Midazolam-sufentanil vs sufentanil-enflurane for induction of anaesthesia for CABG surgery

Purpose: To compare the effects of midazolam-sufentanil (Group I) and sufen tanil-enflurane (Group ii) anaesthesia on myocardial oxygenation and metabo lism in patients with preserved ventricular function undergoing CABG surge ly. Methods: Patients randomized to:Group I (n = 16) received midazolam 0.3 mg. kg(-1) at induction of anaesthesia, 0.15 mg.kg(-1) after tracheal intubatio n, followed by an infusion of 2.5-10.0 mu g.kg(-1) min(-1). Supplemental su fentanil (cumulative maximum of 5 mu g.kg(-1)) was given for adverse haemod ynamic responses. Group II (n = 16) received 5 mu g.kg(-1) sufentanil at in duction. Additional sufentanil (maximum 5 mu g.kg(-1)), and enflurane (0-3% inspired concentration) were administered for adverse haemodynamic respons es, Haemodynamics, myocardial oxygen consumption (MVO2), and lactate extrac tion were determined at the following times: I) awake (AWA), 2) after induc tion (IND), and 3) after tracheal intubation (ETT). Results: Systemic haemodynamics and myocardial metabolism were similar at A WA. Heart rate response was attenuated and MVO2 reduced in Group I at IND ( P < 0.05). Following AWA, myocardial lactate production (MLP) occurred more frequently in Group II vs Group I patients (9/16 vs 2/16) and at more indi vidual measurement points (Group II: 10/64 vs Group I: 3/64). Myocardial la ctate flux demonstrated a deleterious trend in Group II at ETT; Conclusions: Compared with sufentanil-enflurane, midazolam-sufentanil anaes thesia resulted in comparable and acceptable haemodynamics and myocardial o xygenation in CABG patients.