Episode #266 Protecting the Brain: Perioperative Stroke Prevention

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 to be talking about the excellent articles from the June 2025 APSF Newsletter.

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

Our featured article today is “Perioperative Stroke Prevention: A Review of Recent Guidelines for Noncardiac and Non-neurologic Surgery” by Robert Pranaat and Jacob Nadler. To follow along with us, head over to APSF.org and click on the Newsletter heading. The first one down is the current newsletter. Then, scroll down until you get to our featured article today. I will include the link in the show notes as well.

We have exclusive content from one of the authors to help kick off the show today. Here he is now.

[Nadler] “ Hi, my name is Jacob Nadler and I’m chief of the Neuro Anesthesiology Division within the Department of Anesthesiology and Perioperative Medicine at the University of Rochester in Rochester, New York.”

[Bechtel] I asked Nadler why he is so passionate about this topic. Let’s take a listen to what he had to say.

[Nadler] “ I’m passionate about brain health because neurologic complications impact our patient’s identity and humanity in a way that other serious perioperative complications like infection or kidney injury might not. By maintaining brain health, we’re preserving the essence of who our patients are, their memories, their personality, their ability to connect with their friends and family.

To me, brain health is not just a medical concern, but a deeply personal and philosophical one. This area offers tangible opportunities to avoid what I see as really existential complications.”

[Bechtel] Thank you so much to Nadler for contributing to the show today and helping to highlight how important this topic is for anesthesia professionals. The stakes are quite high, and we need to remain vigilant to help keep our patients safe during anesthesia care.

Now, it’s time to get into the article and we’ll get started with a definition. Perioperative stroke is a brain infarction of ischemic or hemorrhagic etiology that occurs during surgery or within 30 days postoperatively. The good news is that this is an uncommon event and may occur in between 0.1 and 0.7% of patients undergoing noncardiac surgery according to data from the American College of Surgeons National Surgical Quality Improvement  Program or ACS-NSQIP. Further investigation into perioperative stroke has revealed the following:

• The greatest risk factors for postoperative stroke included history of stroke including transient ischemic attack, advanced age, anemia with a hematocrit less than 27%, and renal dysfunction.
• The most common time frame was between postoperative days 2 and 9.
• The surgeries with the highest risk were emergency surgery, vascular surgery including carotid endarterectomy and thoracic endovascular aortic repair, and brain surgery.
• The majority of perioperative stoke events in non-cardiac and non-neurological surgery are due to ischemia which may be due to hypotension and low-flow states, previously unknown large-artery stenosis, anemia-associated tissue hypoxia, thrombus, fat, or foreign material embolism, enhanced coagulability, or thrombosis in the setting of systemic inflammation and/or recent discontinuation of antithrombotic medications.

There is an opportunity for enhanced education when it comes to diagnosis and management of perioperative stroke for patients and clinicians. In addition, risk factors may be underrecognized during the preoperative period. There is a study of Canadian anesthesiologists that identified knowledge gaps in anesthesia professionals related to perioperative stroke. Results of this web-based survey study revealed that less than half of the respondents correctly identified the overall incidence of stroke in the perioperative time period and only a quarter knew that thrombosis was the most common etiology. In addition, 64% of respondents believed that the overall risk of dying from perioperative stroke is rare, but the actual stroke-associated mortality-rate is quite high at 25-87%. For most of the respondents, there was a disconnect between knowledge about perioperative stroke and confidence providing care to patients at high risk for stroke. We hope that you will check out the whole study and I will include the citation in the show notes as well.

One question that comes up in preoperative anesthesia clinics around the world is related to the timing of elective surgery for patients who have had a prior stroke. We know that patients with a history of stroke have a higher risk for complications including perioperative stroke, but this risk decreases over time. Let’s look into the literature. There is a 2011 retrospective study evaluating the Danish national health database that found the greatest risk for ischemic stroke and cardiovascular death was within the first 3 months following the initial event for patient undergoing elective surgery. This risk appeared to level off at about 9 months. The 2021 American Stroke Association/American Heart Association guidelines incorporated this data and recommended delaying elective surgery following stroke for 9 months with consideration for surgery after 6 months if the benefits outweighed the risks of waiting.

