Having one or more anesthesiologists present during mechanical thrombectomy for acute ischemic stroke optimizes hemodynamics, improves periprocedural complications and facilitates the transition of care, a recent study concluded, prompting the recommendation that an anesthesiologist should be present routinely during endovascular treatment.
“Both anesthetic modality and hemodynamic management are potential contributors to clinical outcomes after mechanical thrombectomy for acute ischemic stroke,” said Gabriela Alcaraz García-Tejedor, MD, a former neuroanesthesia fellow at the University of Toronto. “Anesthetic approach can vary from general anesthesia with intubation to conscious sedation or monitored anesthesia care [MAC] without administration of any sedative agents.
“In many centers, anesthesiologists are not routinely involved during mechanical thrombectomy, except for patients who are unstable or require general anesthesia,” she continued. “So the aim of our study was to review our practice during acute ischemic stroke, with a special focus on the presence of anesthesiologists, anesthetic technique, hemodynamic management and clinical outcomes.”
The researchers conducted a retrospective cohort study involving 143 patients (43% male; median age, 74 years) undergoing endovascular treatment for acute ischemic stroke at the institution between 2012 and 2016. A variety of clinical and procedural variables were collected; multivariate analysis was performed to identify predictors of hemodynamic intervention, failed hemodynamic control (systolic blood pressure <140 and/or >180 mm Hg), in-hospital death and favorable neurologic outcomes (modified Rankin Scale score <2) at discharge.
As Dr. Alcaraz García-Tejedor reported at the 2017 annual meeting of the Canadian Anesthesiologists’ Society (abstract 281164), 98% of cases were of thrombotic origin; IV thrombolysis prior to endovascular treatment was performed in 69.3% of cases. The main occlusion sites were the middle cerebral artery (79.3% of cases), internal carotid artery (6.9%), tandem (6.9%) and multiple (6.9%). The median (interquartile range) National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score (ASPECTS) were 18 (13-22) and 8 (7-10), respectively.
Anesthesiologists were present in 98.6% of procedures. The majority of patients (88.1%) received MAC, with or without sedation. Nine patients received general anesthesia; eight were converted to general anesthesia intraoperatively. “The choice of anesthetic technique and agent were at the discretion of the attending anesthesiologist,” she said. Hemodynamic intervention was needed in 46.9% of patients: 23.1% required intervention for hypotension and 23.8% for hypertension.
“When analyzing the predictors for hemodynamic intervention, we detected that both general anesthesia [odds ratio (OR), 5.88; P=0.01] and systolic blood pressure on hospital admission [OR, 1.02; P=0.019] were related to a higher incidence of hemodynamic intervention,” Dr. Alcaraz García-Tejedor said. It was also found that hemodynamic control failed in 47 patients. The main predictor for both hypotension (OR, 0.92; P=0.001) and hypertension (OR, 1.08; P=0.001) was baseline systolic blood pressure.
Successful revascularization and favorable neurologic status were achieved in 68.5% and 27.9% of patients, respectively. In-hospital death occurred in 16.3% of patients. Of note, the in-hospital mortality rate was significantly higher among patients converted to general anesthesia (50%) than their counterparts who underwent elective general anesthesia (25%), sedation (12.7%) or MAC (20%). “When we did the multivariate analysis, none of the variables studied had an impact on neurological status at discharge.
“This cohort represents one of the highest rates of involvement of anesthesiologists during mechanical thrombectomy for acute ischemic stroke,” Dr. Alcaraz García-Tejedor said. “Hemodynamic intervention is very frequent during mechanical thrombectomy, but successful control is not always easy to achieve. Thus, identifying predictors of hemodynamic intervention might be helpful to detect those high-risk patients who could benefit from a more invasive approach.
“So, we concluded that the role of the anesthesiologist during mechanical thrombectomy is twofold: to facilitate patient immobility and to provide hemodynamic monitoring and support,” she added. “We believe that the presence of an anesthesiologist during mechanical thrombectomy should be routine practice to optimize hemodynamic control and manage high-mortality perioperative complications.”