LONG-TERM SEDATION WITH ISOFLURANE IN POSTOPERATIVE INTENSIVE-CARE INCARDIAC-SURGERY

After cardiac surgery, patients often require prolonged mechanical ven tilation. We studied the effectiveness and potential toxicity of isofl urane sedation in 40 patients undergoing mechanical ventilation after cardiovascular surgery. All patients who received isoflurane (0.5-1.0 minimum alveolar concentration [MAC]) were well sedated by it without significant adverse effects, such as renal, hepatic, or cardiovascular dysfunction. The highest serum inorganic fluoride concentration recor ded was 45 mu mol/L after 98 MAC h. Patients on isoflurane recovered m ore rapidly and were weaned from mechanical ventilation sooner than th ose sedated with intravenous drugs including fentanyl/midazolam. Patie nts who received intravenous sedatives, but not those on isoflurane, o ften showed tachyphylaxis in the early stages, and some exhibited an a bstinence syndrome involving nonpurposeful movements. Patients sedated with isoflurane did not show these two side effects. In conclusion, i soflurane can provide effective long-term sedation for patients after cardiovascular surgery without significant adverse effects.