Local anaesthetic for post-tonsillectomy pain: a systematic review and meta-analysis

Background: Tonsillectomy is one of the most commonly performed procedures in otolaryngology. Pain is a significant aspect of post-operative patient morbidity. The use of local anaesthetic, by infiltration or topical application, has been advocated as a way of reducing post-operative pain. Objectives: To review the current evidence for the use of local anaesthetic as a means of reducing post-tonsillectomy pain and reducing supplemental analgesic requirements. Type of review: A systematic review of the literature pertaining to the use of local anaesthetic agents for post-tonsillectomy pain and meta-analysis of randomised control trials assessing pain scores. Search strategy: Systematic literature searches of MEDLINE (1952-2008), EMBASE (1974-2008) and the Cochrane Central Register of Controlled Trials. Evaluation method: Review of all randomised controlled trials by two authors and grading of articles for quality. Results: Thirteen studies were included. Overall, local anaesthetic, applied topically or infiltrated, significantly reduces pain scores compared with controls at 4-6 h, -0.66 (95% CI: -0.82, -0.50); 20-24 h, -0.34 (95% CI: -0.51, -0.18) and on day 5, -0.97 (95% CI: -1.30, -0.63) (standardised mean differences). These changes approximate to a reduction in pain of between 7 and 19 mm on a 0-100 mm visual analogue scale. Most studies did not report a difference in supplemental analgesia or in adverse events. Conclusion: Local anaesthetic does seem to provide a modest reduction in post-tonsillectomy pain. Topical local anaesthetic on swabs appears to provide a similar level of analgesia to that of infiltration without the potential adverse effects and should be the method of choice for providing additional post-operative analgesia.