Episode #160 Breaking Perioperative News: GLP-1 Receptor Agonist Alert
July 25, 2023Welcome to the next installment of the Anesthesia Patient Safety podcast hosted by Alli Bechtel. This podcast will be an exciting journey towards improved anesthesia patient safety.
We are taking a break from the June 2023 APSF Newsletter to bring you this special article between issues. Our featured article today is “Are Serious Anesthesia Risks of Semaglutide and Other GLP-1 Agonists Under-Recognized? Case Reports of Retained Solid Gastric Contents in Patients Undergoing Anesthesia” by William Beam and Lindsay Guevara. This article was published on June 8, 2023.
Thank you to William Brian Beam for contributing audio clips to the show today.
Primary mechanism of action for GLP-1 receptor agonists:
- Likely due to activation of vagal afferent nerves that innervate the stomach.
- Direct binding to GLP-1 receptor on gastric mucosal cells leading to delayed gastric emptying.
Benefits of Treatment with GLP-1 Receptor Agonists:
- Weight loss
- Stimulation of insulin secretion from pancreatic beta cells leading to improved hemoglobin A1c
- Decrease in major acute cardiac events due to overall risk factor reduction.
- Decreased glycated hemoglobin level.
- Improved blood pressure control
- Decreased body mass index
- Decreased low density lipoprotein cholesterol level.
- Improved glomerular filtration rate.
- Decreased albumin to creatinine ratio
- Direct stimulation of GLP-1 receptors on the myocardium with improved endothelial function and microvascular perfusion
Adverse effects related to GLP-1 Receptor Agonist Treatment:
- Nausea
- Vomiting
- Diarrhea
- Acute pancreatitis
- Gallbladder and biliary disease
- Rare reactions
- Anaphylaxis
- Angioedema
Here are the risk factors for aspiration that we discussed on the show today:
- Esophageal Pathology which includes achalasia, previous esophagectomy, and tracheal esophageal fistula.
- High risk for ileus or bowel dysmotility including acute pancreatitis, recent intra-abdominal surgery, inpatients receiving opioids, and patients with prolonged bed rest.
- Intra-abdominal Obstruction from either gastric outlet, small bowel, or colonic.
- Emergency cases
- Cases with prolonged duration or complexity
- Pregnancy
- Active GI Bleed
- And finally, Known, suspected or induced gastroparesis and this includes longstanding diabetes, neuromuscular disorders, and medications including the topic for our podcast today, GLP-1 agonists.
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© 2023, The Anesthesia Patient Safety Foundation
Hello and welcome back to the Anesthesia Patient Safety Podcast. My name is Alli Bechtel, and I am your host. Thank you for joining us for another show. We are so excited about this show today. Recently, anesthesia professionals have raised concerns related to patients taking Semaglutide and other GLP-1 Agonists medications and the risk for aspiration. These are newer medications, and this has led to a new threat to anesthesia patient safety.
Before we dive into the episode today, we’d like to recognize ICU Medical, a major corporate supporter of APSF. ICU Medical has generously provided unrestricted support to further our vision that “no one shall be harmed by anesthesia care”. Thank you, ICU Medical – we wouldn’t be able to do all that we do without you!”
We are taking a break from the June 2023 APSF Newsletter to bring you this special article between issues. Our featured article today is “Are Serious Anesthesia Risks of Semaglutide and Other GLP-1 Agonists Under-Recognized? Case Reports of Retained Solid Gastric Contents in Patients Undergoing Anesthesia” by William Beam and Lindsay Guevara. This article was published on June 8, 2023. To follow along with us, head over to APSF.org and click on the Newsletter heading. Second one down is Articles between issues. Then, scroll down until you get to our featured article today. I will include a link in the show notes as well.
Before we get into the article, we are going to hear form William Beam, one of the authors. I will let him introduce himself now.
[Beam] “My name is William Brian Beam, and I’m an anesthesiologist and critical care consultant at Mayo Clinic in Rochester, Minnesota.”
[Bechtel] To kick off the show today, I asked Beam why he is so passionate about this topic. Let’s take a listen to what he had to say.
[Beam] “Ultimately, my passion is for patient safety. In 2018, I helped lead a quality initiative at our institution focused on aspiration events in our practice. And since that time have continued to work on championing efforts to bring awareness to the topic.
Aspiration is one of the leading causes of morbidity and mortality in patients undergoing anesthesia. As anesthesiologist, assessment of our patient’s risk for aspiration is integral to planning a safe anesthetic. Recognizing high-risk patients and planning accordingly is key. The use of GLP-1 agonist seems to be growing exponentially, and I would venture many of us are caring for patients on these medications on a daily basis.
