Background: General anaesthesia (GA) during endovascular thrombectomy (EVT) appears to improve procedural success1. However, an important concern is that fluctuations in blood pressure (BP) during GA may negatively affect stroke outcomes2, particularly when stroke cohorts are predominantly hypertensive (HT). Understanding hemodynamic fluctuations under anaesthesia is critical in improving outcome after EVT.
Aims: We aimed to explore hemodynamic fluctuations during EVT in patients under GA, and any association with functional recovery. Our objective was to determine whether different subsets of population, based on history of HT and baseline BP, exhibited different BP trends under GA.
Methods: Data was collected retrospectively from the stroke registry at Auckland City Hospital. 1078 patients undergoing EVT since 2012, within 6 hours of symptoms or within 24 hours if wake-up stroke, were screened. Exclusion criteria were pre-hospital intubation, incomplete electronic anaesthesia data, or TICI score less than 2a. Exposure variables were baseline, mean procedural (MnBP), nadir BP, change in MnBP from baseline (ΔBP). Primary outcome measure was 90-day modified Rankin Score (mRS).
Results: 427 patients were included for analysis (mean age 67.1±15.6 years, 51.8% males). 53% of normotensives (NT) and 69% of HT had high baseline BP (>150 mmHg). ΔBP was greater in HT vs NT patients (-8±22.5 vs -12.8±24.7 mmHg; p=0.024). Interestingly, regardless of history of HT, the fall in blood pressure was significantly more in patients with high baseline BP (-22.0±20.2 vs 7.1±17.8 mmHg, p<0.001). mRS scores in either groups did not show a significant difference.
Conclusion: Procedural BP falls during EVT procedures are more common in HT subsets. However, baseline BP may be a better indication for larger relative falls in BP than HT history alone. A uniform approach to hemodynamic management may be disadvantageous for these patients. Further research focused on guidelines for BP management in at-risk patients is warranted.