Sevoflurane and Isoflurane – Pharmacokinetics, Hemodynamic Stability and Cardioprotective Effects during Cardiopulmonary Bypass
Objectives
This study aimed to evaluate the pharmacokinetic profiles of sevoflurane and isoflurane during the use of a minimized extracorporal circulation to perform coronary artery bypass graft surgery. Further, cardiovascular stability during bypass and the postoperative release of troponins were evaluated.
Design
Prospective, randomized Study
Setting
University Hospital
Participants
31 adult patients undergoing coronary artery bypass grafting.
Interventions
The pharmacokinetics measurements of the concentration of the volatile anesthetics in the arterial and venous blood, air inlet, air outlet and the gas exhaust of the extracorporeal circulation were taken. Secondary endpoints were cardiovascular stability during bypass, amount of postoperative release of troponin, time to extubation, time to discharge from the intensive care unit and the hospital, and 30-day mortality.
Measurements and Main Results
Thirty patients completed the protocol. The pharmacokinetics of isoflurane and sevoflurane were almost identical with a rapid wash-in (time to reach 50% of arterial steady state) concentrations 0.87 ± 0.97 min and 1.14 ± 0.35 min for isoflurane and sevoflurane, respectively) and a biphasic venous elimination with a terminal half – life of approximately 10 min for both compounds. There was correlation between the gas inlet and the gas exhaust of the extracorporal circulation. No difference in cardiovascular stability was found. High-sensitive troponin concentrations on the first postoperative morning were 0.355 ± 0.312 µg/ml and 0.225 ± 0.111 µg/ml in the isoflurane and sevoflurane groups, respectively (p=0.147).
Conclusions
The study found similar pharmacokinetics regarding wash-in and wash-out for sevoflurane and isoflurane. In addition, no difference in cardiovascular stability was found. The markers of cardiac damage were not different between the two anesthetics. Based on these data, sevoflurane and isoflurane might be used equivalently in patients undergoing CABG surgery with extracorporal circulation.
