Sevoflurane versus isoflurane in patients undergoing valvular cardiac surgery

Objective: To determine if sevoflurane provides hemodynamic and recovery ch aracteristics comparable to isoflurane in patients undergoing surgery for v alvular heart disease. Design: A prospective crossover, dose-response study using sevoflurane and isoflurane before the start of surgery, followed by randomization to sevofl urane or isoflurane for surgery with blinded assessment for recovery. Setting: Tertiary referral cardiac center. Participants: Twenty-seven patients scheduled for elective valve surgery, S urgery consisted of 18 aortic valve and 12 mitral valve replacements, of wh ich 3 patients had 2 valves replaced; 1, tricuspid repair; and 8, coronary artery bypass procedures. Interventions: A pulmonary artery catheter was used to obtain a complete he modynamic profile during the dose-response study before surgery. Transesoph ageal echocardiography was used to confirm the diagnosis, and electrocardio graphy monitored for myocardial ischemia. Measurements and Main Results: Both agents showed similar hemodynamic effec ts at 0.5 and 1.0 minimum alveolar concentration. There was a tendency to d ecreases in heart rate, blood pressure, and cardiac output, whereas filling pressures remained stable with each volatile agent. Electrocardiography di d not detect ischemic changes. Times to eye opening and extubation were sim ilar with both agents, with sevoflurane tending to be earlier than isoflura ne. Conclusion: Sevoflurane showed a tendency to lower heart rates and cardiac index compared with isoflurane, Eye opening and extubation were slightly ea rlier. These findings were not statistically significant, however. Copyrigh t (C) 2001 by W.B. Saunders Company.