Comparison of Safety, Efficacy and Duration of Analgesia of Intrathecal Ropivacaine Alone Versus Ropivacaine with Midazolam for Lower Abdominal and Lower Extremity Surgeries

Abstract

Background Spinal anaesthesia is a common anaesthetic technique for lower abdominal and lower extremity surgeries. Many adjuvants have been tried to prolong the duration of analgesia provided by the local anaesthetics when administered intrathecally. Midazolam has been shown to prolong the duration of analgesia when used as an adjuvant, providing the added advantages of mild sedation and amnesia, while being devoid of neurotoxicity, and the adverse effects of opioids.

Aim This study was designed to evaluate the effect of 5% preservative-free midazolam when added to 0.75% isobaric ropivacaine intrathecally in patients undergoing lower abdominal and lower extremity surgeries.

Methods Hundred patients ASA I or II of either gender aged between 18 and 70 years, were randomly allocated to two groups (fifty each). Group I received 3.5 ml of 0.75% isobaric ropivacaine and 0.5 ml of 0.5% preservative free midazolam while Group II received 3.5 ml of 0.75% isobaric ropivacaine and 0.5 ml of normal saline for spinal anaesthesia. Sensory and motor blocking properties, haemodynamics, postoperative analgesia and side effects were evaluated.

Results The total duration of analgesia observed was significantly higher in Group I as compared to Group II, and also the pain score was lower in the Group I. Time for first rescue analgesic required was also significantly delayed in Group I. Sedation level was higher in Group I and cardiovascular changes were comparable in both groups.

Conclusion The addition of preservative-free 5% midazolam to isobaric 0.75% ropivacaineprolonged the duration of analgesia without any adverse effects in patients undergoing lower abdominal and lower extremity surgeries.