GASS
(2022)Objective
To compare the effect of standardized conscious sedation versus standardized general anesthesia on functional outcomes in patients undergoing thrombectomy for large vessel occlusion stroke.
Study Summary
• Patients were randomized to either conscious sedation or general anesthesia, both with a strict protocol for hemodynamic control.
• There was no significant difference in the primary outcome of good functional outcome (modified Rankin Scale score 0-2) at 3 months (36% with sedation vs. 40% with general anesthesia, p=0.474).
• Successful recanalization was higher with general anesthesia (85% vs. 75%), but time to puncture was longer. Safety outcomes were similar.
Intervention
Standardized conscious sedation versus standardized general anesthesia during endovascular thrombectomy for anterior circulation large vessel occlusion stroke. Follow-up was for 90 days.
Study Design
Arms: Array
Outcome
• Successful recanalization was significantly higher in the general anesthesia group (85% vs. 75%, p=0.021).
• Safety was similar, with no difference in the rates of symptomatic intracranial hemorrhage or 3-month mortality.
Bottom Line
In this trial, standardized general anesthesia and standardized conscious sedation during endovascular treatment for stroke resulted in similar functional outcomes at 3 months. The choice of anesthetic strategy did not significantly impact the primary outcome, suggesting clinicians can use either approach.
Major Points
- GASS was a multicenter, single-blind, randomized controlled trial that enrolled 345 patients with large vessel occlusion stroke at four centers in France.
- Patients undergoing endovascular therapy were randomized 1:1 to receive either a standardized conscious sedation protocol or a standardized general anesthesia protocol.
- A key feature of the trial was that both groups had a standardized protocol for intraoperative blood pressure control.
- The primary outcome, a favorable functional outcome (modified Rankin Scale [mRS] score of 2 or less) at 3 months, was not significantly different between groups: 36% in the conscious sedation group versus 40% in the general anesthesia group (P=0.474).
- Patients in the general anesthesia group had a significantly higher rate of successful recanalization (85% vs. 75%; P=0.021) but also experienced longer times from arrival to groin puncture.
- The incidence of symptomatic intracranial hemorrhage and 3-month mortality was similar in both groups.
Study Design
- Study Type
- Investigator-initiated, prospective, multicenter, parallel-group, single-blind, randomized, controlled, superiority trial
- Randomization
- Yes
- Blinding
- Single-blind (patients, nonmedical research staff, the statistician, and the data and safety monitoring committee were blinded; outcome assessors were blinded).
- Sample Size
- 345
- Follow-up
- 3 months
- Centers
- 4
- Countries
- France
Primary Outcome
Definition: Favorable neurologic outcome, defined as a modified Rankin Scale (mRS) score of 2 or less, assessed at 3 months (range 2 to 6 months) after treatment.
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| 40% (66/169) | 36% (63/176) | - (0.69 to 1.19) | 0.474 |
Limitations & Criticisms
- The primary outcome was assessed in a wider time-frame (2 to 6 months) than the planned 3 months for logistical reasons.
- A systematic post-procedural scan at day 1 to assess infarct volume (eg, ASPECTS) was not performed as it was not standard practice at the time of study design.
- The study population had a lower rate of good functional outcome and a higher mortality rate compared to some other stroke trials, which may be related to the older age of the cohort.
Citation
ANESTHESIOLOGY 2022; 136:567-76