The Effects of Adding Intrathecal Midazolam to Bupivacaine in Spinal Anesthesia

Abstract

Aim: To study of intrathecal bupivacaine with and without midazolam to assess its effect on the onset, duration of sensory and motor block in lower limb surgery. Place and Duration of Study: Fatemi Hospital, Ardebil University of Medical sciences, Iran. From March until September 2014. Methodology: Eighty patients were randomly allocated to two groups: 40 patients in the control group received 3 ml of 0.5% bupivacaine plus 0.4 ml of 0.9% saline intrathecally; 40 patients in the midazolam group received 3 ml of 0.5% bupivacaine plus 0.4 ml (2 mg) midazolam. The onset, duration of sensory/motor block, side effects, sedation score and time for request for first rescue analgesia were noted in two groups. Data collected by questionnaires and the data were extracted and analyzed by SPSS software with Ch-square and T-tests. Results: The deference in onset of sensory and motor block between groups was not significant (p>0.05). The duration of sensory and motor block was prolonged in the midazolam group significantly (p-value =0.005, p-value = 0.014 respectively). There were no episodes of hypotension, bradycardia, pruritus, vomiting and urinary retention in any patients. Incidence of nausea and sedation score was comparable in the two groups. Sedation score in the Midazolam group (3 patient had grade 1 sedation, 35 patients had grade 2 sedation and 2 patients had grade 3) was slightly higher than control group (1 patient had grade 1 sedation, 32 patients had grade 2 sedation and 7 patients had grade 3) (p=0.05). Request time for first rescue analgesia (Diclofenac) was longer in patients who received midazolam (147.38 versus 215.88, p-value<0.001). Conclusion: Intrathecal midazolam increased the duration of sensory and motor block without increasing side effects.