C.A. DeJohn, S.J.H.Veronneau, J.R. Hordinsky
FAA Civil Aerospace Medical Institute
P.O. Box 25082 Oklahoma City, OK 73125
and
Joan Garrett
MedAire, Inc.
1301 E. McDowell Rd. Suite 101
Phoenix, AZ 85006

Introduction
There is no method of monitoring the incidence of inflight medical emergencies (IMEs) because airlines are not required to report them. An FAA survey conducted from 1986 to 1988 found 2,322 IMEs, averaging approximately 3 per day (annual diversion rate approximately 8% of IMEs). In a more recent FAA survey, 2,388 IMEs resulted in 190 diversions over a 3 year period ending in 1993 (also approximately 8% annual diversion rate).

Methods
In this survey, IMEs aboard selected domestic U.S. air carriers were monitored from October 1, 1996 to September 30, 1997. IMEs were studied to determine the categories occurring most frequently, the diversion rate, and the categories that had the greatest probability of resulting in a diversion. The adequacy of inflight medical care was evaluated by assessing inflight patient response and postflight outcomes.

Results
Preliminary results indicate that vasovagal and cardiac cases occur most frequently, followed in order by neurological, gastrointestinal, and respiratory emergencies. Cardiac emergencies account for the most diversions, followed in order by neurological, respiratory, and vasovagal cases. The diversion rate for cardiac cases is the highest, followed in order by neurological, obstetrical, vascular, and respiratory emergencies. Physicians responded to IMEs approximately half of the time, while nurses respond about a third of the time. The medical kit was used in approximately half of IMEs. The stethoscope and sphygmomanometer were used over 700 of the time the kit was used, and nitroglycerin was used about five times as often as epinephrine or diphenhydramine.

Conclusions
In-flight medical intervention resulted in an improvement in patient condition over 80% of the time. Physicians were the most frequent responders to requests for assistance and achieved a good result in more than 95% of cases where the medical kit was used.