to neck mass and fat content. It’s also related to weakness of pharyngeal musculature, which can happen from illness or secondary to a stroke. Another cause can be due to anatomical variations in the size and shape of structures in the back of the throat like the tonsils and adenoids. When OSA occurs regularly, restful sleep is impossible. There is a variation of OSA called “central sleep apnea“ (CSA) that can happen when the breathing center in the brain stem doesn’t work correctly. OSA and CSA are diagnosed with sleep studies that your doc can order.
There are several treatments for OSA that start simple and get pretty complicated. The simplest are a variety of lifestyle changes such as weight loss, throat exercises, quitting smoking and alcohol use, and changing sleep position that have a place in the treatment of mild to moderate OSA. There are also mouth appliances to keep your jaw forward during sleep; some can be bought at the corner drug store, and others are custom-made for you by a dentist or sleep specialist. Going up the complexity ladder, there are also a variety of machines that blow positive pressure air into your nose and mouth to keep your upper airway open during sleep. The gold standard is known as CPAP (continuous positive airway pressure). It works great for OSA but is not as effective in CSA (central sleep apnea). For patients who can’t tolerate CPAP there is a less burdensome device known as BiPAP (bilevel positive airway pressure). When things get really serious there are several surgical procedures that an ENT doc could do like resection of the obstructing tissue (tonsils and adenoids), jaw repositioning, tongue surgery, and nasal tissue resections. Another available option is implanting devices that stimulate the nerves of the upper airway during sleep. Sleep apnea is important to diagnose and treat since, just like the FAA says, it leads to multiple other medical problems like high blood pressure and pulmonary hypertension (high blood pressure in the lungs), stroke, hypoxia, and higher overall cardiac death rates. The American Academy of Sleep Medicine publishes a really thorough guide to adult OSA that’s linked here. The takeaway from all of this is sleep apnea is a big deal for pilots and can ruin your health and disqualify you from getting your medical certificate.
There are other less common sleep disorders that also interfere with the brain doing all its important nighttime work. One of them is inadequate REM sleep, known as “non-rapid eye movement” (NREM) sleep, which causes episodes of incomplete awakening from sleep and significant daytime distress and dysfunction. Another is “sleepwalking” (medically known as “somnambulism,” literally ambulating while asleep), and as the name implies involves repeated episodes of getting out of bed and walking around while still asleep. About 30% of people have experienced sleepwalking at some time in their lives and it leads to all the same daytime issues. Even less common is a disorder called “narcolepsy,” which causes rapid transitions between sleep and wake that interfere with that all-important phase of REM sleep.
Serious side effects from poor sleep habits are a real problem for another common group of people who have diabetes. This is because restful sleep is particularly important to maintain normal glucose levels. Stress induced by poor sleep results in cortisol and stress hormone release, and those two chemicals will impede insulin release and transport of glucose needed for energy. This results in high serum glucose levels and elevated Hemoglobin A1c that are so important for diabetics to control.
All these consequences of non-restful sleep make it clear how important a good night’s sleep is to our health, safety, and well-being. Next month, we’ll wrap up our deep dive into sleep with a look at helpful tips you can use to get that critical full night of restorative sleep so you can be sharp during the day and safe in the sky. Just don’t count on a few cocktails to give you a good night’s sleep since alcohol does not provide you with a restorative sleep pattern and can also act as a stimulant and actually decreases sleep quality. Until then, sleep well and fly safe!
