Knowledge of
postoperative nausea and vomiting (
PONV) risk factors allows anesthesiologists to optimize the use of prophylactic regimens. Modern
PONV risk research began in the 1990s with publication of studies using logistic regression analysis to simultaneously identify multiple independent
PONV predictors and publication of meta-analyses and systematic reviews. This literature shows that female gender post-puberty, nonsmoking status, history of
PONV or
motion sickness, childhood after infancy and younger adulthood, increasing duration of surgery, and use of volatile
anesthetics,
nitrous oxide, large-dose
neostigmine, or intraoperative or postoperative
opioids are well established
PONV risk factors. Possible risk factors include history of
migraine, history of
PONV or
motion sickness in a child's parent or sibling, better ASA physical status, intense preoperative anxiety, certain ethnicities or surgery types, decreased perioperative fluids,
crystalloid versus
colloid administration, increasing duration of
anesthesia, general versus
regional anesthesia or sedation, balanced versus total IV
anesthesia, and use of longer-acting versus shorter-acting
opioids. Early-phase menstruation,
obesity and lack of supplemental
oxygen are disproved risk factors. Current risk scoring systems have approximately 55%-80% accuracy in predicting which patient groups will suffer
PONV. Further research examining genetic and under-investigated clinical patient characteristics as potential risk factors, and involving outpatients and children, should improve predictive systems.