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.