Abstract
Many different adjuvants are added intrathecally along with local anaesthetics to prolong intraoperative and postoperative analgesia. Hence, this study aimed to compare intrathecal bupivacaine with fentanyl and bupivacaine with midazolam in lower abdominal and lower limb surgeries. Following permission from the Hospital Ethical Committee (Research Protocol No.: IESC/PGS/2022/143), the study was conducted on a sample of 60 patients, divided into two groups, Group F and Group M, with 30 patients each, representing the American Society of Anaesthesiologist's (ASA) grades I and II. The patients were between the ages of 18 and 60 and featured both males and females, scheduled to undergo elective surgical procedures on the lower abdomen and lower limbs via spinal anaesthesia. Group "F": 3 ml of 0.5% hyperbaric bupivacaine hydrochloride with 0.5 ml (25 mcg) of fentanyl (preservative-free) intrathecally. Group "M": 3 ml of 0.5% hyperbaric bupivacaine hydrochloride with 0.5 ml (2.5 mg) of midazolam (preservative-free) intrathecally. The primary aim was to study the onset of motor and sensory block and duration of analgesia with the addition of midazolam or fentanyl to 0.5% heavy bupivacaine in the sub-arachnoid block. A secondary aim was to evaluate the quality of anaesthesia and postoperative analgesia, determine the haemodynamic stability in the intraoperative and postoperative period in the two study groups, and observe any adverse effects of study drugs. Group F exhibited a substantially longer duration for both sensory (211.5 vs. 154.4 min) and motor blockade (269.8 vs. 214.6 min) compared to Group M, as well as a rapid onset time for both sensory (2.6 vs. 3.3 min) and motor blockade (3.1 vs. 3.9 min). Also, Group F had a significantly longer duration of effective analgesia compared to Group M (266 ± 15.9 vs. 197.6 ± 13.7 minutes). The addition of 0.5 ml (2.5 mg) Midazolam with 0.5% hyperbaric Bupivacaine intrathecally prolonged the duration of anaesthesia and postoperative analgesia; however, fentanyl 0.5 ml (25 mcg) has a more prolonged duration of intraoperative and postoperative analgesia.