Endotracheal tube size and sore throat following surgery: a randomized-controlled study

Sore throat following endotracheal intubation is a common problem following surgery and one of the factors that affects the quality of recovery. This study was carried out with the primary aim of assessing whether the size of the endotracheal tube (ETT) affects the risk of sore throat in women following anaesthesia.

One hundred healthy adult women undergoing elective surgery were randomly allocated to oral intubation with either ETT size 6.0 or 7.0. Anaesthesia was based on either inhalation or total intravenous anaesthesia according to standardized routines. Pre- and post-operatively, sore throat and discomfort were assessed on a four-graded scale and for hoarseness on a binary scale (yes or no). Post-operatively, the assessments were performed after 1-2 and 24 h, and if there was discomfort at 24 h, a follow-up call was made at 72 and 96 h.

After 1-2 h post-operatively, there were a higher proportion of patients with sore throat in ETT 7.0 vs. ETT 6.0 (51.1% vs. 27.1%), P=0.006. This difference between the groups was also evident, P=0.002, when comparing changes between the pre- and the post-operative values. The severity of discomfort from sore throat was also higher in ETT 7.0 (38.8%) compared with ETT 6.0 (18.8%), P=0.02. No differences were found in the incidence of hoarseness between the groups. The remaining symptoms lasted up to 96 h post-operatively in 11%, irrespective of the tube size.

Use of a smaller-sized ETT can alleviate sore throat and discomfort in women at the post-anaesthesia care unit.