Comparative Study on the Effect of Fractional versus Bolus Dose of Levobupivacaine Used in Spinal Anesthesia in Patients Undergoing Lower Abdominal and Lower Limb Orthopedic Surgery: A Prospective Randomized Controlled Trial

Spinal anesthesia is a commonly used technique for lower abdominal and limb surgeries due to its rapid onset and cost-effectiveness. However, it often causes hemodynamic disturbances like hypotension and bradycardia. To mitigate these effects, fractional spinal anesthesia—administering the anesthetic in divided doses—has emerged as a promising technique, allowing gradual onset of sympathetic blockade and greater hemodynamic stability.

Levobupivacaine, the S(-) enantiomer of bupivacaine, is favored for spinal anesthesia due to its reduced cardiotoxicity and better hemodynamic profile. Despite extensive use, most studies evaluating levobupivacaine have focused on bolus dosing, leaving the potential benefits of fractional dosing underexplored.

This prospective randomized controlled trial aims to compare the effects of fractional versus bolus dosing of intrathecal levobupivacaine in patients undergoing lower abdominal and orthopedic limb surgeries. The primary focus is on hemodynamic stability—specifically, the incidence of significant blood pressure drops and vasopressor requirements. Secondary outcomes include onset and duration of sensory/motor blockade, highest block level, postoperative pain, and adverse events.

By investigating a safer, more stable approach to spinal anesthesia, especially for patients with cardiovascular risk, this study seeks to optimize anesthetic techniques for improved patient outcomes and reduced intraoperative complications.