Optimal Prophylactic Regimen for Postoperative Nausea and Vomiting

Introduction to PONV Prophylaxis

A multimodal approach combining ondansetron 4 mg and dexamethasone 4-5 mg is the recommended prophylactic regimen for postoperative nausea and vomiting (PONV), as this combination provides superior prevention compared to either agent alone, according to the American Society of Anesthesiologists 1, 2

PONV is a common complication following surgery, particularly in high-risk patients, requiring effective prophylaxis, as noted by the World Journal of Emergency Surgery 1
Risk factors for PONV include female gender, history of PONV or motion sickness, non-smoking status, and use of volatile anesthetics or opioids, as identified by the World Journal of Emergency Surgery 1
A multimodal approach using antiemetics from different pharmacological classes is recommended for patients with multiple risk factors, as suggested by the American Society of Anesthesiologists and the World Journal of Emergency Surgery 1, 2

Ondansetron is effective in reducing postoperative vomiting and the need for rescue antiemetics, with a typical prophylactic dose of 4 mg IV administered before the end of surgery, according to the American Society of Anesthesiologists 2, 3
Dexamethasone significantly reduces PONV incidence in the first 24 hours and decreases the need for rescue antiemetics for up to 72 hours, with a recommended dose of 4-5 mg, as noted by the World Journal of Emergency Surgery and the American Society of Anesthesiologists 1, 4

For moderate to high-risk patients, a first-line combination of ondansetron 4 mg IV plus dexamethasone 4-5 mg IV administered before the end of surgery is recommended, as suggested by the World Journal of Emergency Surgery and the American Society of Anesthesiologists 1
For patients with ≥2 risk factors, consider adding a third antiemetic agent from a different class, as recommended by the American Society of Anesthesiologists and the World Journal of Emergency Surgery 1, 2

If PONV occurs despite prophylaxis, administer a rescue antiemetic from a different pharmacological class than those used for prophylaxis, as suggested by the World Journal of Emergency Surgery 1
Ondansetron is effective as rescue treatment for established PONV during recovery, according to the American Society of Anesthesiologists 2

Using only a single agent in high-risk patients is often insufficient, as noted by the World Journal of Emergency Surgery and the American Society of Anesthesiologists 1, 2
Underdosing dexamethasone (doses <4 mg may be less effective) should be avoided, as recommended by the American Society of Anesthesiologists and the World Journal of Emergency Surgery 4
The potential immunosuppressive effects of dexamethasone on long-term oncological outcomes remain unknown and should be considered in cancer surgery, as noted by the World Journal of Emergency Surgery and the American Society of Anesthesiologists 1, 4

The American Society of Anesthesiologists recommends against using Phenergan (promethazine) as a first-line agent for postoperative nausea and vomiting, instead supporting the use of 5-HT3 antagonists, dopamine antagonists, and corticosteroids as preferred agents 5, 6
The American Society of Anesthesiologists and the ERAS Society do not include promethazine in their evidence-based recommendations for PONV, citing a lack of Category A or B evidence 5, 6, 7, 8
Droperidol effectively reduces postoperative nausea, vomiting, and rescue antiemetic use compared to placebo, according to the American Society of Anesthesiologists 5, 6

The American Society of Anesthesiologists guidelines evaluated 5-HT3 antagonists, dopamine antagonists, anticholinergics, and corticosteroids, but promethazine was not among the agents with Category A or B evidence 5, 6