European isolation and confinement study. Workload and stress: effects on psychosomatic and psychobiological reaction patterns.

Six healthy males, the EMSInauts, were isolated in hyperbaric chambers for a period of 28 days at 5-msw overpressure. During that period they had to carry out meaningful operational and research tasks in addition to monitoring their psychological and physiological reactions. The actual workload was evaluated and compared with the planned workload, and its effects on symptomatology and psychobiology. The perceived workload and its effects on psychosomatic symptomatology and on some biological indices were monitored. Thus it was possible to evaluate how the workload carried during 4 weeks of isolation affected the psychological and biological well-being of the six EMSInauts. The following three types of assessments were performed: 1. Workload assessment: The objective workload was calculated based on the schedule which was revised daily, and the actual load calculated by the commander. A workload questionnaire was administered daily after each working session. 2. Psychosomatic assessment: Morning and evening questionnaires were administered daily. The state of health and of anxiety were also evaluated. 3. Biological indices: Cortisol, testosterone, adrenalin, and noradrenaline were determined once a week. In addition, cardiac activity was monitored every day. The workload assessment showed that on the average the planned workload was accomplished in slightly less than the scheduled time. The workload was not perceived as severe in terms of cognitive, emotional, and physical load. The group rated the support received from each other and from the mission control personnel as average, with minor changes during the isolation period. They gave a high rating to the amount of control they had over their activities. Fatigue and tension were scored in the middle range. The psychosomatic assessment showed that there were few symptoms, and these were mostly of low severity. The most common symptom was general fatigue. Furthermore, minor dizziness, headache and light tremor was in some cases reported. The sleep quality was good, but complaints about poor sleep increased somewhat with the passing of time. Few and mostly minor health problems were experienced during isolation. Only one EMSInaut had to miss one day of work due to a bout of flu. The state of anxiety was below that of the general population throughout the isolation period. The biological indices used showed no evidence of stress from the workload handled during the isolation period. The level of the "stress hormone" cortisol actually decreased during isolation. The adrenalin excretion, which tends to go up during acute stress, remained unchanged during this period. Neither was there any evidence of changes in cardiac activity throughout the isolation period.(ABSTRACT TRUNCATED AT 400 WORDS)