Decrease in Blood Pressure During Thrombectomy Under General Anesthesia Influences Outcome

HOUSTON—Among patients who undergo thrombectomy under general anesthesia, a decrease in blood pressure during treatment is associated with worse functional outcome, according to research presented at the International Stroke Conference 2017. The data suggest the importance of stringent blood pressure targets for improving outcome in patients treated under general anesthesia, said Kilian M. Treurniet, MD, a physician-researcher at the Academic Medical Center in Amsterdam.

Kilian M. Treurniet, MD

The MR CLEAN trial indicated that intra-arterial treatment, including mechanical thrombectomy, is an effective and safe treatment for acute ischemic stroke. The investigators noticed, however, a loss of treatment effect when the procedure was performed on patients under general anesthesia. The researchers hypothesized that decreases in blood pressure might explain this loss of effect, said Dr. Treurniet.

To test this hypothesis, he and his colleagues performed a post hoc analysis of the MR CLEAN data to examine whether decreases from baseline in blood pressure during intervention under general anesthesia were associated with functional outcome. Patients were included in the analysis if their baseline blood pressure had been recorded and if they had regular blood pressure measurements during induction and maintenance anesthesia. The investigators focused on mean arterial pressure on the presumption that it most closely approximates cerebral perfusion pressure. The primary outcome was modified Rankin Scale (mRS) score at 90 days. The investigators performed a primary analysis before adjusting the data for known prognostic factors such as NIH Stroke Scale score and occlusion location.

In all, 60 patients treated under general anesthesia were included in the analysis. Age, sex, and occlusion location were similarly distributed in this population, compared with the larger MR CLEAN population. The majority of patients received propofol as an induction anesthetic and sevoflurane as a maintenance anesthetic.

At baseline, patients’ median systolic blood pressure was 140 mm Hg, and median mean arterial pressure was 100 mm Hg. The average decline in mean arterial pressure during the intervention, compared with baseline blood pressure, was 17 mm Hg. Patients with greater decreases in blood pressure had higher mRS scores at 90 days. Few patients in the analysis had low mRS scores, however, which makes the estimation of the association less precise, said Dr. Treurniet.

In the primary analysis, average mean arterial pressure during the intervention and lowest mean arterial pressure during the intervention were significantly associated with functional outcome. After adjustment, the association between average mean arterial pressure and functional outcome remained significant.

One of the limitations of the analysis is that the data came from nine centers and thus were heterogeneous. Blood pressure was not measured with the same frequency at every center. In addition, the sample size was small, and patients were not randomized to general anesthesia or to local anesthesia. Baseline blood pressure was based on a single manual measurement that could incorporate variability. Finally, the centers used invasive and noninvasive measurements during the procedure, and this heterogeneity could have influenced the results, said Dr. Treurniet.

“A decrease in mean arterial pressure during intervention under general anesthesia is associated with worse outcome in our study,” he added. “It might be that blood pressure management in those patients is of the utmost importance. We are looking forward to possible post hoc analyses of the SIESTA trial on this topic, and the upcoming results of the GOLIATH trial for [more] information.”

—Erik Greb

Suggested Reading

Simonsen CZ, Sørensen LH, Juul N, et al. Anesthetic strategy during endovascular therapy: General anesthesia or conscious sedation? (GOLIATH - General or Local Anesthesia in Intra Arterial Therapy) A single-center randomized trial. Int J Stroke. 2016;11(9):1045-1052.

Sivasankar C, Stiefel M, Miano TA, et al. Anesthetic variation and potential impact of anesthetics used during endovascular management of acute ischemic stroke. J Neurointerv Surg. 2016;8(11):1101-1106.

Treurniet KM, Berkhemer OA, Immink RV, et al. A decrease in blood pressure is associated with unfavorable outcome in patients undergoing thrombectomy under general anesthesia. J Neurointerv Surg. 2017 Apr 12 [Epub ahead of print].

Whalin MK, Lopian S, Wyatt K, et al. Dexmedetomidine: a safe alternative to general anesthesia for endovascular stroke treatment. J Neurointerv Surg. 2014;6(4):270-275.