Evaluation of intrathecal midazolam (2mg) as an adjuvant to bupivacaine (0.5%) for spinal anaesthesia in orthopaedic surgery: A case control study

Abstract

Spinal anaesthesia is being routinely used for lower abdominal and lower limb surgeries. Bupivacaine is the commonly used anaesthetic agent because of its longer duration of action. Various intrathecal adjuvants like midazolam are sometimes added to enhance the anaesthetic effects and increase the duration of analgesia. We, hereby evaluated the effects of intrathecal midazolam 2mg as an adjuvant to bupivacaine during spinal anaesthesia in orthopaedic surgery. A total of 60 patients of age 20-50 years were randomly divided into two groups: BM-who received 3.2ml bupivacaine and 0.4ml(2mg) midazolam; and BS-who received 3.2 ml bupivacaine and 0.4ml normal saline. Mean duration of analgesia was prolonged in the midazolam group (429.33+/-59.54 min) as compared to controls (252+/-42.22 min) (p=0.00). The number of injection diclofenac as rescue analgesic were also significantly less in BM group. Time to achieve maximum sensory level(T4) was also significantly less in BM group. Time to two segment regression and the duration of motor block were more in the midazolam group. Intrathecal midazolam as an adjuvant significantly prolongs the duration of analgesia and decreases the requirement of rescue analgesia when combined with bupivacaine during spinal anaesthesia. The dose of 2mg seems to safe and effective to achieve the desired results.