Guideline Recommendations for Anesthesia Management of High‑Risk PONV Patients Undergoing Tonsillectomy

Antiemetic Prophylaxis

5‑HT₃ antagonist – Administer ondansetron 4–8 mg IV (or granisetron 1 mg IV) at the end of surgery to reduce postoperative nausea and vomiting (PONV). 1
Dexamethasone 8 mg IV – Give at induction; provides both anti‑emetic and analgesic benefits in the peri‑operative period. 2
Dopamine antagonist – Use droperidol 0.625–1.25 mg IV (or haloperidol 0.5–1 mg IV) as an additional anti‑emetic class. 1
Gabapentinoid adjunct – Administer gabapentin 600 mg PO (or pregabalin 150 mg PO) pre‑operatively for supplemental analgesia and a possible anti‑emetic effect. 4

Propofol‑based total intravenous anesthesia (TIVA) – Maintaining TIVA throughout the case eliminates volatile‑agent–related PONV risk. 2
Opioid minimization intraoperatively – Rely on multimodal analgesia (paracetamol, NSAIDs, dexamethasone, gabapentinoids) to limit intra‑operative opioid use, which further reduces PONV incidence. 2
Maintain normothermia and adequate oxygenation – Core temperature control and optimal oxygen delivery are associated with lower PONV rates. 1
Ensure smooth emergence – A calm emergence reduces agitation‑related nausea. 1

Paracetamol 1000 mg IV/PO – Core component of peri‑operative analgesia. 2
NSAIDs – Ibuprofen 400–600 mg PO or ketorolac 30 mg IV can be used safely; they do not increase postoperative bleeding risk in tonsillectomy. [2][6]
Dexmedetomidine infusion – Consider intra‑operative infusion when opioid avoidance is critical. 4

Rescue‑only postoperative opioids – Reserve opioids for breakthrough pain after surgery; avoid routine intra‑operative dosing. [2][5]

Standard PACU monitoring – Observe for nausea, vomiting, pain, and respiratory complications during recovery. 1

Metoclopramide 10 mg IV – Effective for vomiting within the first 24 h when prophylaxis fails. 1
Additional 5‑HT₃ antagonist dose – Give if a recent dose has not been administered. 1
Promethazine 12.5–25 mg IV – Useful rescue anti‑emetic, noting potential sedation. 1

Paracetamol 1000 mg every 6 h – Continue as part of multimodal pain control. 2
NSAIDs (ibuprofen 400–600 mg every 6–8 h) – Maintain analgesia without increasing bleeding risk. 2
Honey consumption – Recommended as an adjunct analgesic with no reported side effects. [3][6]

Ketamine – Not recommended for adult tonsillectomy; evidence supports its use only in pediatric patients. 4