Background: Midazolam is the only clinically available water – soluble benzodiazepine has been reported to have an antinoceptive effect through neuroaxial pathway . We investigated systematically administrated midazolam
on level and duration on motor and sensory block in spinal anesthesia with lidocaine.
Methods: After obtaining the approval of the local Ethics committee and with written informed consent and under prospective double blind, randomized study, 36 adult ASA 1&2 patients who were scheduled for elective lower
abdomen and lower extremity surgery under spinal anesthesia with 2 ml lidocain 5% were studied. Patients were allocated to two equal groups of receiving midazolam 0.03 mg/kg and fentanyl 1 µg/kg (group 2). Patients were evaluated
for level and duration of sensory and motor block. Statistical analysis was performed using the SPSS soft ware. The T test, Chi- square and two way ANOVA
were used to data analysis.
Results: Sensory block level was T8 and T10 in group 1 and 2 respectively (P=0.02). The duration of sensory block was longer in group 1 (75.1 ± 28 min) than the group 2 (58.8 ± 23.3 min) , but this difference was not statistically significant (P=0.07). Duration of motor block was longer significantly (P=0.01) in group 1
(82.9 ± 27.3 min) than in group 2 (59.1 ± 26.5 min).
Conclusion: Intravenous midazolam can improve the level of sensory block and the duration of motor block in spinal anesthesia without farther increasing the preoperatively complications.
Key Word: Spinal anesthesia, midazolam, sensory block, motor block
