Monitored Anesthesia Care for Subcutaneous Cardioverter-Defibrillator Implantation: A Single-Center Experience

Abstract

Background: To date, general anesthesia has been suggested as the preferred approach for implantation of a subcutaneous implantable cardioverter-defibrillator (S-ICD). The purpose of this study was to assess the use of monitored anesthesia care (MAC) for S-ICD implantation. The goals were to assess adequate sedation and analgesia (efficacy endpoints) and major perioperative airway or hemodynamic compromise (safety endpoints). The authors hypothesized that MAC may provide adequate sedation and analgesia and no major perioperative airway or hemodynamic compromise during S-ICD implantation and multiple defibrillation threshold (DFT) testing.

Methods: Prospectively collected data of patients who underwent S-ICD implantation with MAC from 2015 to 2016 were analyzed retrospectively. The efficacy endpoints were the provision of an optimal depth of sedation and analgesia to facilitate S-ICD implantation without intra-procedure patient discomfort or awareness, and the absence of "severe" pain at the lead tunneling and the generator insertion sites post-procedure. The safety endpoints included: (1) periprocedural hypotension, as defined by a mean arterial pressure (MAP)<60 mmHg refractory to conventional pharmacotherapy, (2) heart rate (HR)<45 bpm requiring pharmacologic support, and (3) sedation-induced airway compromise requiring endotracheal intubation.

Measurements: MAP and HR were recorded during S-ICD implantation and DFT testing. The maximum and minimum infusion rates of propofol, supplemental sedatives, and analgesics, and doses of vasopressor and/or inotropic agents administered intra-procedurally were recorded. Post-procedure pain scores also were noted.

Results: Ten patients underwent S-ICD implantation with MAC (mean age, 56 years; 50% men; mean left ventricular ejection fraction was 39%). Implantation of the S-ICD system using MAC was successful in all patients without any major adverse events. The mean baseline MAP was 92.8 mmHg, and the mean end-procedure MAP was 88 mmHg (p = 0.26). When compared to baseline and end-procedure, the mean lowest intra-procedure MAP was significantly lower (67.4 mmHg; p = 0.0001). The mean baseline HR was 65.7 bpm, and the mean end-procedure HR was 70.1 bpm (p = 0.28). When compared to baseline and end-procedure, the mean lowest intra-procedure HR was significantly lower (55.8 bpm; p<0.001). MAC was not associated with airway compromise in any patient, and post-procedure pain was rated as no greater than "mild".

Conclusions: Among a heterogeneous patient population undergoing S-ICD implantation and DFT testing, the use of MAC is efficacious, feasible, and safe.

Keywords: defibrillation threshold testing; depth of sedation; general anesthesia; monitored anesthesia care; subcutaneous implantable cardioverter-defibrillator.

Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.