Anti-Emetic Dexamethasone and Postoperative Infection Risk: A Retrospective Cohort Study (Original Papers) (Report‪)‬

Postoperative nausea and vomiting (PONV) affects approximately 30 to 70% of patients in the first 24 hours after general anaesthesia (1,2). It carries substantial morbidity, including delayed discharge and unplanned admission following day surgery (3). It is one of the complications most feared by patients (4). The factors which increase the risk of PONV are now well characterised (1) and this, coupled with increasing appreciation of its importance (5), have led to a focus on prophylaxis and effective treatment. While several predictive models are available (2,6,7), none are absolute (1). Hence, consensus guidelines have been published and recently updated (8,9). Once anaesthetic technique has been optimised to reduce PONV, many different anti-emetics can be used to reduce the risk of developing PONV and to treat it once established (9,10). The use of single anti-emetic agents prophylactically has been found to reduce the risk of PONV by approximately 26% and, when further anti-emetics are added, can cumulatively reduce the risk by up to 70% (11), particularly in high-risk populations. Dexamethasone is an anti-emetic that is used as a single dose prophylactically during surgery in patients at high risk of developing PONV (11). It has a short plasma half-life, but a biological and effect half-life of up to 72 hours, and appears to be particularly effective against late PONV. There are many advantages in using dexamethasone over other anti-emetics including cost, duration of action and tolerability, although its exact mechanism of action as an anti-emetic is unclear.