Effect of midazolam and butorphanol premedication on inhalant isoflurane anesthesia in mice.
Isoflurane is a representative inhalant anesthesia used in laboratory animals. However, isoflurane mediates respiratory depression and adverse clinical reactions during induction. In the present study, we established a novel balanced anesthesia method in mice that combined isoflurane anesthesia with midazolam and butorphanol (MB). Thirty-four male C57BL/6J mice received either isoflurane alone or isoflurane with an intra-peritoneal MB premedication (3 mg/kg midazolam and 4 mg/kg butorphanol). The minimum alveolar concentration (MAC) in each group was evaluated. Induction time and adverse clinical reactions were recorded in each group. Core body temperature, heart rate, respiratory rate, and oxygen saturation (SPO(2)) were assessed before and for 1 h after induction. Premedication with MB achieved a significant reduction in MAC compared with isoflurane monoanesthesia (isoflurane, 1.38 ± 0.15%; isoflurane with MB, 0.78 ± 0.10%; P<0.05). Induction time was significantly shortened with MB premedication, and adverse reactions such as excitement or incontinence were observed less frequently. Furthermore, isoflurane anesthesia with MB premedication caused increase of respiratory rates compared to isoflurane monoanesthesia. No significant decrease of SPO(2) was observed in MBI anesthesia, while a decrease in SPO(2) was apparent with isoflurane monoanesthesia (baseline, 98.3% ± 1.1; 10 min after induction, 91.8 ± 6.4%; P<0.05). In conclusion, premedication with MB was effective for the mitigation of respiratory depression induced by isoflurane in mice, with rapid induction and fewer adverse clinical reactions.
Laboratory of Laboratory Animal Science, Azabu University, School of Veterinary Medicine, 1-17-71 Fuchinobe, Chuou-ku, Sagamihara, Kanagawa 252-5201, Japan.
Atsushi
A
Tsukamoto
Mami
M
Iimuro
Reiichiro
R
Sato
Jumpei
J
Yamazaki
Tomo
T
Inomata
D000769:Anesthesia, Inhalation / Q000379:methods*; D018685:Anesthetics, Inhalation / Q000009:adverse effects / Q000493:pharmacokinetics; D000818:Animals; D000830:Animals, Laboratory; D002077:Butorphanol / Q000008:administration & dosage* / Q000494:pharmacology; D007530:Isoflurane / Q000009:adverse effects / Q000493:pharmacokinetics; D008297:Male; D008810:Mice, Inbred C57BL; D008874:Midazolam / Q000008:administration & dosage* / Q000494:pharmacology; D010101:Oxygen Consumption / Q000187:drug effects; D011229:Preanesthetic Medication; D011650:Pulmonary Alveoli / Q000378:metabolism; D012131:Respiratory Insufficiency / Q000139:chemically induced* / Q000517:prevention & control*; D056152:Respiratory Rate / Q000187:drug effects
D018685:Anesthetics, Inhalation; D007530:Isoflurane; D002077:Butorphanol; D008874:Midazolam