Levosimendan reduces heart failure after cardiac surgery: a prospective, randomized, placebo-controlled trial.

OBJECTIVE: To investigate whether levosimendan diminishes the incidence of heart failure after cardiac surgery. DESIGN: Prospective, randomized, placebo-controlled clinical study. SETTING: Cardiac surgery operating room and postanesthesia care unit in a university hospital. PATIENTS: Two hundred patients assigned to undergo heart valve or combined heart valve and coronary artery bypass grafting surgery. INTERVENTIONS: Patients were randomized to receive a 24-hr infusion of placebo or levosimendan administered as a 24 µg/kg bolus over 30-mins and thereafter at a dose of 0.2 µg/kg/min. MEASUREMENTS AND MAIN RESULTS: Heart failure was defined as cardiac index<2.0 L/min/m or failure to wean from cardiopulmonary bypass necessitating inotrope administration for at least 2 hrs postoperatively. Heart failure was less frequent in the levosimendan compared to the placebo group: 15 patients (15%) in the levosimendan and 59 patients (58%) in the placebo group experienced heart failure postoperatively (risk ratio 0.26; 95% confidence interval 0.16-0.43; p<.001). Accordingly, a rescue inotrope (adrenaline) was needed less frequently in the levosimendan compared to the placebo group (risk ratio 0.11; 95% confidence interval 0.01-0.89), p=.005. Intra-aortic balloon pump was utilized in one patient (1%) in the levosimendan and in nine patients (9%) in the placebo group (risk ratio 0.11; 95% confidence interval 0.01-0.87), p=.018. The hospital and the 6-month mortality were comparable between groups. There were no significant differences in major organ failures postoperatively. Eighty-three patients were hypotensive and needed noradrenaline in the levosimendan compared to 52 patients in the placebo group, p<.001. The cardiac enzymes (creatine kinase MB isoenzyme mass) indicating myocardial damage were lower in the levosimendan group on the first postoperative day, p=.011. CONCLUSIONS: In the present study, levosimendan infusion reduced the incidence of heart failure in cardiac surgery patients but was associated with arterial hypotension and increased requirement of vasopressor agents postoperatively. Improved mortality or morbidity was not demonstrated.

Midlatency auditory-evoked potentials in the assessment of sedation in cardiac surgery patients.

OBJECTIVES: Midlatency auditory-evoked potentials (MLAEPs) may provide an objective measure of depth of sedation. The aim of this study was to evaluate MLAEPs for measuring sedation in cardiac surgery patients. DESIGN: Prospective study. SETTING: Intensive care unit of a university hospital. PARTICIPANTS: Twenty-two patients scheduled for elective coronary artery bypass grafting. INTERVENTIONS: MLAEPs were obtained at 5 time points: the day before surgery (baseline), 1 hour before surgery, after premedication, postoperatively during deep (Ramsay 6) and moderate (Ramsay 4) sedation, and the day after surgery. MEASUREMENTS AND MAIN RESULTS: The latency of the Nb MLAEP component increased from 44 ms (38-60 ms; median, range) at baseline to 49 ms (41-64 ms) after premedication (p = 0.03) and further to 63 ms (48-80 ms) during deep sedation after surgery (P < 0.01). Although a decreasing clinical level of sedation after rewarming was not associated with a significant change in Nb latency (61 ms [42-78 ms]), the MLAEP NaPa amplitude increased from 0.9 muV (0.4-1.6 microV) to 1.3 muV (0.8-3.9 microV; p = 0.01). Nb latency remained increased the day after surgery (49 ms [37-71 ms]) as compared with baseline (p < 0.01). CONCLUSIONS: MLAEP latencies can reflect subtle changes in auditory perception, while amplitudes seem to change with transition between deep levels of sedation.