This class of medications has broad benefits for patients, but as we outline in our article, the effects on gastric motility may increase the risk of aspiration in some, even when standard NPO guidelines are followed. I am glad to have the opportunity to raise awareness of this topic and explore the optimal approach to risk mitigation.”
[Bechtel] Thank you so much to Beam for contributing to the show today, sharing his expertise on aspiration events, and being a champion of anesthesia patient safety.
Now, it’s time to get into the article. The authors open with a summary that highlights why glucagon-like peptide, or GLP-1 receptor agonists, are a threat to anesthesia patient safety. This class of medications is used for the treatment of type II diabetes. Recently, GLP-1 agonists were approved for weight loss for patients with obesity and the use of these medications has increased significantly. These medications are involved in direct gastric stimulation of GLP-1 receptors leading to delayed gastric emptying and the potential for retained gastric contents in patients presenting for anesthesia despite following standard fasting guidelines. Let’s take a look at a couple of cases of patients taking GLP-1 receptor agonists who were found to have high volumes of complex gastric contents after following the American Society of Anesthesiologists practice guidelines for preoperative fasting.
The first case involves a 60-year-old patient who presented for an MRI. The patient required sedation for the imaging due to claustrophobia. Other medical history included hypertension and overweight with a BMI of 28. The month prior, the patient started semaglutide which you may know by the name, Ozempic, for weight loss. The last dose was administered 7 days prior to presentation. Despite fasting from solid food for more than 18 hours, the patient described feeling “full” during the preoperative evaluation. A point-of-care gastric ultrasound was performed, which revealed solid gastric contents. The decision was made to cancel the sedation and imaging for fear of high risk of aspiration during the delivery of anesthesia.
The second case involves a 50-year-old patient with past medical history of obesity with a BMI 37, type 2 diabetes, hypertension, and obstructive sleep apnea who was scheduled to undergo a robotic-assisted hysterectomy for endometrial hyperplasia. She previously had gastroesophageal reflux disease, but these symptoms had resolved since she started tirzepatide, which has the brand name of Mounjaro. The last dose was administered 2 days before surgery. Other medications included: metformin, hydrochlorothiazide, pregabalin, oxycodone 5 mg PRN (intermittent use with last dose the day prior to surgery) and sertraline. She had been fasting since the night before surgery.
Anesthesia proceeded with an uneventful induction of general anesthesia and intubation. After intubation an orogastric tube was placed and gastric contents were suctioned. Check out Figure 1 in the article for what was suctioned by the gastric tube at this time. The case was uncomplicated from a surgical perspective. After the surgery was completed, the patient was transferred to the transport bed and sat up in preparation for emergence. Just before the patient was ready for extubation, she developed large volume emesis of particulate matter that was consistent with what she reported eating several days prior to surgery. You can check out Figure 2 in the article to see the contents of the suction canister. The good news is that the endotracheal tube remained in place at this time and the patient’s airway was protected. After the emesis was cleared, the patient was extubated without further events. She was closely observed in the PACU and did not have evidence to suggest gastro-pulmonary aspiration and was therefore, discharged home later that day.
Have you taken care of a patient being treated with a GLP-1 receptor agonist medication recently? Are you seeing more patients on these medications? Have you witnessed any similar cases? Let’s continue in the article to learn more.
So, why are we seeing more patients being prescribed GLP-1 receptor agonists now? These medications have been considered a “breakthrough” for the treatment of weight loss. GLP-1 receptors are expressed in the gastrointestinal tract, pancreas, heart, liver, and brain and stimulation of these receptors leads to weight loss, improved glycemic control in diabetic patients, and improved cardiac and renal outcomes. The primary mechanism of action is likely due to activation of vagal afferent nerves that innervate the stomach and direct binding to GLP-1 receptor on gastric mucosal cells leading to delayed gastric emptying. For diabetes treatment, there is the dual benefits of weight loss and stimulation of insulin secretion from pancreatic beta cells leading to improved hemoglobin A1c. The decrease in major acute cardiac events is likely related to overall risk factor reduction with decreased glycated hemoglobin level, improved blood pressure control, decreased body mass index, decreased low density lipoprotein cholesterol level, improved glomerular filtration rate, and decreased albumin to creatinine ratio. There may also be some direct stimulation of GLP-1 receptors on the myocardium leading to improved endothelial function and microvascular perfusion.
