1Assistant Professor, Dept of Anaesthesiology & Critical Care, Chettinad Hospital & Research Institute, Chennai, India. Email: roshiniog@gmail.com
2Assistant Professor, Department of Anaesthesia, Dhanalakshmi Srinivasan Institute of Medical Science and Hospital, Thuraiyur Road, Perambalur, India. Email: Babylightpink@gmail.com
3Assistant Professor, Department of Anesthesiology, Aarupadai Veedu Medical College and Hospital, Kirumambakkam, Puducherry, India. Email: maruthirao909@gmail.com
*Corresponding Author: Dr Roshini Devi, Assistant Professor, Dept of Anaesthesiology & Critical Care, Chettinad Hospital & Research Institute, Chennai, India. Email: roshiniog@gmail.com
Background: Intrathecal bupivacaine is widely used for spinal anaesthesia in lower abdominal surgeries. However, its limited postoperative analgesic duration necessitates the use of adjuvants. Among the various intrathecal adjuvants, fentanyl (a lipophilic opioid) and midazolam (a short-acting benzodiazepine with antinociceptive properties) are commonly used, though their comparative effectiveness and safety remain subjects of interest.
Aim: This study aimed to compare the efficacy and safety of intrathecal midazolam and fentanyl as adjuvants to hyperbaric bupivacaine (0.5%) in patients undergoing elective lower abdominal surgeries.
Methods: In this prospective, randomized, double-blind study, 140 ASA I/II patients aged 18–60 years scheduled for elective lower abdominal surgeries were assigned to two groups. Group A received 3 ml (15 mg) of 0.5% hyperbaric bupivacaine + 0.4 ml (2 mg) preservative-free midazolam, while Group B received 3 ml (15 mg) of 0.5% hyperbaric bupivacaine + 0.4 ml (20 µg) fentanyl intrathecally. Key outcomes assessed were onset and duration of sensory and motor blocks, duration of effective analgesia, need for rescue analgesia, hemodynamic changes, and adverse effects.
Results: Midazolam significantly prolonged the duration of sensory and motor block as well as effective analgesia compared to fentanyl (p < 0.001). The requirement for rescue analgesia was lower in the midazolam group. Hemodynamic parameters remained stable across both groups, though fentanyl was associated with a higher incidence of side effects such as pruritus and nausea.
Conclusion: Intrathecal midazolam is a safe and effective alternative to fentanyl as an adjuvant to bupivacaine in spinal anaesthesia, offering prolonged analgesia with fewer side effects.
Keywords: Intrathecal midazolam, Intrathecal fentanyl, Bupivacaine, Spinal anaesthesia, Postoperative analgesia, Lower abdominal surgery
How to cite this article: Roshinidevi P, Selvam P, Rao M. Comparison of intrathecal midazolam versus fentanyl as an adjuvant to bupivacaine for postoperative analgesia in lower-abdominal surgeries under spinal anaesthesia. Int J Drug Deliv Technol. 2026;16(12s): 972-979. DOI: 10.25258/ijddt.16.12s.111
Source of support: Nil.
Conflict of interest: None