Opioid-related side effects: Postoperative ileus, urinary retention, nausea and vomiting, and shivering. A review of the literature

Opioids are widely used in clinical anesthesia. However, side effects include postoperative nausea and vomiting, shivering, ileus, and urine retention and are specifically discussed here. From the available evidence, it appears that the use of opioids is strongly associated with impaired gastrointestinal motility. Therefore, to prevent postoperative ileus, the use of opioids should be minimized and opioids should be replaced by other drugs. With regard to the risk of postoperative urinary retention, one problem is the lack of standardized definition. Nevertheless, the use of opioids is clearly an important risk factor. Postoperative nausea and vomiting have high incidences. Even if the mechanisms are partially understood, opioid-sparing strategies have been shown to decrease its incidence. Finally, the problem of postoperative shivering has been, at least partially, solved by the avoidance of (high doses) remifentanil and the use of alpha-2 agonists. In conclusion, postoperative urinary retention, postoperative ileus, nausea and vomiting, and shivering are complex problems seen after surgery. Management is possible, but prevention is possible with the avoidance of high doses of intraoperative opioids, conjointly to opioid-sparing techniques.