The effect of sedation on weaning following coronary artery bypass grafting: propofol versus oxycodone-thiopental

Background: Propofol has been advocated for sedation in intensive care beca use of superior recovery characteristics. We hypothesised that the use of t wo totally different sedation methods after coronary artery bypass grafting should result in differences not only in extubation time, but also in brea thing pattern and gas exchange during weaning and after extubation. Methods: Thirty patients participated in this randomised and controlled stu dy. We used propofol infusion and oxycodone-thiopental bolus dosage, titrat ed to sedation level 4 or 5 according to Ramsey. Weaning was performed usin g protocol-based pressure support trials. Results: Total (SD) fentanyl dose during operation was 33 (6) mu g.kg(-1) f or propofol and 34 (6) mu g.kg(-1) for oxycodone-thiopental (ns). The targe t sedation was achieved equally with both methods. The time from admission to intensive care unit to extubation was 494 (100) min for propofol and 521 (98) min for oxycodone-thiopental (ns). Weaning times were 63 (24) min and 112 (63) min in the propofol and oxycodone-thiopental groups, respectively (P<0.05). Breathing frequency increased and tidal volume decreased from we aning to 2 h postextubation. Conclusion: Propofol infusion and oxycodone-thiopental bolus dosages, titra ted to the same sedation end point, resulted in similar time from admission to extubation, although the weaning period was shorter in the propofol gro up. In terms of breathing pattern, gas exchange, blood gases and haemodynam ics, the methods were similar. Propofol, despite its attractive pharmacolog ical profile, may offer no clinical benefit in short-term sedation after a moderate dose fentanyl anaesthesia in cardiac surgery. (C) Acta Anaesthesiologica Scandinavica 44 (2000).