UNDERSTANDING POST-OPERATIVE FATIGUE

Abstract

Postoperative performance characteristics of the CNS, cardiovascular, respiratory and muscular systems in man have received little investigative attention, despite the well known syndrome of postoperative fatigue. The impairment in perception and psychomotor skills that results from caloric restriction, bedrest, sedation and sleep deprivation suggests that a similar deficit may occur after surgical procedures. After a simple elective surgical procedure, maximal O2 uptake decreases and the adaptability of heart rate to submaximal workloads is impaired. Similar deleterious effects on cardiorespiratory performance were documented with starvation and bedrest. Maximal muscular force of contraction is also impaired by caloric restriction and bedrest, suggesting that similar effects may be seen in the postoperative state. A better understanding of the syndrome of postoperative fatigue could be achieved by a descriptive analysis of physiologic performance postoperatively. Such descriptive data could form the basis for objective evaluation of therapeutic measures intended to improve performance, such as nutritional supplementation and pharmacologic intervention. The observation that exercise with the patient in the supine position may decrease the impairment in maximal aerobic power otherwise expected in immobilized patients suggests that controlled exercise therapy may be of value in reducing physiologic impairment postoperatively.