Midazolam does not antagonize fentanyl-mediated analgesia in surgical patients.
OBJECTIVE
To determine whether midazolam possesses a clinically significant antianalgesic action in surgical patients.


METHODS
Randomized, controlled study.


METHODS
Inpatient anesthesia at a university department of neurosurgery.


METHODS
2 groups of 10 patients each who were scheduled for supratentorial brain surgery, did not have elevated intracranial pressure, and were free from systemic disease.


METHODS
Patients underwent anesthesia induction with hexobarbital, succinylcholine, and pancuronium; anesthesia was maintained with injections of droperidol-fentanyl (Group 1) or with midazolam-fentanyl (Group 2) following a predetermined repetitive dosing schedule, such that fentanyl 0.1 mg was injected upon predominant increases in heart rate, whereas droperidol 2.5 mg or midazolam 2.5 mg was injected upon increases in blood pressure.


RESULTS
Duration of anesthesia and invasiveness of surgery were similar in both groups. The amount of fentanyl required was 0.55 +/- 0.18 mg/hr (mean +/- SD) in Group 1 and 0.53 +/- 0.17 mg/hr in Group 2. Injections of droperidol 7.5 +/- 3.4 mg/hr (Group 1) and midazolam 5.9 +/- 2.3 mg/hr (Group 2) were administered intraoperatively. This redosing regimen was associated with uninterrupted hemodynamic stability, indicating comparable and adequate anesthetic depth. Plasma concentrations of metabolites and hormones indicative of humoral stress activation did not differ between groups.


CONCLUSIONS
Under these clinical conditions, the administration of midazolam, when compared with droperidol, was not associated with signs of any antagonistic or antianalgesic action toward fentanyl-mediated analgesia.
Behne
M
M
Department of Anesthesiology and Resuscitation, Johann Wolfgang Goethe University Clinics, Frankfurt a. Main, Germany.
Lischke
V
V
Asskali
F
F
Probst
S
S
Hermann
R
R
Vettermann
J
J
D000293:Adolescent; D000328:Adult; D000698:Analgesia; D000700:Analgesics / Q000008:administration & dosage / Q000037:antagonists & inhibitors*; D000771:Anesthesia, Intravenous; D001794:Blood Pressure / Q000187:drug effects; D004329:Droperidol / Q000008:administration & dosage; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000037:antagonists & inhibitors*; D006339:Heart Rate / Q000187:drug effects; D006591:Hexobarbital / Q000008:administration & dosage; D006801:Humans; D007430:Intraoperative Care; D008297:Male; D008874:Midazolam / Q000494:pharmacology*; D008875:Middle Aged; D010197:Pancuronium / Q000008:administration & dosage; D013312:Stress, Physiological / Q000097:blood; D013390:Succinylcholine / Q000008:administration & dosage; D015173:Supratentorial Neoplasms / Q000601:surgery
D000700:Analgesics; D006591:Hexobarbital; D013390:Succinylcholine; D010197:Pancuronium; D004329:Droperidol; D008874:Midazolam; D005283:Fentanyl