Low dose intravenous midazolam for prevention of PONV, in lower abdominal surgery--preoperative vs intraoperative administration.
BACKGROUND
The aim of the present study was to compare anti-emetic efficacy of low dose midazolam premedication (35 microg/kg) 15 minutes before induction of anesthesia with midazolam (35 microg/kg) administered intravenously 30 min before conclusion of surgery, in patients undergoing lower abdominal surgery under general anesthesia.


METHODS
Sixty patients were assigned to one of three equal groups: Group MP (n = 20), which received intravenous midazolam 35 microg/kg in a volume of 3 ml 15 minutes before induction of anesthesia and 3 ml normal saline 30 minutes before extubation. Group MI (n = 20), which received 3 ml normal saline 15 minutes before induction of anesthesia and intravenous midazolam 35 microg/kg in a volume of 3 ml 30 minutes before extubation. Group NS (n = 20), which received 3 ml normal saline 15 minutes before induction of anesthesia plus 3 ml normal saline 30 minutes before extubation. Assessments of the occurrence of postoperative nausea and vomiting (PONV) were made at regular intervals for the first 24 h.


RESULTS
Incidence of PONV was significantly lower in Group MI compared with Group NS and Group MP at 6, 12, 18, and 24 hours after operation (P < 0.05). The time for the first episode of PONV was significantly higher in Group MI compared with Group NS and Group MP (P < 0.05).


CONCLUSIONS
Our results indicated that midazolam 35 microg/kg (2 mg) given intravenously 30 minutes before the end of surgery was more effective in decreasing the incidence of PONV than midazolam premedication 35 microg/kg.
Safavi
Mohammad Reza
MR
Department of Anesthesiology and Intensive Care Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. safavi@med.mui.ac.ir
Honarmand
Azim
A
D000005:Abdomen / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D008874:Midazolam / Q000008:administration & dosage*; D008875:Middle Aged; D010147:Pain Measurement; D020250:Postoperative Nausea and Vomiting / Q000517:prevention & control*; D011300:Preoperative Care / Q000379:methods; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
D018686:Anesthetics, Intravenous; D008874:Midazolam