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 use of minimized extracorporeal circulation to perform coronary artery bypass graft surgery. Furthermore, cardiovascular stability during bypass and the postoperative release of troponins were evaluated. DESIGN: Prospective, randomized study. SETTING: University hospital. PARTICIPANTS: The study comprised 31 adult patients undergoing coronary artery bypass grafting. INTERVENTIONS: The pharmacokinetic measurements of the concentration of the volatile anesthetics in the arterial and venous blood, air inlet, air outlet, and gas exhaust of the extracorporeal circulation were recorded. Secondary end-points 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) concentration of 0.87±0.97 minutes and 1.14±0.35 minutes for isoflurane and sevoflurane, respectively, and a biphasic venous elimination with a terminal half-life of approximately 10 minutes for both compounds. There was a correlation between the gas inlet and the gas exhaust of the extracorporeal circulation. No difference in cardiovascular stability was found. High-sensitivity 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 coronary artery bypass graft surgery with extracorporeal circulation.

Additional cross-sectional transesophageal echocardiography views improve perioperative right heart assessment.

BACKGROUND: Right heart failure is an important cause of perioperative morbidity and mortality, and transesophageal echocardiography (TEE) is crucial for its diagnosis. However, only four of the 20 cross-sectional views recommended in current guidelines for intraoperative TEE focus on the right heart. This study analyzed whether incorporating additional views into the standard TEE examination improves assessment of the right heart. METHODS: Sixty patients underwent standard TEE examination after induction of anesthesia. In addition, five views focusing on the right heart were acquired. Offline analysis tested: (1) whether the additional TEE views can be acquired as reliably as standard views including parts of the right heart; whether incorporating additional views improves the assessment of (2) eight or more right ventricular wall segments based on a predefined nine-segment model; (3) the tricuspid or pulmonary valve in two or more planes; and (4) transvalvular tricuspid and pulmonary flow in orthograde fashion. RESULTS: Additional views could be imaged as reliably (88%) as standard views (90%). Incorporating some of the additional views allowed the assessment of eight or more right ventricular segments in 59 (98%) versus 18 patients (30%) by the standard views alone, and of the pulmonary valve in two or more planes in 60 (100%) versus 15 patients (25%). Several additional views improved orthograde assessment of transvalvular pulmonary flow, but not of tricuspid flow. CONCLUSIONS: The additional TEE views focusing on the right heart can be acquired as reliably as standard views. Incorporating three of them into the standard TEE examination improves comprehensive assessment of the right heart.