Midazolam-sufentanil vs sufentanil-enflurane for induction of anaesthesia for CABG surgery.
OBJECTIVE
To compare the effects of midazolam-sufentanil (Group I) and sufentanil-enflurane (Group II) anaesthesia on myocardial oxygenation and metabolism in patients with preserved ventricular function undergoing CABG surgery.


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 intubation, followed by an infusion of 2.5-10.0 micrograms.kg-1.min-1. Supplemental sufentanil (cumulative maximum of 5 micrograms.kg-1) was given for adverse haemodynamic responses. Group II (n = 16) received 5 micrograms.kg-1 sufentanil at induction. Additional sufentanil (maximum 5 micrograms.kg-1), and enflurane (0-3% inspired concentration) were administered for adverse haemodynamic responses. Haemodynamics, myocardial oxygen consumption (MVO2), and lactate extraction were determined at the following times: I) awake (AWA), 2) after induction (IND), and 3) after tracheal intubation (ETT).


RESULTS
Systemic haemodynamics and myocardial metabolism were similar at AWA. 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 individual measurement points (Group II: 10/64 vs Group I: 3/64). Myocardial lactate flux demonstrated a deleterious trend in Group II at ETT.


CONCLUSIONS
Compared with sufentanil-enflurane, midazolam-sufentanil anaesthesia resulted in comparable and acceptable haemodynamics and myocardial oxygenation in CABG patients.
Department of Anaesthesia, Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia, Canada.
T
T
Murphy
R W
RW
Landymore
R I
RI
Hall
D000704:Analysis of Variance; D000768:Anesthesia, General; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D001026:Coronary Artery Bypass; D004737:Enflurane / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007442:Intubation, Intratracheal; D007773:Lactates / Q000378:metabolism; D008297:Male; D008874:Midazolam / Q000008:administration & dosage*; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D017409:Sufentanil / Q000008:administration & dosage*; D016276:Ventricular Function / Q000187:drug effects
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D007773:Lactates; D004737:Enflurane; D017409:Sufentanil; D008874:Midazolam