SAN ANTONIO (EGMN) – Use of general anesthesia for acute stroke patients undergoing an endovascular procedure to open a large intracerebral artery occlusion was linked to significantly worse outcomes and an increased risk of death in two retrospective analyses. Conscious sedation appeared to be the safer alternative, but the results were not definitive, cautioned the two researchers who presented the findings at the International Stroke Conference in San Antonio.
“We feel this needs further study in a prospective manner, as operator preferences of sedation method may have impacted the clinical observations,” Dr. Rishi Gupta said. The findings also showed that during 2006-2009, use of general anesthesia and conscious sedation was highly variable at several major U.S. centers.
Twelve centers contributed data on the 980 patients included in Dr. Gupta’s review. At these centers, general anesthesia was used in 44% of the cases. But use varied from 100% of 89 cases at Massachusetts General Hospital, Boston, to none of 32 patients treated at the University of Louisville, Kentucky.
Dr. Gupta, a neurologist at Vanderbilt University in Nashville, Tennessee, was previously with the Cleveland Clinic Foundation. During 2006-2009, 65 of the 100 stroke patients who underwent an acute endovascular intervention at the Cleveland Clinic received general anesthesia. But after the new analysis was completed, “we shifted and used sedation as our primary modality,” he said in an interview. “What convinced us was that there were no safety differences, no differences in hemorrhages” between general anesthesia and conscious sedation in the analysis.
Dr. Tudor G. Jovin, a neurologist at the University of Pittsburgh, presented the second analysis at the meeting, which showed a significant risk from general anesthesia. “At our center, we used intubation [general anesthesia] routinely until about 2 years ago, and then we changed to conscious sedation,” he said. The shift in Pittsburgh occurred before any findings implicated general anesthesia and intubation in causing adverse outcomes.
The analysis done by Dr. Jovin and his associates used data collected in the Merci Registry at 36 U.S. sites starting in June 2007 after the Merci embolic retriever device entered the U.S. market. The analysis included 625 patients with an average age of 67 and a median National Institutes of Health stroke scale score of 18; just over half (52%) were men. In the multivariate analysis, general anesthesia and intubation were associated with an 87% increase in 90-day mortality, compared with conscious sedation. General anesthesia also was linked to a 48% reduction in the rate of good outcomes, defined as a modified Rankin scale score of 2 or less. Both associations were statistically significant.
“We really don’t have a good handle on [the cause] because we just started to become cognizant of the relationship,” Dr. Jovin said. He noted that less than half the patients in the Merci Registry also were included in Dr. Gupta’s analysis.
In the analysis by Dr. Gupta and his associates, patients had an average age of 66 years and a median NIH stroke scale score of 17. About a third of the patients also received intravenous tissue plasminogen activator. Two-thirds had successful recanalization of their occluded cerebral artery. During the 90 days following endovascular treatment, 30% of the patients died and 37% had a good outcome, defined as a score of 2 or less on the modified Rankin scale.
In a multivariate analysis that controlled for variables such as age, NIH stroke scale score, time to endovascular treatment, success of recanalization, and other parameters, the risk of death was 68% higher in patients who had general anesthesia than in those managed with conscious sedation. The risk for a bad outcome – a modified Rankin scale score of 3 or greater – was more than twice as high in the general anesthesia patients as in the comparator group. Both differences were statistically significant. The analysis showed no significant differences in the rates of symptomatic or asymptomatic hemorrhage between the two subgroups.
Dr. Gupta and his associates also ran the analysis on just the 494 patients with an occlusion at the M1 level of the middle cerebral artery to try to control for imbalances in the occlusion site between the general anesthesia and conscious sedation subgroups. General anesthesia again was linked to a greater than twofold increased risk for a bad outcome.
Reducing intubations in stroke patients undergoing endovascular interventions must be approached carefully because of the important role that general anesthesia plays in ensuring patient comfort.
“We need to work on protocols on safely getting patients through these procedures. One of the real problems has been having patients awake and having unpleasant experiences. Endovascular treatment of intracerebral arteries hurts tremendously,” said Dr. Thomas G. Devlin, chairman of neurology and director of the Southeast Regional Stroke Center in Chattanooga, Tennessee. “We had some patients [treated with conscious sedation] say it was a horrendous experience, and there may be litigation.”
According to Dr. Joseph P. Broderick, investigators in the Interventional Management of Stroke trial have made similar observations of worse outcomes in patients managed with general anesthesia based on prospectively collected data. It is important to know why patients are managed by general anesthesia instead of by conscious sedation. Some patients cannot be treated using conscious sedation. “We need to know whether patients were intubated because that’s how everyone at a center was treated or because there was a specific patient need that might relate to their subsequent death or bad outcome. My guess is that there is a relationship between use of general anesthesia and worse outcome, but I think the relationship probably is not as great as suggested in studies such as Dr. Gupta’s,” said Dr. Broderick, a professor of neurology and director of the Neuroscience Institute at the University of Cincinnati.
Dr. Gupta is a consultant to or has served on the scientific advisory boards of Concentric Medical, CoAxia Inc., and Rapid Medical. Dr. Jovin has been a consultant to or has served on advisory boards for Concentric Medical, CoAxia, Micrus Endovascular Corp., and eV3 Inc. He also has been a consultant to and has an ownership position in Neurointerventions Inc. Dr. Broderick has received research grants and honoraria from and has been a consultant to Genentech Inc.
