# The Effect of Thermal-Softened Endotracheal Tubes on Postoperative Sore Throat and Other Complications—A Systematic Review and Meta-Analysis

## TL;DR

This study finds that thermal-softened endotracheal tubes may reduce post-surgery sore throats and vocal cord damage but don't affect hoarseness or intubation time.

## Contribution

The novel contribution is a systematic review and meta-analysis showing thermal-softened ETTs reduce postoperative sore throat and vocal cord lesions.

## Key findings

- Thermal-softened ETTs reduced postoperative sore throat incidence by 40%.
- Vocal cord lesions were 48% less common with thermal-softened ETTs.
- No significant effect on hoarseness or intubation time was observed.

## Abstract

Background: Endotracheal tube (ETT) intubation during general anesthesia (GA) is commonly associated with postoperative sore throat. This study aimed to evaluate whether thermal-softened ETTs reduce the postoperative sore throat incidence in patients undergoing elective surgery under GA. Methods: We conducted a comprehensive search of the literature across PubMed, Cochrane Library, and EMBASE to identify randomized controlled trials (RCTs) evaluating the effect of thermal-softened ETTs on postoperative sore throat in patients undergoing elective surgeries under GA. The primary outcome was postoperative sore throat incidence, while secondary outcomes included hoarseness, vocal cord lesions, and time to intubation. Data were extracted independently by two authors, and the risk of bias was assessed using the Revised Cochrane risk of bias tool (version 2.0). A meta-analysis was then performed using the random-effects model, with the results expressed as risk ratios (RRs) and mean difference (MDs). Results: Eight studies, with a total of 970 participants, were included. Thermal-softened ETTs significantly reduced postoperative sore throat incidence (RR: 0.60, 95% CI: 0.44 to 0.82, p = 0.001). Subgroup analysis showed no difference for single-lumen tubes (RR: 0.76, 95% CI: 0.45 to 1.26, p = 0.28), but remained significant for double-lumen tubes (RR: 0.5, 95% CI: 0.39 to 0.65, p < 0.00001). No significant difference was found in hoarseness (RR: 0.86, 95% CI: 0.64 to 1.17, p = 0.34), but a lower incidence of vocal cord lesions (RR: 0.52, 95% CI: 0.40 to 0.68, p < 0.00001) was observed. No difference was found in the time to intubation (MD: −6.51, 95% CI: −20.04 to 7.02, p = 0.35). Conclusions: Thermal-softened ETTs may reduce the incidence of postoperative sore throat and vocal cord lesions but have no significant effect on hoarseness or intubation time.