What are the risk factors for postoperative nausea and vomiting (PONV)?

What are the risk factors for postoperative nausea and vomiting (PONV)?

Contributing factors to a higher incidence of PONV are young age, female gender, large body habitus, history of motion sickness or previous PONV, anxiety, and concomi-tant disease.

There is no evidence that any anesthetic technique or drug regimen results in a lower incidence of postoperative nausea and vomiting, except for propofol, which has intrin-sic antiemetic properties. There is, however, little benefit if propofol is used only as an induction agent. Conflicting evi-dence exists regarding nitrous oxide. Similarly, claims of an increased incidence of PONV with higher opioid doses are questionable, and the incidence of PONV appears to be similar with different opioids.

The procedure performed has a major influence on the incidence of PONV, with the highest incidence in patients undergoing laparoscopic surgery or head and neck surgery involving the oropharynx, inner ear, or eyes (especially strabismus correction). A longer duration of the surgical procedure is also associated with a higher risk of PONV.