Optimizing Outcomes for Mechanically Ventilated Patients in an Era of Endovascular Acute Ischemic Stroke Therapy

The effect of procedural end-tidal CO2 on infarct expansion during anterior circulation thrombectomy

BACKGROUND

Carbon dioxide is a potent cerebral vasodilator that may influence outcomes after ischemic stroke. The objective of this study was to investigate the effect of intraprocedural mean end-tidal CO2 (ETCO2) levels on core infarct expansion and neurologic outcome following thrombectomy for anterior circulation ischemic stroke.

METHODS

A retrospective review was conducted of consecutive patients from March 2020 to June 2021 who underwent mechanical thrombectomy for acute anterior circulation ischemic stroke under general anesthesia and achieved successful recanalization (Thrombolysis in Cerebral Infarction [TICI] ≥ 2b). Only patients with CT perfusion, procedural ETCO2, and postoperative MRI data were included. Segmentation software was used for multi-parametric image analysis. Normocarbia defined as mean ETCO2 of 35 mmHg was used to dichotomize subjects. Univariate and multivariate statistics were applied.

RESULTS

Fifty-eight patients met criteria for analysis. Of these, 44 had TICI 3 recanalization, 9 had TICI 2c, and 5 had TICI 2b. Within this combined recanalization group, patients with mean ETCO2 > 35 had significantly higher rates of functional independence at 90 days. Although patients tended to salvage more penumbra and experience smaller final infarcts when ETCO2 exceeded 35 mmHg, this did not reach statistical significance.

CONCLUSIONS

Stroke patients who underwent successful thrombectomy with general anesthesia achieved higher rates of functional independence when procedural ETCO2 exceeded 35 mmHg. Further studies to confirm this effect and investigate optimal ETCO2 parameters should be considered.

Effect of anesthesia strategy during endovascular therapy on 90-day outcomes in acute basilar artery occlusion: a retrospective observational study

Background and objective

The research on the effect of anesthesia on endovascular therapy (EVT) of acute ischemic stroke is mainly focused on the anterior circulation, and little is known about the data of basilar artery occlusion (BAO). This study aims to investigate the association of anesthesia strategy with 90-day clinical outcomes of patients with acute BAO treated with EVT.

Methods

We reviewed our prospectively collected data from the endovascular treatment database at the Beijing Tiantan Hospital. This included patients with acute BAO who had a documented 90-day modified Rankin Scale (mRS) score from January 2012 to July 2018. Options for EVT included general anesthesia (GA) and conscious sedation (CS) performed by an anesthesia care team in the institution. The recommendation of anesthesia for patients was a joint decision between anesthesiologist and neurointerventionalist according to a pre-designed scheme. Patients who required tracheal intubation for airway protection prior to EVT were excluded. The clinical outcomes we observed were functional independence (mRS ≤2), favorable outcome (mRS ≤3), and mortality at 90 days after the procedure. Univariate and multivariable logistic regression analyses were used to explore the relationship between anesthesia methods and 90-day outcomes.

Results

A total of 187 patients with BAO were treated by EVT in this study. Nine cases requiring emergent intubation prior to EVT were excluded. 139 patients (78.1%) underwent GA and 39 patients (21.9%) underwent CS. In univariate analysis, GA was associated with less functional independence [odds ratio (OR), 0.28; 95% confidence interval (CI), 0.13–0.59] and less favorable outcome (OR, 0.23; 95% CI, 0.10–0.52) than was CS. After adjusting for potential confounders, multivariable analysis showed that there were still significant differences between GA and CS in functional independence (OR, 0.31; 95%CI, 0.10–0.97) and favorable outcome (OR, 0.24; 95%CI, 0.07–0.75).

Conclusion

Our retrospective analysis suggested that the anesthesia strategy may affect outcome, in which general anesthesia may result in less favorable outcomes. Nevertheless, future multicenter randomized controlled trials are needed to confirm our findings.

A decrease in blood pressure is associated with unfavorable outcome in patients undergoing thrombectomy under general anesthesia

BACKGROUND

Up to two-thirds of patients are either dependent or dead 3 months after thrombectomy for acute ischemic stroke (AIS). Loss of cerebral autoregulation may render patients with AIS vulnerable to decreases in mean arterial pressure (MAP).

OBJECTIVE

To determine whether a fall in MAP during intervention under general anesthesia (GA) affects functional outcome.

METHODS

This subgroup analysis included patients from the MR CLEAN trial treated with thrombectomy under GA. The investigated variables were the difference between MAP at baseline and average MAP during GA (ΔMAP) as well as the difference between baseline MAP and the lowest MAP during GA (ΔLMAP). Their association with a shift towards better outcome on the modified Rankin Scale (mRS) after 90 days was determined using ordinal logistic regression with adjustment for prognostic baseline variables.

RESULTS

Sixty of the 85 patients treated under GA in MR CLEAN had sufficient anesthetic information available for the analysis. A greater ΔMAP was associated with worse outcome (adjusted common OR (acOR) 0.95 per point mm Hg, 95% CI 0.92 to 0.99). An average MAP during GA 10 mm Hg lower than baseline MAP constituted a 1.67 times lower odds of a shift towards good outcome on the mRS. For ΔLMAP this association was not significant (acOR 0.97 per mm Hg, 95% CI 0.94 to 1.00, p=0.09).

CONCLUSIONS

A decrease in MAP during intervention under GA compared with baseline is associated with worse outcome.

TRIAL REGISTRATION NUMBER

NTR1804; ISRCTN10888758; post-results.