Intrathecal Injection of Hyperbaric Bupivacaine Versus a Mixture of Hyperbaric and Isobaric Bupivacaine in Lower Abdominal Surgery: A Randomized Controlled Trial.

Background: Bupivacaine hydrochloride is widely used as the primary drug for spinal anesthesia.

Objectives: This research aimed to evaluate the intrathecal administration of both isobaric and hyperbaric bupivacaine (HB) in lower abdominal surgery.

Methods: A randomized, controlled, double-blind trial was conducted on 50 patients classified as American Society of Anesthesiologists (ASA) class I to II, scheduled for lower abdominal surgery under spinal anesthesia.