Fatigue and cardiorespiratory function following abdominal surgery.

Subjective feelings of fatigue were assessed before operation and 10, 20 and 30 days after uncomplicated elective abdominal surgery in 16 otherwise healthy patients, using a constructed fatigue scale model. In addition, all patients had an orthostatic stress test performed at the same times. Six of the patients also underwent a bicycle ergometer test measuring heart rate and oxygen consumption. Subjective feelings of fatigue were increased (P less than 0.01) at all three postoperative observations, and only 5 of 16 patients returned to their preoperative level. The increased subjective feeling of fatigue correlated positively (RS = 0.53, P less than 0.001) with the increased pulse rate seen during orthostatic stress after operation. Heart rate was about 5 per cent higher (n.s.) after operation when bicycling at the same work loads, while oxygen consumption decreased by about 2 per cent (P less than 0.01) at all three postoperative bicycle tests. It is concluded that even electric uncomplicated abdominal surgery is followed by a pronounced feeling of fatigue, which may persist 1 month after surgery in about one-third of patients. The fatigue scale model seems applicable for future studies on the pathogenesis and treatment of the postoperative fatigue syndrome.