Side effects from these medications include nausea, vomiting, or diarrhea, but these symptoms may decrease over time with continued use. Other adverse effects may include acute pancreatitis and gallbladder and biliary disease including cholecystitis. Rare reactions may include anaphylaxis and angioedema.
This class of medications has important benefits for patients with obesity and diabetes, but keep in mind that there may be serious anesthetic risks as well. We know that GLP-1 receptor agonists act to delay gastric emptying. This may then lead to high volumes of complex gastric contents even after fasting for the appropriate time according to the ASA guidelines. That was certainly the case for the two patients that we discussed earlier who were taking GLP-1 receptor agonists to treat diabetes and help with weight loss. There is a real risk to patient for aspiration and this may be a devastating complication. Did you know that it is in the top three adverse events related to airway management in the ASA closed claims project?! Aspiration is most often due to passive or active regurgitation of gastric contents. It is imperative that we are able to recognize patient who have an increased risk for increased gastric volume in order to deliver a safe anesthetic and keep patients safe from aspiration.
Now, it’s time for a medication review. So, grab your notebooks and pencils. Check out Table 1 in the article which contains a list of common GLP-1 Receptor agonists. All of these medications undergo renal elimination.
- First up is Exanetide which is administered as a subcutaneous injection either twice daily for immediate release or weekly for extended release and has a half-life of 3 hours. This medication is associated with immune-mediated thrombocytopenia.
- Next is Lixisenatide which is no longer available in the United States. This medication is administered as a subcutaneous injection daily and has a half-life of three hours.
- Semaglutide is next which you may know by the brand names of Ozempic or Wegovy. The SubQ formulation is approved for weight loss and is administered weekly. There is also an oral formulation administered daily that is used for diabetes management. The half-life is the longest in this class of medications at 7 days.
- Another medication that has been approved for weight loss is Liraglutide which is administered as a daily subcutaneous injection and has a half-life of 12.5 hours.
- Dulaglutide, with the brand name Trulicity, is administered as a subcutaneous injection weekly and has a half-life of 4.5 days.
- Last on the list is a combination medication that is a GLP-1 and GIP, or glucose-dependent insulinotropic polypeptide receptor, agonist that has also been approved for weight loss and is administered as a weekly subcutaneous injection. The half-life is also quite long at 5 days.
Be on the lookout for these medications during your preoperative evaluation.
We have talked about how patients taking GLP-1 receptor agonists are at increased risk for delayed gastric emptying and having complex gastric contents when they present for anesthesia and surgery which places these patients at increased risk for aspiration. Before we wrap up for today, we are going to review Table 2 from the article: Risk factors for Aspiration.
Here are the risk factors for aspiration.
- Esophageal Pathology which includes achalasia, previous esophagectomy, and tracheal esophageal fistula.
- High risk for ileus or bowel dysmotility including acute pancreatitis, recent intra-abdominal surgery, inpatients receiving opioids, and patients with prolonged bed rest.
- Intra-abdominal Obstruction from either gastric outlet, small bowel, or colonic.
- Emergency cases
- Cases with prolonged duration or complexity
- Pregnancy
- Active GI Bleed
- And finally, Known, suspected or induced gastroparesis and this includes longstanding diabetes, neuromuscular disorders, and medications including the topic for our podcast today, GLP-1 agonists.
We are out of time for today, but that doesn’t mean that we are done talking about GLP-1 receptor agonists. WE hope that you will join us next week as we continue the discuss pulmonary aspiration and decreasing the risk during anesthesia care. Plus, we are going to talk about the all-new ASA consensus-based guidance on preoperative management of patients (adults and children) taking GLP-1 receptor agonists which was just published on the 29th of June 2023. We will also be hearing from APSF author William Brian Beam again. Mark your calendars and tune in next week.
If you have any questions or comments from today’s show, please email us at [email protected]. Please keep in mind that the information in this show is provided for informational purposes only and does not constitute medical or legal advice. We hope that you will visit APSF.org for detailed information and check out the show notes for links to all the topics we discussed today.
While waiting for the next show to drop, if you have not done so already, we hope that you will rate us and leave a review on iTunes or wherever you get your podcasts. Plus, we hope that you share this podcast with your friends and colleagues and anyone that you know who is interested in anesthesia patient safety. Are you an attending or senior consultant anesthetist or anesthesia professional with a roll in education? Don’t forget to share this resource with any anesthesia trainees or others on the perioperative team to help improve anesthesia patient safety going forward.
Until next time, stay vigilant so that no one shall be harmed by anesthesia care.
© 2023, The Anesthesia Patient Safety Foundation