Background: This prospective randomized double-blind study was designed to compare the analgesic efficacy and safety of intrathecal midazolam versus fentanyl as an adjunct to levobupivacaine for total abdominal hysterectomy. 

Methods: Sixty ASA grade I–II female patients undergoing total abdominal hysterectomy were randomly allocated into two groups. Group 1 (LM)– 3 ml of 0.5% isobaric levobupivacaine+2mg(0.4ml) of preservative free midazolam was given and in Group 2 (LF)- 3ml of 0.5% isobaric levobupivbacaine+12.5ug fentanyl(.25ml)+0.15ml of normal saline was given. The onset and duration of sensory and motor blockade, postoperative pain and the time to 1st rescue analgesia was noted. Patients were observed for hypotension, bradycardia, sedation, respiratory depression, pruritus, nausea and shivering. 

Results: The onset of sensory blockade was early in LM group(p- value <0.01). while duration of sensory blockade was comparable between the two groups(p-value >0.05). Onset of motor blockade was again early in LM group as compared to LF group (p value=0.007). The duration of rescue analgesia was significantly prolonged in group LM as compared with group LF (p-value <0.001). The incidence of pruritis was more in group LF while respiratory depression was more in LM group. 

Conclusions: Addition of midazolam to intrathecal levobupivacaine provides early sensory and motor blockade and also prolonged time for rescue analgesia when compared to LF group. The incidence of pruritis was less in LM group while sedation and respiratory depression was more as compared to LF group.