Prediction of distress for individuals wearing industrial respirators.

The purpose of the investigation was to evaluate the effectiveness of trait anxiety in predicting respiratory distress resulting from heavy physical work performed while wearing an industrial respirator. Spielberger's trait anxiety scale was administered to 45 male volunteers in order to identify individuals with elevated trait anxiety. This testing was followed by a pulmonary function test, resting 12-lead electrocardiogram (ECG), and an exercise ECG. Individuals with cardiovascular and/or pulmonary impairment did not continue with subsequent tests. The subjects next completed three treadmill tasks varying in intensity from 35% to 80% of VO2max, and each trial lasted for 10 minutes. Twenty-five of these individuals performed the exercise tasks while wearing a self-contained breathing apparatus (SCBA) in the demand mode, whereas the remaining 20 subjects used a pressure-demand SCBA. The reason for terminating exercise was classified as respiratory or non-respiratory on the basis of self-report responses on a 7-point dyspnea scale, as well as general responses concerning muscular fatigue and respiration. It was predicted, based upon trait anxiety scores, that six individuals would have respiratory distress, and five (83%) of these predictions were correct. It was also predicted that 39 of the 45 subjects would not experience distress and 38 (97%) of these predictions were correct. It was concluded that objective measures of trait anxiety can be used to identify those individuals who are most likely to experience distress while wearing an industrial respirator and performing heavy physical exercise.