Riding (High) into the danger zone: a review of potential differences in chemical exposures in fighter pilots resulting from high altitude and G-forces

ABSTRACT

Introduction: When in flight, pilots of high performance aircraft experience conditions unique to their profession. Training flights, performed as often as several times a week, can expose these pilots to altitudes in excess of 15 km (~50,000 ft, with a cabin pressurized to an altitude of ~20,000 ft), and the maneuvers performed in flight can exacerbate the G-forces felt by the pilot. While the pilots specifically train to withstand these extreme conditions, the physiologic stress could very likely lead to differences in the disposition of chemicals in the body, and consequently, dangerously high exposures. Unfortunately, very little is known about how the conditions experienced by fighter pilots affects chemical disposition.

Areas covered: The purpose of this review is to present information about the effects of high altitude, G-forces, and other conditions experienced by fighter pilots on chemical disposition. Using this information, the expected changes in chemical exposure will be discussed, using isopropyl alcohol as an example.

Expert opinion: There is a severe lack of information concerning the effects of the fighter pilot environment on the pharmacokinetics and pharmacodynamics of chemicals. Given the possibility of exposure prior to or during flight, it is important that these potential effects be investigated further.

KEYWORDS:

• Altitude
• flight
• G-force
• gravity
• isopropanol
• isopropyl alcohol
• pharmacodynamics
• pharmacokinetics
• pilot

Article highlights

• Pilots of high performance aircraft are required to track their position and attend to a litany of gauges, instruments, and alerts, all while piloting an aircraft under unique and difficult conditions, meaning any unexpected hindrance to their cognitive performance could be extremely detrimental

• Knowledge of the effects of altitude and G-forces on pharmacokinetics (PK) and pharmacodynamics (PD) is extremely limited

• Research available on ethanol in those conditions may provide insight into how the exposure to and effects of isopropanol (isopropyl alcohol, IPA), a potential contaminant in the breathing air supply, may be affected

• While there is evidence of altered PK and PD under flight conditions, it is sparse, and occasionally conflicting

• Certain studies are recommended in order to better elucidate effects of altitude and G-forces, in particular, on isopropanol distribution and cognitive impact

This box summarizes key points contained in the article.

Declaration of interest

MW Linakis, CMT Sherwin and KM Job authors received compensation from the USAF for time spent preparing this manuscript. HA Pangburn and DK Ott are affiliated with the USAF who funded this manuscript. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This work was supported by a contract from the United States Air Force (USAF)