Comparing Intramuscular Fentanyl and Ketorolac With Nerve of Arnold (NOA) Block for Bilateral Myringotomy

Background: Bilateral myringotomy with tympanostomy tube (BMT) placement is one of the most common pediatric surgical procedures. Despite its brief duration, many children experience significant postoperative pain. Current standard care typically involves intramuscular (IM) administration of an opioid (fentanyl) combined with a non-steroidal anti-inflammatory drug (ketorolac). While this multimodal approach provides adequate pain control for approximately 75% of children, it is associated with opioid-related side effects including respiratory depression, nausea, vomiting, and sedation. Additionally, nearly one-quarter of children still experience moderate-to-severe pain despite this regimen.

The Nerve of Arnold block is a regional anesthesia technique that involves injection of local anesthetic near the auricular branch of the vagus nerve, which provides sensory innervation to the external auditory canal and tympanic membrane. This technique offers the potential for targeted, opioid-sparing analgesia with extended duration and minimal systemic side effects. However, high-quality evidence comparing this regional technique to standard systemic analgesia in pediatric patients is lacking.

Study Objective: This study aims to determine whether the Nerve of Arnold block is non-inferior to the standard combination of IM fentanyl and IM ketorolac in controlling postoperative pain in children undergoing BMT placement.

Study Design: This is a prospective, randomized, double-blind, non-inferiority trial. Three hundred children aged 6 months to 6 years scheduled for bilateral myringotomy with tympanostomy tube placement will be randomized 1:1 to receive either: (1) Standard care: IM fentanyl (1-2 mcg/kg) plus IM ketorolac (0.5 mg/kg) with sham Nerve of Arnold block, or (2) Intervention: Bilateral Nerve of Arnold block with bupivacaine 0.25% plus sham IM injections. Both patients and outcome assessors will be blinded to treatment assignments.

Primary Outcome: The proportion of patients experiencing moderate-to-severe pain (Face, Legs, Activity, Cry, Consolability \[FLACC\] scale score ≥4) in the Post-Anesthesia Care Unit (PACU). Non-inferiority will be declared if the upper bound of the 95% confidence interval for the difference in proportions is less than 10 percentage points.

Secondary Outcomes: Secondary outcomes include mean and maximum FLACC scores, rescue analgesic requirements, respiratory depression, postoperative nausea and vomiting, PACU length of stay, parent satisfaction, and pain at 24 hours postoperatively.

Clinical Significance: If the Nerve of Arnold block is shown to be non-inferior to standard care, it could provide a valuable opioid-sparing alternative for postoperative pain management in pediatric ear surgery, potentially reducing opioid-related adverse events while maintaining effective analgesia. This would be particularly beneficial for patients with contraindications to opioids or NSAIDs and aligns with national efforts to reduce opioid exposure in pediatric populations.