DENVER — General anesthesia may not be necessary during cryoablation procedures for atrial fibrillation, a small study suggested.
Conscious sedation with dexmedetomidine (Precedex) plus some fentanyl and midazolam (Versed) was enough to keep patients comfortable through the procedure without any recollection afterward of the painful phrenic nerve pacing involved, Patricia Gasper, RN, electrophysiology coordinator at Memorial Leighton Heart and Vascular Center in South Bend, Ind., and colleagues found.
The strategy also saved $1,816 per patient on medication alone compared with general anesthesia, the group reported here at the Heart Rhythm Society meeting.
“It’s very safe — during our study of 88 patients, we didn’t have to convert anyone over to general anesthesia from moderate sedation,” Gasper added in an interview with MedPage Today.
Moderate sedation has been standard with radiofrequency ablation, but general anesthesia has become the standard with cryoablation.
“It wasn’t thought we could get the patient comfortable enough with moderate sedation,” Gasper explained.
Because of the possibility of right phrenic nerve palsy as a complication, “you need to pace the phrenic nerve the whole time, which can be very uncomfortable, it’s like chronic hiccuping for the patient.”
Since general anesthesia carries some risks of morbidity and mortality itself, her center switched to conscious sedation kept at a level of 5 on the Ramsay scale.
The strategy included dexmedetomidine with a mean starting dose of 0.50 μg/kg per hour, titrated up to a maximum dose of 0.65 μg/kg per hour at the nurse’s discretion under supervision of the attending physician. No loading was done so as to avoid hypotension.
Mean midazolam dose as an adjuvant to maintain amnesia was 12 mg; mean fentanyl dose for analgesia was 288 μg.
Among the 88 cryoablation cases done between mid-June 2011 when the strategy was started and mid-November 2012, 74 were done without general anesthesia. The other 14 patients did require it because a history of severe obstructive sleep apnea made them poor candidates for moderate sedation.
Interviews the day after ablation with conscious sedation indicated none of the patients remembered phrenic nerve pacing. While there were no conversions to full anesthesia, one developed hypotension with a systolic pressure under 90 mm Hg that was successfully treated with IV ephedrine.
Analysis of cost based on the hospital supply and inventory cost accounting database showed a mean cost of of $123.79 per patient for moderate sedation drugs versus $1,939.94 for general anesthesia, not including physician fees.
“Dexmedetomidine is a safe, efficacious, and cost-effective alternative to general anesthesia in the majority of patients undergoing balloon ablation for atrial fibrillation,” Gasper’s group concluded.
Conscious sedation still needs to be done in an electrophysiology lab with staff trained in administration of the drug, since the series wasn’t large enough to rule out rare serious events, Gasper acknowledged.
Another limitation was that this was just the first report on the strategy. An additional larger, preferably multicenter study is needed, she noted.
Source: MedPage Today.
