Catecholamine excretion in A-10 pilots.

Catecholamine excretion was determined for 15 USAF pilots during surface attack training in the A-10 aircraft. Timed urine samples were used to determine excretion rates of epinephrine and norepinephrine during basal conditions, during five sorties performed in high-realism simulators, and during six actual flights. Catecholamine excretion was significantly elevated (p < 0.05) over basal rates during all 11 training sorties; therefore, it was concluded that A-10 conversion and surface attack training results in a significant stress response in the subjects. The stress response experienced in the simulator diminished across trials; the stress response from aircraft flights remained steady through all sorties monitored. The relative proportions of epinephrine and norepinephrine remained similar across all but the final sorties in both the simulator and the aircraft. These occasions were typified by increased norepinephrine and decreased epinephrine excretion rates.