Background

• Severe pain after tonsillectomy delays recovery and limits oral intake.
• The tonsils are innervated by both the maxillary and glossopharyngeal nerves, but their roles in pain perception remain unclear.
• Maxillary nerve block (MaxNB) is commonly used in dental surgery, but its effectiveness for tonsillectomy pain is unknown.
• This study evaluates the efficacy and safety of MaxNB for postoperative analgesia in tonsillectomy.

Methods

Study Design

• Ethics approval: Sapporo Medical University Hospital (322-294).
• Patients: 44 ASA I–III tonsillectomy patients, randomized 1:1 (Mujinwari).
• Exclusions: Allergy, coagulopathy, chronic opioid use, neuropathy, pregnancy, psychiatric disorders, failed extubation.

Blinding

• Patients, evaluators, block anesthesiologists, and surgeons were blinded.

Anesthesia & Postoperative Management

• General Anesthesia (GA): Propofol, remifentanil (BIS-guided), IV acetaminophen (15 mg/kg, max 1000 mg).
• Rescue Analgesia: IV fentanyl (25 µg = 2.5 mg MME) for pain after extubation.

Regional Block

• Intervention Group: Bilateral MaxNB (5 mL 0.375% levobupivacaine per side).
• Placebo Group: Saline injection.

Postoperative Analgesia

• IV acetaminophen (q6h).
• IV fentanyl PCA (20 µg bolus = 2 mg MME, no basal infusion).
• Rescue NSAIDs (flurbiprofen 50 mg).

Outcomes

• Primary Outcome: VAS at rest (0, 2, 4, 8, 24h).
• Secondary Outcomes:
  • VAS at swallowing, rescue analgesic use, intraoperative opioid consumption.
  • Cumulative MME/day, QoR-40 score.
  • Nausea, block-related complications, respiratory events (24h).

Analysis

• Primary Analysis: Two-way ANOVA.
• Secondary Analysis: t-test / Mann-Whitney U.
• Significance: p < 0.05.

Results

• One patient withdrew, leaving 20 patients in the block group and 23 in the placebo group.
• VAS scores at rest showed no significant difference at any time within 24 hours.
• Median [IQR] cumulative fentanyl consumption also did not differ significantly
  • Block: 50 [20–170] µg/day (5 [2–17] mg MME)
  • Placebo: 40 [0–140] µg/day (4 [0–14] mg MME)
  • p = 0.62
• All secondary outcomes were also not significantly different.

Discussion & Conclusion

• MaxNB did not reduce pain or opioid use after tonsillectomy.
• Despite regular acetaminophen, both groups had high pain levels, suggesting glossopharyngeal nerve dominance in tonsillar pain.

Limitations

• Block success was not confirmed due to the double-blind design.
• Injection site: Local anesthetic was administered above the lateral pterygoid plate, but direct delivery to the maxillary nerve is uncertain.
• Combination of maxillary and glossopharyngeal nerve blocks was not evaluated.

Conclusion

• MaxNB did not provide significant pain relief or reduce opioid use.