(Don't Be) Asleep at the Switch
By Frederick E. Tilton; FAA Federal Air Surgeon
Reprinted with permission from FAA Safety Briefing
On a daytime flight, a commercial airliner with three crewmembers and 40 passengers flew past its destination airport after both the captain and first officer fell asleep. The pilot awoke and landed safely. NTSB determined the captain’s undiagnosed obstructive sleep apnea (OSA) was a factor in this incident.
Not Just an Inconvenience
Apnea is a medical term that means “being without respiration.” OSA is characterized as a repetitive upper-airway obstruction during sleep, as a result of narrowing of the respiratory passages.
OSA is recognized as a major contributor to many health-related ailments. According to some estimates, OSA affects 4-7 percent of middle-aged people, most of who are overweight and have higher deposits of fatty tissue in their respiratory passages. Gravity can cause this tissue to obstruct a person’s airway.
Snoring can result when the airway is partially obstructed. With further tissue obstruction of the airway, there may be complete occlusion. Whether the obstruction is partial (hyperpnoea) or total (apnea), the person struggles to breathe and is aroused from sleep. These sleep interruptions are often unrecognized, even if they occur hundreds of times a night. A real danger is OSA sufferers may not recognize the condition and may only know that they typically wake up feeling sleepy and tired.
Losing sleep is more than an inconvenience. Sound sleep is essential for good health and clear mental and emotional functioning. OSA is also associated with reduced blood-oxygen levels feeding the brain, which, of course, is a major health concern. Repetitive decreases in blood-oxygen levels associated with OSA may eventually increase blood pressure, strain the cardiovascular system, and increase the risk of heart attack or stroke.
The implications for pilots are significant, because people with mild-to-moderate OSA can show performance degradation equivalent to 0.06 to 0.08 percent blood-alcohol levels, which is the measure of legal intoxication in most states.
OSA Symptoms, Diagnosis, and Treatment
Symptoms suggesting OSA include: loud and excessive snoring; difficulty concentrating, thinking, or remembering; daytime sleepiness, fatigue, and the need to take frequent naps; and headaches and irritability.
The only way OSA can be diagnosed is through a sleep study. Once diagnosed, OSA is highly treatable, either with surgery or non-surgical approaches. Non-surgical approaches include:
- Making behavioral changes, such as a different sleeping position or environment, and a diet to lower body fat.
- Using dental appliances that thrust the lower jaw forward and open the airway.
- Using a Continuous Positive Airway Pressure (CPAP) machine or Bi-level Positive Airway Pressure (BiPAP) machine. These machines use air pressure to hold tissues open during sleep. The newer machines—and the one required by the FAA—have a computer device that keeps track of the number of hours and days that you are compliant.
- Taking medications approved by the FAA.
Surgical methods can be significant and do not always succeed. They should be used only after nonsurgical methods have failed. If you experience one or more symptoms of OSA, consult a physician. OSA treatment has a high success rate and, if your OSA is treatable, you can maintain your airman medical certificate and continue to enjoy aviation.
Dr. Tilton received both an M.S. and a M.D. degree from the University of New Mexico and an M.P.H. from the University of Texas. During a 26-year career with the U.S. Air Force, Dr. Tilton logged more than 4,000 hours as a command pilot and senior flight surgeon flying a variety of aircraft. He currently flies the Cessna Citation 560 XL