Effects of anesthesia with nitrous oxide on tympanoplasty outcomes: a randomized controlled trial

General anaesthetic vs local anaesthetic myringoplasties: a systematic review and meta-analysis

AIMS

To assess all available data and determine the success rates and tolerability of local anaesthetic myringoplasty in comparison with those undertaken under general anaesthetic myringoplasty.

MATERIALS AND METHODS

The study was designed following a PRISMA-P protocol and registered with the PROSPERO database. MEDLINE, Cochrane Library (CDSR/Central), EMBASE and CINHAL-were directly searched for studies, which met the inclusion criteria.

OBJECTIVES

Primary objective was to compare perforation closure rates between patients undergoing myringoplasty under local anaesthetic and those under general anaesthetic from all available published data. Secondary outcomes include complications, such as 'any minor complications', infection rates in the first 6 month post-op, facial nerve weakness, dysgeusia and patient satisfaction.

RESULTS

27 studies were included in the final analysis and found that myringoplasty had an overall perforation closure rate of 89%. The pooled proportion of closures after myringoplasty under local anesthesia was 87% and for myringoplasties under general anesthesia was 91%. Analysis of myringoplasty under local anaesthesia focusing on 'in-office' performed procedures only, found a closure rate of 88%.

CONCLUSIONS

There is no significant difference in the success rate of myringoplasty surgery when performed under local or general anaesthetic as measured by perforation closure rates. However, there are other factors, which can drive choosing local anaesthetic surgery, such as minimising anaesthetic risks, reducing costs and reducing environmental impact.

The Effect of Nitrous Oxide on the Outcomes of Underlay Tympanoplasty: A Prospective Study

The main aims of tympanoplasty are eradication of chronic middle ear disease, repair of the tympanic membrane, and restoration of hearing. Nitrous oxide (N₂O) is not a commonly preferred anesthetic agent for tympanoplasty because this agent may increase middle ear pressure and displace the graft. In this study, we researched the surgical outcomes of the underlay tympanoplasty performed with N₂O anesthesia. Patients who underwent tympanoplasty were included in this prospective study. A type 1 tympanoplasty was performed in all patients using the underlay technique. Patients were randomized to groups that did and did not receive N₂O. Preoperative and postoperative hearing thresholds were evaluated, postoperative pain scores were recorded, and the differences between the groups were statistically evaluated. There were 44 patients who received N₂O and 44 who did not. The graft success rate was 93.2% in the N₂O-receiving group and 84.1% in the nonreceiving group (P > .05). Hearing levels improved significantly after surgery in each group (P < .05), but the difference between the groups was not significant (P > .05). The postoperative pain score was 3.72 ± 1.3 in the N₂O-receiving group and 4.45 ± 2.3 in the nonreceiving group (P > .05). Nitrous oxide is a cheap, safe, and readily available anesthetic agent that provides acceptable success rates in patients undergoing tympanoplasty.