Midazolam Sedation during Spinal Anesthesia: Optimal Dosage

• Published in: Nihon Rinshō Masui Gakkai shi Vol. 14; no. 3; pp. 257 - 262
• Main Authors: NISHIYAMA, Tomoki, HIRASAKI, Akihito, ODAKA, Yasuo, SETO, Kozo, IWASAKI, Tatsuo
• Format: Journal Article
• Language: English
• Published: THE JAPAN SOCIETY FOR CLINICAL ANESTHESIA 1994
• ISSN: 0285-4945; 1349-9149
• DOI: 10.2199/jjsca.14.257

Optimal dose of midazolam for sedation during spinal anesthesia was investigated. One hundred and fifteen patients for spinal anesthesia (analgesic area below Th4), 30 to 70 years old, were divided into five groups according to midazolam dose: 0.025mg/kg (27 cases), 0.05mg/kg (25 cases), 0.075mg/kg (23 cases), 0.1mg/kg (25 cases), and 0.125mg/kg (15 cases). Responses to verbal command and ciliary reflex were signifi-cantly more depressed in the 0.05, 0.075, 0.1, and 0.125mg/kg groups than in the 0.025mg/kg group. The sedative effect of 0.025mg/kg of midazolam was therefore considered to be weak. In more than 25% of cases in the 0.075, 0.1, and 0.125mg/kg groups, respiration was depressed by dropped tongue. Respiratory rate increased significantly in the 0.1 and 0.125mg/kg groups. The numbers of cases who required vasopressor, who had body motion or nausea and vomiting did not differ much among the five groups. Blood pressure was more stable in the 0.025 and 0.05mg/kg groups than in the other three groups. The stabilities of circulation and respiration were better in the 0.025 and 0.05mg/kg groups than in the others. It was concluded that the optimal dose of midazolam for sedation during spinal anesthesia in patients aged 30-70 years is 0.05mg/kg.