Effects of the Local Injection of Bupivacaine and Lidocaine-Epinephrine Mixture on Post-Tonsillectomy Pain: A Controlled Clinical Trial

Introduction: Pain is the most common post-tonsillectomy complaint in children, whose insufficient relief can result in a number of complications. The present study aimed to determine and compare the effects of the local injection of bupivacaine and lidocaine-epinephrine mixture on post-tonsillectomy pain. Methodology: In this double-blind randomized clinical trial, 87 candidate children for tonsillectomy aged 4-10 years were selected through non-probability convenience sampling. The subjects were randomly assigned to 3 groups. All patients in the three groups underwent identical general anesthesia and cold knife dissection procedures. Five minutes before incision, children in the intervention groups received 2 mL of bupivacaine 0.125% and 2 mL of a mixture of lidocaine 1% and epinephrine (1:200,000), respectively, through tonsillar and peritonsillar local injection. Pain intensity was assessed 2, 4, 6, and 8 hours after surgery using the Wong-Baker Faces Pain Rating Scale. Data were analyzed in SPSS 21 using descriptive and inferential statistics at a 95% confidence interval and 0.05 significance level. Findings: The postoperative pain intensity ranged from 4 to 8 in the bupivacaine-receiving group, from 5 to 8 in the lidocaine-epinephrine mixture-receiving group, and from 6 to 10 in the control group. A statistically significant difference was observed in the median pain intensity among the three groups of children participating in the study (p=0.001). Although the pain intensity in the bupivacaine-receiving children was lower than lidocaine-epinephrine mixture-receiving children 2, 4, 6, and 8 hours after surgery, the difference was only statistically significant 2 and 4 hours postoperatively (p=0.001) and no statistically significant difference was observed in other times (p>0.05). There was a significant difference in the pain intensity between the two intervention groups and the control group at all times (2, 4, 6, and 8 hours after surgery) (p=0.001). Conclusion: Although local injection of bupivacaine and lidocaine-epinephrine mixture reduced post-tonsillectomy pain in children, there was no difference in their effect on pain reduction except 2 and 4 hours postoperatively.