Episode #262 Medical Literature Deep Dive: From Infant Intubation to GLP-1 Agonist Risks and More

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. In some parts of the world, it is summer right now and our podcast is giving summer vibes today as we dive into the literature to help cool off. That’s right, we will be checking out the In The Literature Resource from the APSF today so grab your sunscreen and stay tuned.

Before we dive further into the episode today, we’d like to recognize GE Healthcare, a major corporate supporter of APSF. GE Healthcare has generously provided unrestricted support to further our vision that “no one shall be harmed by anesthesia care”. Thank you, GE Healthcare – we wouldn’t be able to do all that we do without you!”

Our first In the Literature Review is a Summary of “Coaching inexperienced clinicians before a high stakes medical procedure: randomized clinical trial.” The summary was complete by Megha Kanjia and published on APSF.org March 3, 2025. To follow along with us, head over to APSF.org and click on the Patient Safety Resources heading. The 8^th one down is In The Literature and from here you can scroll to our featured article. I will include a link in the show notes as well.

This summary comes from the article by Flynn and colleagues, “Coaching inexperienced clinicians before a high stakes medical procedure: randomized clinical trial” published in the British Medical Journal December 2024. This is such an interesting study and article. You can find the citation in the show notes as well.

The focus of this study is “Just-in-time” training which is structured training that occurs right before the performance of a task. This is a common approach in other fields. You may have heard musicians warming up before a performance or seen runners doing strides before a race. However, this type of training is rarely used in medicine, but we all know that there are quite a few high stakes tasks that anaesthesia professionals need to be prepared for. The investigators asked the question, does providing “just-in-time” training to trainees before performing high-stakes medical procedures such as intubating an infant in the operating room, improve outcomes? Here are the study details. It was a non-blinded, randomized clinical trial with 153 trainees including anaesthesiology fellows, anaesthesiology residents, and student registered nurse anesthetists who performed 515 intubations. The trainees were randomized to receive either 10 minutes of “just-in-time” preoperative training on an infant mannequin immediately prior to the intubation or standard training which included unstructured intraoperative instruction on intubation by the attending anaesthesiologist. The primary outcome was first attempt success rate of intubation and the authors found that “just in-time” training increased the likelihood of successful intubation on the first attempt with a first attempt success rate of over 91.4%. That is so cool. The standard training group had a first attempt success rate of 81.6%. The secondary outcomes included complication rates, cognitive load related to the intubation, and competency. Once again, the just-in-time training revealed positive findings with evidence of decreased cognitive load and improved competency. Complications were also lower in the just-in-time group, but the difference was not significant. The authors conclusion is that just-in-time training for inexperienced clinicians is an effective way to teach infant intubation skills that may improve patient safety. These results may be more broadly applicable to teaching other high-stakes clinical procedures. Further studies are needed to inform on coaching considerations during the just-in-time training. It will also be important to evaluate if this type of training can be helpful for experienced clinicians as well. The big takeaway from a patient safety perspective is that in this study, the just-in-time training improved the first pass success rate for a challenging procedure, infant intubation, while decreasing cognitive load and improving competency and this could go along way towards improving anesthesia patient safety especially during high-stakes procedures with trainees in anaesthesiology.

Our next featured literature review was published online on April 14, 2025. It is a summary of “Impact of intravenous antihypertensive therapy on cerebral blood flow and neurocognition: a systemic review and meta-analysis.” The summary was completed by Jayashree Sood and Bhuwan Panday.

The article was published in the British Journal of Anaesthesia in January 2025 and written by Meacham and colleagues. You can find the link for the APSF summary as well as the original article citation in the show notes. Let’s get into the summary.

For a bit of background, intravenous or IV antihypertensives are often administered in the operating room and other acute care settings, but it is unclear what the effects of these medications have on cerebral blood flow and neurocognition. Anaesthesia professionals may administer IV hypertensive medications in the operating theatre or recovery room to quickly reduce blood pressure that is severely elevated in order to reduce complications from the too-high blood pressure. However, there is a concern that these medications may reduce cerebral blood flow. We need to better understand the effects on cerebral blood flow to help keep patients safe.

This is a systematic review and meta-analysis of 50 studies that looked at the effects of different IV antihypertensive medications on cerebral blood flow in humans. Have of the studies evaluated normotensive patients with no intracranial pathology. 9 studies focused on patients who were hypertensive and 16 studies focused on patients with intracranial pathology.

