From the Guidelines
The most effective approach to prevent postoperative nausea and vomiting (PONV) after a cesarean section is a multimodal strategy that combines pharmacological and non-pharmacological interventions, including the use of antiemetic agents such as 5-HT3 antagonists (e.g., ondansetron, granisetron) and dopamine antagonists (e.g., metoclopramide, droperidol) 1. This approach is supported by a Cochrane review study that demonstrated the effectiveness of these agents in reducing intraoperative nausea and vomiting 1. A combination of dexamethasone 4-8 mg IV at the beginning of surgery and ondansetron 4 mg IV near the end of the procedure provides effective prophylaxis, and for high-risk patients, adding a third agent such as droperidol 0.625-1.25 mg IV or scopolamine transdermal patch applied the evening before or morning of surgery can be beneficial 1. Other interventions that can help reduce PONV risk include adequate hydration with IV fluids, minimizing the use of opioids by incorporating NSAIDs like ketorolac 30 mg IV or ibuprofen 600 mg orally, and using neuraxial morphine rather than systemic opioids when possible 1. Additionally, early ambulation and progressive oral intake starting with clear liquids can further decrease symptoms. The use of a multimodal approach is strongly recommended by the Enhanced Recovery After Surgery (ERAS) Society, with a moderate evidence level and strong recommendation grade 1. Key points to consider when implementing this approach include:
- The use of antiemetic agents such as 5-HT3 antagonists and dopamine antagonists
- The combination of dexamethasone and ondansetron for effective prophylaxis
- The addition of a third agent for high-risk patients
- Adequate hydration and minimization of opioid use
- Early ambulation and progressive oral intake. This approach targets different pathways involved in PONV, including serotonin, dopamine, and histamine receptors, while addressing contributing factors like dehydration and excessive opioid use, which can trigger the chemoreceptor trigger zone in the brain stem and lead to nausea and vomiting 1.
From the Research
Prevention of Postoperative Nausea and Vomiting (PONV) after Cesarean Section (C-section)
To prevent PONV after a C-section, several approaches can be considered based on the available evidence:
- Metoclopramide: Studies have shown that metoclopramide can be effective in preventing PONV after a C-section 2. A dose of 10 mg given before block placement or after delivery has been found to reduce the incidence of intraoperative and postoperative nausea and vomiting.
- Comparison with Other Antiemetics: Research comparing metoclopramide with other antiemetics like ondansetron and tropisetron suggests that while metoclopramide may not always be the most effective, it still offers significant benefits in preventing PONV 3.
- Multimodal Regimens: The use of a multimodal regimen that includes metoclopramide along with other drugs such as dexamethasone, ondansetron, and droperidol has been shown to provide superior prolonged antiemetic prophylaxis compared to propofol or placebo 4.
- Systemic Metoclopramide: A meta-analysis found that systemic metoclopramide (10 mg) is effective in preventing PONV in patients undergoing surgical procedures under general anesthesia, including those undergoing C-sections 5.
Key Findings
- Metoclopramide is effective in reducing the incidence of PONV after C-section 2, 5.
- The drug can be administered before block placement or after delivery to achieve its antiemetic effects 2.
- While metoclopramide may not always outperform other antiemetics, it remains a viable option for PONV prevention 3.
- Multimodal antiemetic regimens that include metoclopramide can offer enhanced protection against PONV 4.