Laryngeal mask beat breathing tube on airway events in a children's trial

Which device an anaesthetist uses to manage a child's airway during tonsil and adenoid surgery may shape how often that child has a breathing problem around the operation. In a randomised trial published in The BMJ, children ventilated with a laryngeal mask airway had far fewer perioperative respiratory complications than those given a conventional breathing tube [s1]. It is a single trial, done at specialist centres, but the gap it reports is large and consistent.

The question

Adenotonsillectomy — removing the tonsils and adenoids — is one of the most common operations in young children. Because it is performed in the mouth and throat, the airway is both the surgical field and the thing the anaesthetist must keep open, and respiratory problems such as coughing, spasm of the voice box or drops in oxygen are the usual complications. The standard device is an endotracheal tube (ETT), which passes between the vocal cords; the alternative is a laryngeal mask airway (LMA), which sits above them and is less invasive. The trial asked whether the choice between them changes how often those breathing problems happen.

What the trial did

Researchers ran a multicentre, randomised, parallel-group trial at four tertiary hospitals in China during 2023 and 2024 [s1]. They enrolled 400 children aged two to under seven who were scheduled for adenotonsillectomy under general anaesthesia, and randomly assigned them one-to-one to ventilation with a laryngeal mask airway (200 children) or an endotracheal tube (200 children) [s1]. The trial is registered as ChiCTR2300071399 [s2].

The primary outcome was the proportion of children who had any perioperative respiratory adverse event — defined as laryngospasm, bronchospasm, oxygen desaturation, airway obstruction, severe cough or stridor — analysed by intention to treat [s1]. The children had a mean age of 4.7 years, and 155 (38.7%) were girls; they were enrolled between 24 May 2023 and 4 April 2024, with the last follow-up on 4 May 2024 [s1]. In three children, the laryngeal mask had to be converted to a tube [s1].

What it found

Overall, 22.5% of children in the laryngeal-mask group (45 of 200) had a respiratory adverse event, compared with 57.5% in the tube group (115 of 200) — an absolute difference of 35.0 percentage points (95% confidence interval −43.5 to −25.7) [s1]. The advantage held in both phases of care: during the operation, 9.0% versus 17.5%, and afterwards, 16.5% versus 49.5% [s1].

The individual complications told the same story. Laryngospasm occurred in none of the laryngeal-mask group versus 3.0% of the tube group; oxygen desaturation in 15.0% versus 28.0%; airway obstruction in 3.5% versus 12.5%; and severe cough in 10.5% versus 42.0% [s1]. Neither group had any serious adverse events [s1].

How to read it

The effect is large, but several features set its boundaries. This was a single trial at four tertiary hospitals, and the authors are explicit that the laryngeal mask was placed "by experienced anaesthesiologists" [s1] — airway devices are operator-dependent, and the result may not transfer directly to centres with less experience in the technique for this operation. The trial was also not blinded in the way a drug trial can be: the anaesthetists knew which device they were using, and several of the outcomes, such as severe cough, involve some judgement, which can bias open assessments.

The trial measured events around the time of surgery, a window of hours to a day, not longer-term recovery or any difference in the success of the operation itself. And it was conducted in one country in a specific age band — two to under seven — so it speaks to young children at specialist centres rather than to every patient or setting. What it does not address is how the two devices compare on surgical access or on rarer but serious events that a 400-child trial is too small to count reliably.

What it means

Within those limits, the message is straightforward: in experienced hands, a laryngeal mask was associated with substantially fewer breathing complications than a tube in young children having their tonsils and adenoids removed [s1]. That is the kind of finding that can inform how anaesthetists weigh the two options, and it strengthens the case for the less invasive device in this specific operation — pending confirmation in other settings and by teams with varying levels of experience.

This article describes a clinical trial comparing two standard anaesthetic techniques and is not medical advice. Decisions about how a child's airway is managed during surgery are for the anaesthetic and surgical team.