The IMSAFE checklist (Illness, Medication, Stress, Alcohol, Fatigue and Emotion) is a remnant from their earliest days of flight training for many pilots and continues as a helpful mnemonic to self-certify their fitness for flight.
Following his successful presentation last year in Nashville, CJP Chair and former US Air Force flight surgeon Blake Curd returned to CJP 2024 for an in-depth discussion of both the benefits of IMSAFE and the importance of going beyond those six letters to consider how common behaviors and life factors can influence our health.
For example, many pilots may not know how alcohol can not only impair their abilities in the near-term through the effects of intoxication, but also by exacerbating chronic sleep apnea and reducing O2 blood saturation levels, contributing to hypoxic effects.
“Hypoxia, by definition, is an inadequate oxygen supply to the tissues,” he said. “The ratio of oxygen to other gases we breathe in remains at 21 percent regardless of altitude; however, the molecules are further spread around and are not as densely packed as they are at sea level, so the pressure of oxygen in the lungs that cross the alveoli – those little air sacs that move O2 into the blood – do not have the pressure that they need to adequately oxidize.”
Curd offered several examples demonstrating hypoxic effects, including a pair of USAF videos showing airmen passing out in pressure chambers. He also played recorded ATC communications with the flight crew of a Lear 25 on a cargo run from Virginia to Michigan who survived a severe hypoxic episode. The first officer passed out, and the captain was just barely cognizant of their situation to respond to ATC commands and descend the aircraft to a breathable altitude, saving their lives.
“Shortness of breath is a common early warning indicator of hypoxia,” Curd continued, “along with tachycardia and tachypnea, or rapid, shallow breathing. If you’ve not had an opportunity to get the chamber, you should do so to understand what your own hypoxia symptoms are.”
Another less-commonly considered hindering factor on our flying health is the side effects from semaglutide (Ozempic) and GLP-1 inhibitor medications originally intended for treatment of diabetes but increasingly used for weight loss.
“A glucagon-like peptide mimics glucagon in your system and raises blood sugar,” Curd explained. “It causes glucose production of the liver and causes your pancreas to secrete insulin. It actually increases your energy expense and has been shown to be beneficial in patients that have cardiac dysfunction” – all in addition to appetite suppression and weight loss.
“We don’t know the long-term side effects,” he continued. “The studies were done with thousands of people, not with tens of thousands or millions of people over a number of years. Mostly, it seems okay, although there have been some reported complications with the optic nerve, causing people to have vision disturbance and vision loss.”
That emphasizes the importance of taking time to determine the side effects from any new medications before returning to the flight deck. Curd also cautioned pilots from using marijuana and CBD oils that, while now legal in many states, remain banned at the federal level and by FAA regulations.
“We had a state patrol dog come in once,” Curd recounted from his time serving in the South Dakota State Senate. “They put down a plate of pure hemp on one side and marijuana on the other. The dog hit on both of them, so the dog’s nose knows that both contained THC. So, if you are rubbing a bunch of this on your joints or take the liquid, it’s possible it can show up in your blood and in hair samples.”