Opioid-Free Pediatric Tonsillectomy With Intraoperative Maxillary Nerve Block Via Suprazygomatic Injection (OPTIMaS): A Randomized Controlled Triple-Blinded Trial

Tonsillectomies are among the most common surgical procedures performed in pediatric populations, with more than 14,000 procedures performed annually in Ontario. Despite being a routine procedure, postoperative pain is a prevalent challenge following tonsillectomies, with significant pain lasting 7 to 10 days and peaking within the first 3 days following surgery. Effective pain management is critical not only to enhance patient comfort, but to ensure functional recovery, decrease the risk of post-surgical complications, and reduce the risk of hospital readmissions. More than 80% of tonsillectomies are performed to treat sleep-disordered breathing (SDB), an array of conditions including obstructive sleep apnea (OSA) that are characterized by abnormal respiratory patterns during sleep. Patients with these conditions often undergo an upregulation of central μ-opioid receptors due to chronic apnea, decreasing their response to hypercarbia and increasing opioid sensitivity. When opioids are administered for pain management, these patients are at a greater risk of hypoventilation and hypoxemia. Many nonopioid analgesics such as acetaminophen, non-steroidal anti-inflammatory drugs, and some corticosteroids provide varying degrees of efficacy in pain relief, acting more effectively in combination with other medications to maximize pain management while mitigating adverse effects.

The suprazygomatic maxillary nerve block (SZMN block) has become a promising alternative to systemic opioids for the management of post-tonsillectomy pain. The SZMN block targets the palatine branch of the maxillary nerve in the pterygopalatine fossa, providing partial analgesia to the adenoids while avoiding the glossopharyngeal nerve, thereby preserving airway reflexes and reducing the risk of respiratory compromise. Although the SZMN block has been successful in adult tonsillectomies and pediatric cleft palate repairs, its success in pediatric tonsillectomies remains under investigation. Reported complications are rare and easily managed, including perioperative bleeding and postoperative hematoma formation at the injection site. A recent randomized clinical trial by Lin et al. demonstrated the efficacy of the SZMN block in reducing opioid use and alleviating postoperative pain in pediatric patients during the immediate postoperative period, particularly the post-anesthesia care unit (PACU) stay and the first three days following surgery. However, its efficacy in pediatric tonsillectomy patients has not been evaluated over the initial 14-day postoperative period, during which patients commonly experience sustained, significant pain. The current investigation aims to evaluate the efficacy and safety of the SZMN block in pediatric tonsillectomy and adenotonsillectomy patients, through its role in providing pain management over 14 days following surgery.

Prior to enrollment in the study, informed consent will be sought from the parents/guardians of these children and assent will be obtained where appropriate. Upon enrollment in the study, patients will be randomized by a computer generated sequence into one of two study groups. The investigators, participants, and outcome assessors will be blinded to participant group assignment at the time of randomization and throughout treatment and assessment.

Group 1: Participants will receive 15 mg/kg of Tylenol and 6 mg/kg of celecoxib (a nonsteroidal anti-inflammatory (NSAID drug) up to a maximum dose of 200 mg prior to the start of general anesthesia which will consist of gas or intravenous induction (2 mcg/kg fentanyl, 0.5 mg/kg dexamethasone). The SZMN block will be performed using 0.2 ml/kg bilaterally of 0.25% bupivacaine (MARCAINE) (cumulative dose 0.4 ml/kg) (local anesthetic), up to a maximum dose of 5 mL per side. The surgery (tonsillectomy or adenotonsillectomy) will then proceed according to standard of care practices.

Group 2: Participants will receive 15 mg/kg of Tylenol and 6 mg/kg of celecoxib (a nonsteroidal anti-inflammatory (NSAID drug) up to a maximum dose of 200 mg prior to the start of general anesthesia. which will consist of gas or intravenous induction (2 mcg/kg fentanyl, 0.5 mg/kg dexamethasone). The SZMN block will be performed using 0.2 ml/kg of saline (placebo) up to a maximum dose of 5 mL per side. The surgery (tonsillectomy or adenotonsillectomy) will then proceed according to standard of care practices.