A randomised controlled trial of 7.5‐mm and 7.0‐mm tracheal tubes vs. 6.5‐mm and 6.0‐mm tracheal tubes for men and women during laparoscopic surgery

Sore throat after tracheal intubation impairs postoperative recovery. We randomly allocated 172 ASA physical status 1-2 participants, scheduled for laparoscopic lower abdominal surgery, to tracheal intubation with larger tubes (n = 88) or smaller tubes (n = 84), with internal diameters 7.5-mm vs. 6.5-mm for men and 7.0-mm vs. 6.0-mm for women. Primary outcome was the rates of no, mild, moderate or severe sore throat 1 h after surgery, which were 60, 10, 17 and 1 with larger tracheal tubes and 79, 5, 0 and 0 with smaller tubes, p < 0.001. The equivalent rates 24 h after surgery were 64, 16, 8 and 0 vs. 74, 6, 3 and 1, p = 0.037. Intra-operative ventilatory variables were unaffected by tube diameter, including peak inspiratory pressure, plateau pressure and end-tidal carbon dioxide partial pressure. In summary, smaller tracheal tubes benefitted patients having laparoscopic operations.