Short-term catecholamine response to psychological stress.

The recent development of radioenzymatic assays for plasma catecholamines and of highly portable nonobtrusive blood withdrawal pumps makes possible the investigation of the physiological response to actual stress. However because the half-life of plasma catecholamines is so brief, meticulous care must be taken to obtain blood samples consistently vis-a-vis the stress immersion experience. These points are demonstrated in a study of ten young physicians under the stress of public speaking. Plasma epinephrine levels differ significantly between the initial moments of public speaking and the middle moments of speaking. These differences are large enough to affect the conclusions reached in comparing public speaking values with baseline values.