Fentanyl Versus Midazolam as an Adjunct to Spinal Anesthesia

A study published on Jan - Feb 2024 has compared adjuvants fentanyl 25 micrograms and midazolam 2mg when added to Levobupivacaine for patients undergoing cesarean section with Midazolam being the superior drug of choice with less side effects. [1] Another study done around our locality at the American University of Beirut compared the postoperative analgesic effect of ketamine and fentanyl when added to bupivacaine in patients undergoing cesarean section with results conclusive of equally effective post cesarean pain control. [2] One study compared intrathecal midazolam 2mg with intrathecal fentanyl 12.5 micrograms with bupivacaine [3], and results elucidated equal surgical analgesia during the operation in contrast to the superior Midazolam 2mg vs the intrathecal fentanyl 25 micrograms when added to levobupivacaine mentioned in the first study. Current literature is void of studies comparing intrathecal fentanyl 25 micrograms vs intrathecal midazolam 2mg when added to bupivacaine for cesarean delivery.

Study objectives:

Comparative studies are available for different adjuvants when administered along with bupivacaine or levobupivacaine, but the specific aim and target of this study is to compare Hyperbaric Bupivacaine 0.5% 12.5 mg with fentanyl 25 micrograms (2 ml) versus Hyperbaric Bupivacaine 0.5% 12.5 mg with midazolam 2mg (2 ml) for cesarean delivery.

Levobupivacaine is not as readily available as bupivacaine in our population. Opioids have significantly more side effects when administered intrathecally including pruritus, respiratory depression, post operatively nausea and vomiting, and any attempt to decrease their usage to improve patient satisfaction without compromising the overall analgesic effect should be pursued. The results from this study could potentially change current practice in our hospital and across local and national areas respectively.

This study aims to provide conclusive data about the superiority of midazolam in reduction of postoperative pain, reduction of postoperative rescue analgesia, the quality of sensory block, and the reduction in side effects when administered with Bupivacaine as opposed to Levobupivacaine which was demonstrated in the study [1] mentioned above.

Inclusion criteria

• Patients aged 18-45 with American Society of Anesthesia (ASA) class II will be included in the study.

Exclusion criteria

• patients with history of opioid substance abuse
• pre-eclampsia or eclampsia
• Gestational Hypertension
• uncontrolled diabetes mellitus
• significant cardiac, renal, and hepatic morbidity (i.e., ASA class III patients).