The medications included in the analysis were:

Nicardipine (the most commonly used medication)

Labetalol

Nitroprusside

And Nitroglycerine

When these medications were administered and there was a 20% reduction in mean arterial pressure or MAP, there was no significant change in cerebral blood flow and this was true across many different clinical conditions and patient profiles. In addition, for most of the antihypertensive agents, the decrease in MAP did not correspond to any decrease in cerebral blood flow. This is good news that cerebral blood flow autoregulation remains intact following IV antihypertensive therapy with most of the medications evaluated in the study.

There are a couple notable exceptions. The administration of nitroprusside or nitroglycerin was associated with a reduction in cerebral blood flow. For awake, normotensive patients without intracranial pathology who received these medications, a mean 17% decrease in MAP led to a mean 14% decrease in cerebral blood flow. The authors of the study highlight that nitroprusside and nitroglycerine may impact cerebral perfusion even when used at appropriate clinical doses. We know from historical data in the 1950s that there may be acute neurocognitive changes associated with significant reductions in MAP of about 58% and cerebral blood flow of about 38%. So, we likely need to be careful when administering nitroprusside and nitroglycerine and take into account the clinical context. The study authors share important considerations in their discussion. IV nicardipine likely maintains tissue perfusion including cerebral perfusion due to arteriolar dilation and increased cardiac output effects. IV nitroprusside and nitroglycerine on the other hand may decrease cerebral blood flow due to venodilation leading to reductions in preload and cardiac output. Further investigations are needed to evaluate blood pressure thresholds and parameters for treatment with IV antihypertensive agents as well as to determine optimal antihypertensive treatment depending on cerebral perfusion effects, arteriolar or venous dilation effects and impact on end-organ perfusion. We hope that you will check out the entire article for more information.

Now its time to move on to our third featured article. This is a Summary of “Glucagon-Like Peptide-1 Receptor Agonist Medications and Nonarteritic Ischemic Optic Neuropathy: Is there cause for concern?” The summary was published April 28, 2025 and written by Russel McAllister and Tricia Meyer. There are 5 references listed below the article.

Let’s check out the summary now. The focus of this summary is non-arteritic ischemic optic neuropathy which is associated with ischemia of the optic nerve and is a leading cause of vision loss especially in patients over the age of 50. There is still a lot about this condition that we do not understand. There is a very low incidence that is estimated to be about 2-10 per 100,000 people. We have been learning more about glucagon-like peptide-1 receptor agonists or GLP1 receptor agonists recently since there has been increased use for diabetes, weight-loss, and for reducing morbidity and mortality in patients with cardiovascular disease. There have been a couple studies and reports in the past year that reveal a possible increased risk of nonarteritic ischemic optic neuropathy in patients who were prescribed a GLP1 receptor agonist. We are going to look at some of these.

First up, a single centre retrospective matched cohort study with over 16,000 diabetic patients reported a 34.28 fold increased incidence of non-arteritic ischemic optic neuropathy in patients who were prescribed a GLP1 receptor agonist compared to those who were taking over diabetes medications

Next we have a retrospective e study published in February 2025 of 14 large health databases with over 37 million patients with diabetes. The investigators found a lower increase in non-arteritic ischemic optic neuropathy in the patients with type 2 diabetes taking semaglutide. The incidence ratio was 1.32 to 1.5.

There was one additional study in Denmark of over 400,000 patients with type II diabetes taking once-weekly semaglutide. This was a 5 year longitudinal cohort study of all patients with type II diabetes in Denmark. The use of semaglutide more than doubled the risk for the development of non-arteritic ischemic optic neuropathy.

At this time, there is no data that links these findings to any increased risk of postopertiave3 vision loss, but we need to remain vigilant in this area since ischemic optic neuropathy is a leading cause of postoperative vision loss. There is a careful balance between the risks and benefits. Given that there are strong benefits associated with GLP1 receptor agonis use for the treatment of diabetes obesity, and cardiovascular disease and a very low incidence of non-arteritic ischemic optic neuropathy, the North American Neuro-Ophthalmology Society recommends that patients make no changes in their current use of GLP1 receptor agonist medications. Going forward, we need more research to determine the true risk of non-arteritic ischemic optic neuropathy in patients taking these medications.

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.

Thanks for listening. If you get a chance, we hope that you will share this podcast with your colleagues and all of the members of your perioperative team. You can find the Anesthesia Patient Safety Podcast on iTunes, Spotify, or wherever you get your podcasts. Don’t forget to subscribe to the show that you don’t miss an episode as we continue to work towards improved perioperative patient safety.

Until next time, stay vigilant so that no one shall be harmed by anesthesia care.

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