The effect of midazolam at two plasma concentrations of hemodynamics and sufentanil requirement in coronary artery surgery.
OBJECTIVE
In this study, the hemodynamics and sufentanil requirement were compared at two midazolam target plasma concentrations in patients undergoing coronary artery bypass grafting (CABG).


METHODS
Prospective, randomized study.


METHODS
University hospital, single institution.


METHODS
Patients undergoing CABG.


METHODS
Patients were randomly assigned to receive midazolam at a target plasma concentration of 150 ng/mL (group 1; n = 10) or 300 ng/mL (group 2; n = 10). Sufentanil infusion was titrated to maintain hemodynamic stability, defined as mean arterial pressure within 15% of baseline values. All patients received preoperative beta-blocking agents. Arterial blood samples of midazolam and sufentanil were analyzed by high-performance liquid chromatography and radioimmunoassay, respectively.


RESULTS
The mean dose of sufentanil (7.5 +/- 1.7 microgram/kg in group 1 v 7.2 +/- 2.5 micrograms/kg in group 2) did not differ. There were no significant differences in hemodynamics between the groups in the period before or after cardiopulmonary bypass (CPB). Before CPB, in two patients in each group, hypertension was controlled with sufentanil only. One patient in group 1 required a vasodilator in addition to sufentanil. No ischemic events occurred before CPB. After CPB, one patient in group 2 required a vasodilator to control hypertension. Two patients in group 2 required treatment with nitroglycerin for myocardial ischemia. Stable plasma concentrations of sufentanil and midazolam were obtained during and after CPB. The midazolam infusion was continued in both groups at a rate of 1.25 micrograms/kg/min during the first 4 postoperative hours. The time to awakening did not differ between the groups (100 +/- 58 minutes in group 1 v 173 +/- 147 minutes in group 2) nor did the plasma concentrations of midazolam (96 +/- 28 ng/mL v 108 +/- 42 ng/mL) at the time of awakening. Intraoperative awareness was not reported.


CONCLUSIONS
In patients undergoing CABG, good hemodynamic control with a similar incidence of hemodynamic interventions was observed at midazolam target plasma concentrations of 150 and 300 ng/mL when coadministered with sufentanil. The sufentanil requirement was identical in both groups. This study suggests that a midazolam plasma concentration of 150 ng/mL is sufficient to provide satisfactory hemodynamic control and to avoid intraoperative awareness.
van der Maaten
J M
JM
Department of Anesthesiology, University Hospital Groningen, The Netherlands.
Epema
A H
AH
Huet
R C
RC
Hennis
P J
PJ
D000759:Adjuvants, Anesthesia / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology; D000762:Anesthesia Recovery Period; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D006973:Hypertension / Q000517:prevention & control; D008297:Male; D008874:Midazolam / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000517:prevention & control; D005996:Nitroglycerin / Q000627:therapeutic use; D011446:Prospective Studies; D017409:Sufentanil / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology; D014665:Vasodilator Agents / Q000627:therapeutic use; D014851:Wakefulness / Q000187:drug effects
D000759:Adjuvants, Anesthesia; D000319:Adrenergic beta-Antagonists; D000701:Analgesics, Opioid; D018686:Anesthetics, Intravenous; D014665:Vasodilator Agents; D017409:Sufentanil; D005996:Nitroglycerin; D008874:Midazolam