Fast forward to the 2022 study by Glance and colleagues published in Jama Surgery, “Association of time elapsed since ischemic stroke with risk of recurrent stroke in older patients undergoing elective non-neurological noncardiac surgery.” This is a cohort study of 5.8 million patients that revealed that the risk of stroke and death leveled off after only 90 days between a previous stroke and elective surgery. These results led to new guidelines. In 2024l, a joint guideline by the AHA,ASA, and other international societies for perioperative cardiovascular management of patients undergoing noncardiac surgery was published. The updated guidelines recommend that patients wait at least 3 months after stroke before undergoing noncardiac surgery to help decrease the risk of recurrent stroke and/or major adverse cardiovascular events.

I just want to highlight this recommendation for all anesthesia professionals who may find themselves being asked how long to wait to schedule surgery for patients who have had a stroke. According to the latest guidelines, it is appropriate to wait at least 3 months after the stroke. You can help your entire department stay up to date with the most recent guidelines!!

Speaking of preoperative recommendations, we have more to talk about! Let’s review the guidelines for the prevention of perioperative stroke published by the ASA and AHA in 2021 and the Society of Neuroscience in Anesthesiology and Critical Care or SNACC in 2020. Preoperative recommendations highlight a multidisciplinary approach to preoperative testing and optimization, and appropriate medication management especially when it comes to beta-blockers and anticoagulation. Before we go through the recommendations that are listed in Table 1, I want to highlight some of the difference between these two published guidelines. The SNACC guidelines advise caution with the use of intraoperative metoprolol since it has been associated with perioperative stroke with considerations for using other beta-blockers. The ASA/AHA guidelines recommend continuing beta-blockers.

Other key differences comes from the ASA/AHA guidelines pertaining to the increased risk for perioperative stroke in patients with a patent foramen ovale, the use of the web-based American College of Surgeons Surgical Risk Calculator, and carotid artery revascularization for patients with symptomatic carotid artery stenosis greater than 70% before elective surgery.

The guidelines are also different in the management of patient taking Vitamin K antagonists, but both agree that for patients at high risk for thromboembolic complications, bridging with either therapeutic low molecular weight heparin or intravenous heparin is appropriate. There is further agreement that aspirin, warfarin, and direct oral anticoagulants should be held before elective surgery depending on the bleeding risk and restarted shortly after surgery with heparin bridging only required for high thromboembolic risk cases. Make sure to continue aspirin for patients who have undergone percutaneous coronary interventions. Statin therapy may not reduce the risk of stroke, but may improve other outcomes. You may need to have a discussion with surgeons, anesthesia professionals, neurologists, and other medical professionals to develop a comprehensive preoperative plan for anticoagulation management.

It’s time to through Table 1 in the article for a summary of the preoperative considerations. This is an excellent resource for anyone in a preoperative anesthesia clinic!

First up, the preoperative evaluation. Here are the important considerations:

• All patients should be assessed for their perioperative stroke risk—specifically increased age, renal disease, history of transient ischemic attack/stroke, and patent foramen ovale.
• Patients at higher risk of perioperative stroke should be discussed by a multidisciplinary team.
• Consider using web-based ACS-SRC to assess risk
• Delay noncardiac surgery for ≥3 months following cerebrovascular event.

Next up, there is a recommendation for preoperative optimization:

Perform carotid artery revascularization in patients with symptomatic carotid artery stenosis of greater than 70% before elective surgery.

Finally, we get to medication management which includes the following considerations:

• For Beta blockers: Continue prescribed beta blockers, but do not initiate beta blocker therapy.
• For Aspirin: Do not routinely continue aspirin solely for stroke risk reduction. Consider continuing aspirin in patients at high risk for a major adverse cardiac events (e.g., patients on aspirin for secondary prevention) if benefits outweigh risk of bleeding. Aspirin should be continued if there is a history of percutaneous coronary intervention.
• For Warfarin: Hold for 5–6 days before surgery. Restart 12–24 hours after surgery. Consider heparin or low molecular weight heparin (LMWH) bridging for high thromboembolic risk only. For intermediate risk, bridging is at the clinician’s discretion and bridging is not recommended for low risk.
• For Direct Oral Anticoagulants: For high bleeding risk surgeries hold 3 days prior and restart 2–3 days after surgery. For low bleeding risk surgeries hold 2 days prior and restart 24 hours after surgery. Bridging is based on clinical judgment regardless of bleeding risk.
• Timing of resuming anticoagulants should be discussed by the multidisciplinary team.

