Conscious sedation with combined hypnotic agents for implantation of implantable cardioverter-defibrillators

Objectives. The objective of this study was to evaluate the feasibility, safety and efficacy of placing implantable cardioverter-defibrillators (ICDs) in the electrophysiology laboratory using conscious sedation with combined hypnotic agents and deep sedation with etomidate. Background. Implantable cardioverter-defibrillators with transvenous leads permit the use of simplified implantation techniques similar to those used for the insertion of permanent pacemakers. However, implantation of ICDs without general anesthesia has thus far gained limited acceptance. Methods. In 162 patients, conscious sedation during ICD placement was achieved with combined intravenous midazolam, morphine and promethazine (Phenergan). Intravenous etomidate was administered to induce deep sedation for defibrillation threshold testing. First-time implantations were in the prepectoral position (n = 142), but some patients,vith preexisting devices received abdominal implants (n = 20). The results were compared with those of concurrent patients (n = 56) who received prepectoral implants under propofol anesthesia administered by an attending anesthesiologist. Results. The anesthetic protocol was implemented without major intraoperative complications. During deep sedation,vith etomidate, episodes of apnea, hypoxia or arterial hypotension requiring therapeutic intervention did not occur. During a mean (+/-SD) follow-up period of 257 +/- 140 days (median 227, range 14 to 482), there were, among the 162 patients, a total of two nonsudden cardiac deaths-one 71 days and the other 157 days after the operation. There were two nonsudden deaths in the concurrent control subjects (n = 56)-one 13 days and the other 110 days after the operation. Conclusions. Implantation of ICDs under conscious sedation with combined hypnotic agents and deep sedation with etomidate is a safe and effective procedure,vith low perioperative morbidity and low long term complication rates. (C) 1997 by the American College of Cardiology.