VOLUME 35, ISSUE 2

“♪♫O-o-o-Ozempic♪♫! You know…”

The ads – and the jingle that sticks in the brain like gum on a shoe – for the glucagon-like peptide-1 (GLP-1) agonist semaglutide (Ozempic) seem to be everywhere, as well as for its GLP-1 brethren, Wegovy (semaglutide), Trulicity (dulaglutide) and Victoza (liraglutide). While initially approved in the treatment of type 2 diabetes, they recently became the newest medications for weight loss (though Wegovy is the only one officially approved by the Food and Drug Administration).¹ This has resulted in a surge in patients on GLP-1 agonists, to the point that pharmacies struggle to keep the drugs in stock – especially after several celebrities have touted their success with the medications – and traditional weight loss businesses, like Jenny Craig – are closing their doors.²

Yet what is helpful for weight loss can also be a complication waiting to happen. For example, during a routine endoscopic gastroduodenoscopy (EGD) on a patient for bariatric surgical clearance – and despite more than adequate NPO time – the patient’s stomach looked like they had just walked into the building from eating at a buffet. The bariatric surgeon, who regularly performed such EGDs, remarked that this finding had become increasingly common. More of his patients were turning to short term usage of GLP-1 agonists in order to shed the last few pounds necessary to meet pre-surgical weight loss targets.

Within the pancreas, GLP-1 agonists stimulate insulin production from beta cells and reduce glucagon secretion from alpha cells. This results in lower glucose levels with minimal risk of hypoglycemia and also inhibits gastric emptying, resulting in weight loss through a persistent sense of satiety and thus overall decreased food intake.^3,4

However, it’s not all benefits, as two recent publications highlight the potential dangers. In a report of two patients with diabetes who underwent extensive testing for gastroparesis symptoms, no evidence of gastrointestinal obstruction was found yet gastric emptying tests demonstrated long delays. Careful histories revealed both had recently been started on a GLP-1 agonist. Once the medication was discontinued, their symptoms resolved and gastric emptying returned to normal.⁵ Similarly, a study in women with polycystic ovary syndrome found that patients started on GLP-1 agonists still had 30% of their last meal present four hours post-prandial, compared to zero in a placebo group. This effect resolved itself after 20 weeks on the medication and there was no difference at that point between study and placebo groups.⁶

The greatest concern is for patients on these medications to be at increased risk for aspiration due to an unrecognized medication-induced gastroparesis. In fact, a case report of a patient with delayed gastric emptying due to a GLP-1 medication with resulting intraoperative pulmonary aspiration was recently published by Klein, et. al.⁷

This has left many anesthesiologists grappling with how to provide safe care to patients on these medications. Do these patients need longer NPO times? Do all patients on GLP-1 agonists need a rapid sequence intubation? Should the medication be discontinued prior to anesthesia? Or perhaps the right course of action is some combination of these? There isn’t widely accepted guidance on the matter. Furthermore, there aren’t any published studies looking at NPO times to ensure gastric emptying for surgery or if the effect truly reverts to normal after being on the medication for lengthy times. It seems like the conversation on how to treat these patients is just beginning.

Gastric ultrasound may play an important role in the evaluation of these patients in the future to determine if they have delayed gastric emptying. As we all become more facile with point of care ultrasound, these gastric ultrasound evaluations may prove to be more helpful in risk stratifying patients on GLP-1 medications to determine if a patient is at increased risk for aspiration of gastric contents.

As more information is learned about this class of drugs, we expect further guidelines to be developed to guide best practices. Until such a time, it is important for all anesthesiologists to be aware of this side effect of this increasingly popular class of medication.

Addendum: Just prior to TSA Newsletter publication, the ASA published a statement regarding the use of these medications, recommending holding the scheduled dose prior to surgery. https://www.asahq.org/about-asa/newsroom/news-releases/2023/06/american-society-of-anesthesiologists-consensus-based-guidance-on-preoperative#table1

1. FDA Approves New Drug Treatment for Chronic Weight Management, First Since 2014. (2021, June 4). https://www.fda.gov/news-events/press-announcements/fda-approves-new-drug-treatment-chronic-weight-management-first-2014.
2. Rosen, NS. (2023, Jan 19). With growing popularity of new weight loss drugs, doctors emphasize potential risks. https://abcnews.go.com/Health/growing-popularity-new-weight-loss-drugs-doctors-emphasize/story?id=96424302.
3. Dahl K, Brooks A, Almazedi F, Hoff ST, Boschini C, Baekdal TA. Oral semaglutide improves postprandial glucose and lipid metabolism, anddelays gastric emptying, in subjects with type 2 diabetes. Diabetes Obes Metab. 2021 Jul;23(7):1594-1603. doi: 10.1111/dom.14373. Epub2021 Mar 29. PMID: 33710717; PMCID: PMC8251575.
4. Hulst AH, Polderman JAW, Siegelaar SE, van Raalte DH, DeVries JH, Preckel B, Hermanides J. Preoperative considerations of newlong-acting glucagon-like peptide-1 receptor agonists in diabetes mellitus. Br J Anaesth. 2021 Mar;126(3):567-571. doi: 10.1016/j.bja.2020.10.023. Epub 2020 Dec 17. PMID: 33341227.
5. Kalas MA, Galura GM, McCallum RW. Medication-Induced Gastroparesis: A Case Report. J Investig Med High Impact Case Rep. 2021 Jan-Dec;9:23247096211051919. doi: 10.1177/23247096211051919. PMID: 34663102; PMCID: PMC8529310.
6. Jensterle M, Ferjan S, Ležaič L, Sočan A, Goričar K, Zaletel K, Janez A. Semaglutide delays 4-hour gastric emptying in women withpolycystic ovary syndrome and obesity. Diabetes Obes Metab. 2023 Apr;25(4):975-984. doi: 10.1111/dom.14944. Epub 2023 Jan 3. PMID:36511825.
7. Klein, S.R., Hobai, I.A. Semaglutide, delayed gastric emptying, and intraoperative pulmonary aspiration: a case report. Can J Anesth/J CanAnesth (2023). https://doi.org/10.1007/s12630-023-02440-3.