Although general anesthesia is preferred by many anesthesiologists because of a perceived superior safety profile, a study has found that it is no safer than sedation in patients undergoing transcatheter aortic valve replacement (TAVR).
The retrospective trial concluded that compared with sedation, TAVR patients who receive general anesthesia do not have smaller volume requirements, fewer cardiorespiratory perturbations or less vasoactive drug administration.
“I trained at the University of Pennsylvania, which is a fairly sedation-heavy practice when it comes to TAVR,” said Michael Fabbro, DO, assistant professor of clinical anesthesiology at the University of Miami Leonard M. Miller School of Medicine. “But when I came to the University of Miami Hospital, I found that we were doing few sedation cases when it comes to this procedure. When I asked why, most of the answers from the cardiac anesthesiologists centered on a perception that general anesthesia was safer and the anesthetic was more stable. With that in mind, Richard Epstein, MD, and I examined our data to see if there was validity to this thought process.”
Focus on Perioperative Outcomes
Although several recent studies have compared sedation with general anesthesia in TAVR patients and found no differences between the approaches, they focused on adverse outcomes and not specific intraoperative variables related to anesthetic management.
“Outcome data is good,” Dr. Fabbro said, “but it’s not really driving the decision by anesthesiologists to administer sedation or general anesthesia. What’s driving the decision is whether or not the procedure is safe. So we wanted to look at it from this perspective.”
Indeed, the team chose to focus on intraoperative anesthetic management of these patients. They hypothesized that adverse cardiorespiratory events, volume resuscitation, blood loss and the administration of drugs to control blood would all be lower in the general anesthesia group.
The investigators examined the records of 206 consecutive TAVR patients, of whom 150 underwent TAVR via the transfemoral approach. In this cohort, 58 underwent sedation. General anesthesia was performed using a standard induction technique. Sedation was performed primarily using dexmedetomidine; most patients also received preoperative midazolam for anxiolysis. Interestingly, the researchers found that patients who underwent sedation were older than those who received general anesthesia by 2.8 years (95% CI, 0.2-5.5 years). Both groups had similar American Society of Anesthesiologists physical status scores (P=0.49).
As Dr. Fabbro reported at the Society of Cardiovascular Anesthesiologists 39th Annual Meeting (abstract SCA170), patients in the general anesthesia group did not have fewer cardiorespiratory perturbations, including minutes of mean arterial pressure less than 55 mm Hg, heart rate less than 40 beats per minute or oxygen saturation less than 90%. The groups also proved comparable with respect to epinephrine, norepinephrine and dobutamine administration. Finally, volume resuscitation was not less in the general anesthesia group. As such, all three of the researchers’ hypotheses—which tested the superiority of general anesthesia to sedation—were rejected.
Interestingly, patients in the general anesthesia group were more likely to receive at least one transfusion of red blood cells (21/92 vs. three of 58; P=0.005). Furthermore, patients who received general anesthesia were more than twice as likely to be transferred to the ICU with an endotracheal tube in place. Nevertheless, eight sedation patients (13.8%) required conversion to general anesthesia.
Yet, despite the fact that superiority was not demonstrated with regard to the safety of general anesthesia during the intraoperative period, Dr. Fabbro recognized that moving from general anesthesia to sedation for TAVR takes time and effort.
“Such a move really starts with the proceduralists themselves,” he said. “How can they collaborate with the cardiology group to reduce procedure times and make this a successful transition?”
Equally important is the belief among both cardiologists and anesthesiologists at the institution that such a move can be successful. Nevertheless, it was easy for Dr. Fabbro to see why some institutions and practitioners might be leery of the switch.
“People are concerned about things like managing an airway in an out-of-[operating room] environment with limited patient access,” he said. “They’re worried about patients that typically have prohibitive surgical comorbidities, including things like very low ejection fractions and [chronic obstructive pulmonary disease], patients that are predisposed to cardiovascular instability. On top of that, they have a very narrow aortic valve that’s going be instrumented with large devices that are going to create more instability.”
Scott T. Reeves, MD, MBA, was impressed with the results and the potential of sedation techniques to make an increasing impact. “Dr. Micha el Fabbro has added to a growing body of evidence that sedation is not only safe but ultimately may be the preferred anesthetic technique for TAVR,” said Dr. Reeves, who is the John E. Mahaffey, MD, Professor and Chairman of Anesthesia & Perioperative Medicine, at the Medical University of South Carolina, in Charleston.
“Sedation has become the standard across Western Europe and is expanding rapidly within high-volume centers in the United States. One major cost advantage may be the ability to fast-track patients through our health systems by eliminating the need for ICU care and shortening or eliminating the in-hospital stay,” he said.