Acid-base disturbances and its related factors in patients under total intravenous anesthesia

Ischemic preconditioning is a powerful physiological process in which previous exposure to transient cardiac ischemia provides protection against lethal ischemia. Several pharmacological agents can induce the same effects as this process, including drugs used in anesthesia that one of them is Remifentanil. The purpose of this study was to evaluate the effect of Remifentanil preconditioning on coronary artery bypass graft patients. This study is a randomized clinical trial which was performed on 54 patients, Scheduled for elective CABG surgery in year 2009. Patients were randomly divided into two groups. The Remifentanil group received Remifentanil and the control group received normal saline. Then 5 samples were taken from patients at pre-induction, 2, 6, 12 and 24 hours after the release of aortic cross clamp in order to measure cardiac troponin I (cTnI). Postoperative inotropic use in ICU, length of ICU admission and hospital stay were recorded. Data was analyzed using inferential statistical tests including exact Fisher, Chi square, multiple measurements and independent t-test, by SPSS 14 software. There was no significant statistical difference between troponin I level, inotorpe use, and hospital and ICU lengths of stay between the two groups. The protective effect of Remifentanil on myocardium was not proved in this study. Further studies with higher sample volume are necessary for definite confirmation.