Stroke is the fifth leading cause of death in the United States, accounting for one out of every 20 deaths per year.1 A stroke is a cerebrovascular event defined as sudden death of brain cells due to lack of oxygen, which is caused by blockage of blood flow (ischemic) or rupture of an artery to the brain (hemorrhagic).2,3 A stroke is an uncommon but potentially fatal complication after surgery.4 Perioperative stroke refers to a stroke occurring within 30 days following surgery.5 While the overall incidence of diagnosed stroke after noncardiac and nonneurologic surgery is between 0.1 and 0.8 percent, the incidence of clinically unrecognized stroke—known as “covert stroke”—may be as high as seven percent for patients 65 years and older.5 Perioperative stroke is associated with significant risk for morbidity and mortality, so clinicians should aim to prevent and detect stroke after surgery.6 Anesthesia providers play a crucial role in preventing and treating perioperative stroke by taking steps before, during and after a procedure.7
Preoperative assessment and preparation are vital to preventing perioperative stroke. The anesthesia professional will begin with an evaluation of the patient’s general risk factors for stroke, which will be exacerbated in the surgical environment.7 These risk factors include older age, male sex, certain ethnicities, heredity, obesity and lifestyle, along with atherogenic (arterial plaque-forming), cardiovascular and thrombotic (blood clot-forming) conditions.7 In addition to identifying risk factors, the anesthesia provider will manage the patient’s use of β-adrenergic receptor blockers (i.e., beta blockers), anticoagulants or antiplatelet drugs.6 For example, continual use of aspirin, an antiplatelet drug, reduces incidence of cardiovascular disease but is controversial during the perioperative period for fear of bleeding complications.7 A study by Taylor et al. found that low-dose, as opposed to high-dose, aspirin use was associated with reduced perioperative stroke risk, suggesting that adequate control of antiplatelet medications is important.8 Furthermore, the anesthesiologist should consider timing of surgery for patients who have had previous strokes.9 Articles by Landercasper et al. and Blacker et al. show that it may be advisable to delay elective surgery for one to three months after a stroke to prevent another cerebrovascular event.10,11 Anesthesia providers are responsible for preoperative risk assessment, medication alteration and possible surgery delay to prevent perioperative stroke.11
During a procedure, anesthesia providers can also take precautions to avoid stroke. This includes good anesthetic technique, such as careful positioning of the head and neck and adequate hydration throughout the procedure.7 While no data exist comparing general versus regional anesthesia in all types of surgery, some studies have found that regional anesthesia for hip and knee arthroplasty may be associated with a lower risk of perioperative stroke than general anesthesia.7 Anesthesia professionals can also provide cerebral protection during surgery, including blood glucose control, hemodynamic stability maintenance, blood transfusion, proper ventilation and intraoperative beta blocker administration.7,9 Thus, anesthetic technique, type of anesthesia and vital signs management may help an anesthesia provider avoid perioperative stroke.
The anesthesia professional must continue to monitor the patient postoperatively, as the majority of perioperative strokes occur at least 24 hours after surgery.12 In fact, some researchers suggest that postoperative events are just as important as intraoperative mechanisms in causing perioperative stroke.13 For example, Bijker and Gelb state that though the exact relationship between intra- and postoperative hypertension and stroke is unclear, hemodynamic stability may be crucial to preventing perioperative stroke.4 Also, though anesthesia providers are not trained in neurology, they—along with other members of the surgical or postoperative medical teams—should be on the lookout for signs of stroke.13 While clinical strokes are marked by face droop, arm weakness or paralysis and jumbled speech,14 covert strokes may be much more difficult to detect and require closer monitoring.14 Both can have devastating long-term effects, as perioperative covert stroke has been associated with an increased risk of cognitive decline one year after non-cardiac surgery.15 Anesthesia providers can aim to prevent perioperative stroke with postoperative vital signs monitoring and quick action if stroke is suspected.
Patients undergoing surgery and anesthesia may be at risk for perioperative stroke, which can have harmful effects on long-term health. Before surgery, anesthesia providers should aim to prevent stroke by performing a risk assessment and adjusting surgery timing and medications. Throughout a procedure, the anesthesiologist should use proper anesthetic technique and drugs, as well as monitor the patient closely. Postoperative care includes management of vital signs and vigilant observation for any signs of stroke. In order to achieve best practices for perioperative stroke prevention, future studies should investigate the role of blood pressure and antiplatelet medications in perioperative stroke.
1. Centers for Disease Control and Prevention. Stroke Statistics. Stroke Facts September 6, 2017; https://www.cdc.gov/stroke/facts.htm.
2. Shiel WC. Medical Definition of Stroke. MedicineNet. Web: MedicineNet, Inc.; January 25, 2017.
3. American Stroke Association. Types of Stroke. 2020.
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14. Heart and Stroke Foundation of Canada. Stroke and dementia. Stroke 2018; https://www.heartandstroke.ca/stroke/what-is-stroke/stroke-and-dementia.
15. Mrkobrada M, Chan M, Cowan D, et al. Perioperative covert stroke in patients undergoing non-cardiac surgery (NeuroVISION): A prospective cohort study. Lancet (London, England). 2019;394(10203):1022–1029.
