GLP-1 use increases risk of aspiration under anaesthesia, study finds

As the use of GLP-1 medications increase – some prescribed and some not prescribed – Perth-based anaesthetist Dr Peter Baumgartner said the findings served as a timely reminder to ask patients if they are using these drugs.

The study, published in the journal Anaesthesia, followed 47,039 patients across the UK. Around one in 36 were using GLP-1 RAs.

Research found differences in how these medicines were managed before surgery and in how anaesthesia and airway care were provided.

Regurgitation or pulmonary aspiration happened in about 1 in 71 patients taking GLP-1 medicines, compared with about 1 in 802 patients who were not taking them.

These events most often happened as patients were waking up from anaesthesia, the study found.

While conducted in the UK, it has impacts for care in Australia. In July, a study found half a million Australians were now using GLP-1s.

Dr Baumgartner said the findings may not be linked only to medication and that diabetes and obesity also increase regurgitation risk.

He told Medical Forum it was important to note other mitigating factors contributing to regurgitation and pulmonary aspiration during surgery.

“Only a third of the GLP-1 group had some specific medication and fasting regime for regurgitation risk reduction. All anaesthetic candidates have some sort of fasting regime that tries to reduce regurgitation risk," he said.

“We don’t have comparative data in Australia but my own impression is that about half of patients are following my preference to withhold last dose and have a liquid diet for the day before surgery.”

Dr Baumgartner added that as GLP-1s become more widely used, anaesthetists were relying on GPs and surgeons to also provide advice to patients on using the medications safely before surgery.

“As a strategy to reduce risk, stopping the last weekly dose and using a liquid diet for 24 hours is easier to institute and won’t result in severe disruption of a patient’s medical management.

“Implementation by the GP, anaesthetist and surgical team is the best chance to reduce the incidence of a full stomach in patients taking GLP1 who are having anaesthesia.”

It comes as the Australian and New Zealand College of Anaesthetists urged patients using GLP-1s and peptides not to assume they are irrelevant to anaesthesia.

ANZCA President Dr Tanya Selak said: “These medications can slow the emptying of the stomach which may still contain food or other material even when you have followed the usual fasting instructions.

“We know of some rare cases where the consequences of stomach contents entering the lungs during surgery can be extremely serious and life-threatening for patients.”

ANZCA's patient information now generally allows small amounts of clear liquids until patients are called to theatre, while solid food and non-clear fluids should stop six hours before elective surgery.

ANZCA also provides clinical practice recommendations for patients using GLP-1s, available here.