Postoperative nausea and vomiting (PONV) remains one of the most common side effects following anesthesia and surgery, with reported incidences ranging from 20% to 30% in the general surgical population and exceeding 70% in high-risk groups. Beyond discomfort, PONV causes delayed recovery, unanticipated hospital admissions, wound dehiscence, electrolyte disturbances, and increased healthcare costs. Dexamethasone is widely used for prophylaxis due to its efficacy, favorable safety profile, and cost-effectiveness.
Dexamethasone, a long-acting corticosteroid with potent anti-inflammatory properties, is typically administered intravenously at induction of anesthesia in doses ranging from 4 mg to 8 mg in adults. Multiple proposed antiemetic mechanisms include prostaglandin synthesis inhibition, serotonin reduction, nucleus tractus solitarius modulation, and surgical inflammatory response attenuation.
Research demonstrates dexamethasone significantly reduces both early and late PONV compared with placebo, particularly in reducing vomiting. Its benefits amplify when combined with other agents like 5-HT3 antagonists or neurokinin-1 receptor antagonists. Beyond antiemetic effects, dexamethasone reduces postoperative pain and opioid consumption, and improves recovery parameters in thyroidectomy and laparoscopic procedures.
Transient hyperglycemia represents the primary safety concern, especially in diabetic patients, though typically self-limited. Concerns regarding impaired wound healing and increased risk of surgical site infection have not been substantiated in the majority of studies evaluating single-dose administration. Optimal dosing involves 4 mg for lower-risk patients and 8 mg for higher-risk groups.