Postoperative Vomiting After Appendectomy
Yes, vomiting after appendectomy is a common and expected complication, occurring in up to 80% of high-risk patients, though it should be actively prevented and treated rather than simply accepted as "normal." 1
Understanding PONV Risk After Appendectomy
Postoperative nausea and vomiting (PONV) represents one of the most frequent complications following appendectomy, particularly affecting patients with multiple risk factors. 2
Key risk factors include:
- Female sex
- Non-smoking status
- History of motion sickness or previous PONV
- Use of volatile anesthetics and postoperative opioids 1, 3
Evidence-Based Prevention Strategy
All appendectomy patients should receive prophylactic antiemetic therapy based on their risk profile, not wait until vomiting occurs. 1
For Patients with 1-2 Risk Factors:
- Administer ondansetron 4 mg IV plus dexamethasone 4-5 mg IV before the end of surgery 3, 4
- This combination provides superior prevention compared to either agent alone 3
For High-Risk Patients (≥2-3 Risk Factors):
- Use triple prophylaxis: ondansetron 4 mg + dexamethasone 4-5 mg + a third agent from a different class 1, 3
- Consider adding scopolamine patches or metoclopramide 20-25 mg 1, 5
- For patients failing standard dual prophylaxis, olanzapine 10 mg can reduce PONV from 63% to 26% 6
Clinical Evidence Specific to Appendectomy
A 2024 randomized controlled trial demonstrated that ondansetron significantly reduced postoperative vomiting after acute appendicitis surgery at 2 hours (5% vs. 25%) and 6 hours (7.5% vs. 27.5%) compared to placebo. 4 This confirms that PONV is common but highly preventable with appropriate prophylaxis.
Treatment When Vomiting Occurs Despite Prophylaxis
If vomiting develops despite adequate prophylaxis, administer rescue antiemetics from a different pharmacological class than those used for prevention. 1, 3
- If ondansetron was used prophylactically, switch to a dopamine antagonist (metoclopramide) or anticholinergic
- Avoid using the same drug class for rescue therapy 1
Critical Pitfalls to Avoid
Common mistakes that worsen outcomes:
- Using only single-agent prophylaxis in patients with multiple risk factors—this is insufficient 3, 6
- Underdosing dexamethasone (doses <4 mg are less effective) 3
- Waiting for vomiting to occur before treating rather than providing prophylaxis 1, 2
- Liberal use of opioids without multimodal analgesia, which increases PONV risk 1
When to Worry: Red Flags
While some vomiting may occur, persistent vomiting beyond 24 hours or accompanied by tachycardia, fever, or progressive abdominal pain suggests a complication such as:
- Anastomotic leak or abscess (though rare in simple appendectomy) 1
- Stump appendicitis (in patients with prior appendectomy) 7, 8
- Bowel obstruction 1
Tachycardia is the most alarming early postoperative sign and should prompt immediate evaluation. 1
Practical Implementation
The multimodal approach should include:
- Risk assessment using the Apfel score preoperatively 1, 2
- Prophylactic antiemetics administered before emergence from anesthesia 3
- Total intravenous anesthesia (TIVA) rather than volatile gases when possible 1
- Multimodal analgesia with acetaminophen and NSAIDs to reduce opioid requirements 1
- Early oral intake within 2-4 hours post-surgery to facilitate recovery 1