Postoperative short-term sedation with propofol in cardiac surgery

We conducted a randomized double-blind study to assess the safety and effectiveness of short-term sedation with propofol in adult patients immediately after cardiac surgery. Sixty hemodynamically stable adult patients who underwent cardiac surgery were randomly assigned to receive propofol postoperatively or no postoperative sedation. The propofol group (n = 30) received propofol infusion (1 mg.kg-1.hr-1) immediately after they awoke postoperatively. The infusion rates were adjusted to maintain a sedation level (Ramsay score) of 3. Nurses assessed the effectiveness of the sedation according to Ramsay scores; the patients also subjectively evaluated sedation. Postoperative pulmonary oxygenation dysfunction (PaO2/FiO2 < 300 mm Hg) was noted in 10 patients receiving propofol and in eight patients in the control group. The dysfunction was greatly improved after overnight ventilator support, and this improvement was not affected by propofol sedation. The propofol group received an average of 13.6 +/- 5.3 hours of propofol infusion, at an average infusion rate of 0.96 +/- 0.16 mg.kg-1.hr-1. Patients receiving propofol remained well sedated (Ramsay score > or = 2) during 99.3% of the study period, while the control patients remained anxious or agitated (Ramsay score, 1) during 12% of the study period. Patients receiving propofol were successfully extubated 9 +/- 4 minutes after cessation of propofol infusion, without complications. The turnover of intensive care unit beds was not delayed by propofol sedation. Subjective evaluations (scored on an analog scale: 0 = nil, 10 = extreme) revealed that patients receiving propofol felt less pain than those in the control group (2.3 +/- 2.7 vs 4.7 +/- 3.1, p < 0.05), had better sleep quality (7.8 +/- 2.9 vs 5.1 +/- 2.9, p < 0.05), and were more satisfied with the care they received (8.3 +/- 2.2 vs 5.8 +/- 3.9, p < 0.05). These findings suggest that propofol infusion is effective for short-term sedation of cardiac surgery patients postoperatively and that an infusion rate adequate to maintain a Ramsay score of 3 may be ideal. Postoperative sedation should be considered for all cardiac surgery patients, not only those with outward signs of anxiety or agitation.