Post-operative sleep disturbance: causes, factors and effects on outcome.

Post-operative sleep disturbance, with suppression of rapid eye movement sleep and slow wave sleep followed by a subsequent rebound, seems to be related to the magnitude of trauma and thereby to the surgical stress response. In this context, cortisol, autonomic stimulation, and certain cytokines may lead to abnormal sleep. Furthermore, the environment, pain and the administration of analgesics seem to be important factors in the precipitation of sleep abnormalities. Post-operative sleep disturbance may contribute to the development of episodic hypoxaemia, haemodynamic instability and altered mental status, all of which have an influence on post-operative morbidity and mortality. Prevention or reduction of the post-operative sleep disturbance may be achieved by minimizing surgical trauma, changing the conventional nursing procedures, avoiding opioids and treating pain with non-opioid analgesics, although none of these methods has been thoroughly studied. Post-operative sleep disturbance represents an important research field, since it may have a significant adverse impact on post-operative outcome.