Physiological recovery from night-call duty - a field study of physicians

Sammanfattning: Abstract Physicians’ work on night-call entails long and stressful working hours with high demands and disrupted sleep. Incomplete recovery is considered to be the most important link between acute physiological stress reactions, shift work and chronic health effects. Mental and physiological activation naturally accompanies night-call duty, but the crucial issue, from a health perspective, is whether the activation is sustained post-call. Studies of physicians show that night-call duty can be detrimental to subjective health and performance. However, less is known about the physiological effects of working on night call, and whether the effects of such duty differ across medical specialities. For anaesthesiologists on night-call, the mental load of constantly handling patients with life-threatening conditions may have a greater impact on their recovery compared with other specialists. In the present field study 19 anaesthesiologists were compared with18 paediatricians and ear, nose, and throat surgeons. They all had 16-hour night-call duties at a university hospital. The aims were to determine whether a sufficient physiological recovery would be attained within 1-3 days after night-call duty, and whether recovery patterns differed across medical specialities. Several physiological systems were monitored by repeated measures on ordinary daytime work, during night-call duty and during post-call. Cortisol was analysed in saliva, and other metabolic factors were analysed in blood samples. Sleep was monitored with actigraphy and ambulatory electrocardiographic recordings were used to measure heart rate variability (HRV), to determine autonomic balance. The results suggested no general metabolic change after night-call duty. Recovery sleep after night call was considered sufficient, but sleep after daytime work was unexpectedly short. HRV patterns did not indicate a deficient recovery, but possibly a higher physiological stress level in anaesthesiologists. The 16-hour night-call schedules seemed compatible with a short-term physiological recovery within two days after night-call duty, but the limited sleep after ordinary daytime work may constitute a long-term health concern. All these results contribute to our knowledge of how to plan sustainable night-call working schedules, and further investigation is needed to determine whether these results can be generalized to other work settings and specialists.