Background and purpose Endovascular recanalization in ischemic stroke is often performed under general anesthesia. Some studies have shown a detrimental effect of general anesthesia. The reasons are unknown.

Methods This was an observational study with retrospective and prospective phases. From 2008 to 2010, 60 patients treated by endovascular recanalization due to proximal vessel occlusion were analyzed with regard to ventilation parameters, blood gas values, blood pressure, and clinical parameters (pre-protocol phase). Subsequently, a protocol with target values for end-tidal CO₂ (Petco₂) and systolic blood pressure (SBP) was introduced and prospectively analyzed in 64 patients in 2012 (protocol phase).

Results In the pre-protocol phase, significant hypocapnia (<30 mm Hg), a decrease in SBP after intervention (p<0.001), and an increase in SBP after extubation (p<0.001) were observed. After implementing the protocol in 2012, 63% of Petco₂ values and 55% of SBP values (median) of the duration of intervention were within the predefined range. Severe hypocapnia and hypotension (SBP <100 mm Hg) after the intervention were significantly reduced. Longer duration of Petco₂ values within 40–45 mm Hg, intracerebral hemorrhage, longer door to needle time, older age, unsuccessful recanalization, longer duration of endovascular treatment, and higher cumulative dose of norepinephrine were associated with an unfavorable outcome (modified Rankin Scale score >2). Intracerebral hemorrhage (OR 0.028, p=0.001), age (OR 0.9, p=0.013), and cumulative dose of norepinephrine (OR 0.142, p=0.003) were independent predictors of an unfavorable outcome.

Conclusions In patients receiving endovascular stroke treatment under general anesthesia, the cumulative dose of norepinephrine was an independent predictor of an unfavorable outcome. Further studies are needed to evaluate the optimal management of blood pressure in these patients, and whether avoidance of catecholamines could partly explain the improved outcomes for patients treated under conscious sedation in retrospective studies.