Comparison of Low-dose Diluted Hyperbaric Bupivacaine and Standard Hyperbaric Bupivacaine in Subarachnoid Block for Ambulatory Endovenous Laser Ablation of Varicose Vein: A Randomized Controlled Trial

Abstract Background: Low-dose spinal anesthesia represents a highly coveted anesthetic technique for patients undergoing endovenous laser ablation of varicose veins in a day-care setting, given its prompt onset, reliable anesthesia, brief turnover time, and cost-effectiveness. Given that intense motor block is not required for this procedure, this trial compared the efficacy of low-dose diluted hyperbaric bupivacaine with standard hyperbaric bupivacaine in the subarachnoid block for endovenous laser ablation of varicose veins. Methodology: A prospective, randomized controlled trial at a tertiary care hospital, Tamil Nadu, South India. Sixty individuals with varicose veins requiring endovenous laser ablation surgery were split at random into two groups. Group A ( n = 30) got 0.5% hyperbaric bupivacaine 10 mg (2 ml), Group B ( n = 30) got diluted hyperbaric bupivacaine 5 mg (1 ml of 0.5% hyperbaric bupivacaine diluted with an equivalent volume of normal saline) intrathecally. This study evaluated the time to surgical readiness, peak sensory block level, motor block grade, sensory block level at the completion of surgery, duration of motor and sensory blocks, and timing of discharge. Results: The median peak sensory block level for Group A was T6 (T8–T6), whereas for Group B it was T8 (T10–T6), with a P = 0.03. At the conclusion of surgery, the median sensory block level was T6 (T6–T8) for Group A and T8 (T7–T10) for Group B. No patients in either group needed a rescue analgesic. The average timing of discharge for Group B was shorter ( P = 0.00002). Conclusion: For patients receiving endovenous laser ablation therapy for varicose veins, subarachnoid blockade with low-dose diluted hyperbaric bupivacaine (5 mg) offers an effective anesthesia, the best recovery profile, and early hospital discharge.