Short-term sevoflurane sedation using the anaesthetic conserving device AnaConDa^® after cardiac surgery: feasibility, recovery and clinical issues

Introduction

With the approval of the anaesthetic conserving device (AnaConDa^®), inhalative sedation in the ICU has become feasible [1]. Isoflurane has been investigated in postoperative and critically ill patients using AnaConDa^®[2, 3], whereas sevoflurane sedation has only been reported in small observations [4, 5]. This randomised, single-blinded, BIS-controlled study was to evaluate for the first time sevoflurane via AnaConDa^® compared with propofol, with regard to recovery, sedation quality and consumption of anaesthetics.

Methods

Seventy patients scheduled for elective coronary artery bypass graft surgery were randomised at admission to the ICU to either receive sevoflurane (n = 35) or propofol (n = 35) for postoperative sedation. The primary endpoint was recovery time from termination of sedation (extubation time, spontaneous eye opening and hand grip). Sedation quality (using the Richmond Agitation Sedation Scale, RASS), sevoflurane consumption, duration of ICU and hospital stays, and adverse side effects were documented.

Results

Median recovery times were significantly shorter (P < 0.002) with sevoflurane than with propofol (extubation time: 21.5 min (2–259) vs 150.5 min (22–910)). Mean sevoflurane consumption was 3.2 ± 1.4 ml/hour to obtain end-tidal concentrations of 0.5–1 vol%; mean administration of propofol was 2.4 ± 1.1 mg/kg/hour. Sedation quality was comparable in both groups (RASS -3 to -4), and no serious complications including haemodynamics related to either sedative drug occurred. Length of stay in the ICU was similar in both groups, whereas patients receiving sevoflurane were discharged significantly (P < 0.03) earlier from hospital (10.6 ± 3.3 days vs 14 ± 7.7 days).

Conclusion

Sevoflurane administration via AnaConDa^® is an efficacious and easy titratable way to provide postoperative sedation in the ICU. Recovery from sedation was facilitated with sevoflurane compared with propofol, and resulted in a shorter ventilation time. Sevoflurane sedated patients left hospital a mean 3 days earlier compared with a propofol-based regimen.