Now, it’s time to head into the operating theatre to talk about Intraoperative Considerations to Minimize the risk for stroke. Check out Table 2 in the article to follow along. Here are the important considerations:

• Maintain mean arterial pressures > 70 mmHg, especially in patients with moderate to high perioperative stroke risk
• Pay careful attention to blood pressure gradients between the brain and wherever the blood pressure is being measured in order to avoid hypotension.
• Transfuse to Hgb > 8 g/dl in patients with recent stroke or cerebrovascular disease and maintain Hgb 8–9 g/dl if there is a history of recent stroke, ongoing bleeding, or hemodynamic instability in the presence of known cerebrovascular insufficiency due to occlusion or stenosis. Consider transfusion to Hgb > 9 g/dl if patient is taking a beta blocker to help decrease the risk for perioperative stroke.
• There are no specific recommendations for or against use of regional versus general anesthesia, and no recommendations against use of nitrous oxide or volatile anesthetics versus total intravenous anesthesia. There does appear to be a benefit of regional anesthesia for joint replacement surgery likely due to the differences in blood loss and risk of thromboembolism.
• Maintain normocarbia.
• And maintain serum blood glucose 130–180 mg/dL.

We have made it out of the operating room. It’s time for the postoperative recommendations. Let’s turn our attention to Table 3. Here are the recommendations.

If concern for perioperative stroke, obtain emergent brain imaging.

If high suspicion for perioperative stroke on brain imaging, a multidisciplinary group discussion is warranted to recommend either intravenous thrombolytics and/or the use of mechanical thrombectomy.

If the patient is given recombinant tissue plasminogen activator (rtPA), maintain SBP < 180 mmHg and DBP < 105 mmHg.

Additional testing should include an EKG, troponins, and cardiac telemetry for at least the first 24 hours.

Avoid hypotension. Aim for MAP targets > 70mm Hg in patients at moderate to high risk of stroke.

Initiate aspirin therapy in the first 24–48 hours after ischemic stroke onset but this can be delayed until after 24 hours in patients who have received rtPA.

Maintain serum blood glucose 140–180 mg/dL.

Remember, this is a time when anesthesia professionals can have a big impact on keeping patients safe by providing appropriate hemodynamic monitoring and management, ventilator support, and safe patient transport to imaging, procedural rooms, and hospital floors and intensive care units.

Anesthesia professionals need to be aware of the risks for perioperative stroke and be knowledgeable about recommendations and guidelines to help decrease the risk and recognize this complication when it occurs.

Here are the big takeaways:

Delay elective surgery for at least 3 months after stroke.

Consider a multi-disciplinary approach to perioperative optimization and planning for higher risk patients.

For patients with symptoms concerning for perioperative stroke, emergent evaluation is critical with early engagement of a multidisciplinary team.

Before we wrap up for today, we are going to hear from Nadler again. I also asked him what he hopes to see going forward. Let’s take a listen.

[Nadler] “ I can imagine several developments that would significantly improve our perioperative outcomes. Enhanced risk stratification tools, possibly incorporating artificial intelligence and machine learning or individual patient multis will improve our ability to identify high risk patients better Bleeding risk profiles will let us develop more personalized anticoagulation management protocol.

In the or, we might see personalized blood pressure targets based on individual, real-time cerebral monitoring technologies. And I don’t know if we’ll ever find the holy Grail, a neuroprotective drug that can prevent damage in the setting of hypoperfusion, but research into the mechanisms of hibernation and ischemia.

Reperfusion injury might allow us to precondition our at-risk patients or post-condition our patients who do end up having a stroke.”

[Bechtel] Thank you so much to Nadler for contributing to the show today. We are looking forward to the future with more tools to improve perioperative outcomes and help prevent perioperative stroke going forward.

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.

Thank you for tuning in—and if you found this episode valuable, please share it with your colleagues, friends, or anyone interested in improving anaesthesia patient care and safety. Your support helps us reach more listeners and spread awareness about the importance of safety in anaesthesia.

We’re excited to share that the podcast is available on Spotify and YouTube, so it’s easier than ever to listen and share. If you are on Spotify, make sure you click the bell icon to subscribe so that you don’t miss an episode.

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

© 2025, The Anesthesia Patient Safety Foundation