Efficacy of Local Bupivacaine Injection for Post-Operative Pain in Endoscopic Sinus Surgery

Clinical Question

Does general anesthesia in combination with local bupivacaine injection at the sphenopalatine ganglion (SPG) and anterior ethmoid nerve reduce post-operative pain after endoscopic sinus surgery (ESS)?

Bottom Line

Post-operative injection of 0.5% bupivacaine effectively reduces early post-operative pain (up to 6 hours), delays the need for rescue analgesia, and increases the likelihood of avoiding additional analgesics after ESS, with no significant safety concerns.

Background: Post-operative pain following ESS is typically mild to moderate but can impair recovery and prolong hospitalization. There is a need for effective post-operative pain management that reduces the need for analgesics with potential adverse effects. Regional nerve blocks targeting the SPG and anterior ethmoid nerve have emerged as promising approaches for improving post-operative pain management.

Study Design: Prospective, double-blind randomized controlled trial of 80 adults (18-75 years old) with chronic rhinosinusitis undergoing bilateral ESS. Patients were randomized to receive either 0.5% bupivacaine or normal saline injected at the SPG and anterior ethmoid nerve following ESS. Pain was assessed using visual analog scale (VAS) scores at multiple time points up to 24 hours.

Setting: Single tertiary academic center in Thailand

Synopsis: Eighty patients were randomized equally between bupivacaine and normal saline. Post-operative VAS pain scores were significantly lower in the bupivacaine group at one, two, four, and six hours, with adjusted mean differences ranging from 1.25 to 2.29 (all p ≤ 0.004). Pain scores at later time points (eight to 24 hours) were not significantly different. Overall, 24-hour pain scores remained significantly lower in the treatment group (p < 0.001), with a moderate effect size (Cohen’s d = 0.45). Analgesic requirements showed meaningful differences. While acetaminophen and morphine use did not differ significantly, patients receiving bupivacaine were more likely to require no post-operative analgesia (adjusted OR 2.67, p = 0.041). Additionally, time to first rescue analgesia was significantly prolonged (adjusted hazard ratio 0.51, p = 0.049), indicating delayed need for additional pain control.

Only one post-operative complication (bleeding) was reported, with no adverse effects attributed to bupivacaine. Limitations include single-center design, lack of active comparator (e.g., lidocaine), and limited control of intraoperative analgesic regimens. Nonetheless, the findings support targeted nerve blockade as an effective adjunct for early post-operative pain control after ESS.

Citation: Leewannapasai W, et al. Efficacy of local bupivacaine injection of postoperative pain in endoscopic sinus surgery. Int Forum Allergy Rhinol. 2026;16:231-238. doi:10.1002/alr.70059.

Comment: While local anesthetic is often used during rhinologic procedures for intra-operative hemostasis afforded by the addition of epinephrine, this study evaluated the effect on post-operative pain by using an injection of local anesthetic after completion of the surgery. In a double-blinded trial, patients were randomized to receive bupivacaine versus saline injections of the sphenopalatine ganglion and anterior ethmoid nerve. Those who received the local anesthetic experienced a significant reduction in post-operative pain and a reduced need for analgesic medications, with a statistically significant reduction in pain up to six hours after surgery. This intervention could improve the immediate post-operative patient experience and reduce the need for opioids or ketorolac in this period, both of which have potential downsides.—Ashoke Khanwalkar, MD