Optimal dose of hyperbaric bupivacaine 0.5% for unilateral spinal anesthesia during diagnostic knee arthroscopy

Abstract

ObjectiveTo determine the dose of hyperbaric bupivacaine 0.5% required for unilateral spinal anesthesia during diagnostic knee arthroscopy.Patients and methodsThis prospective, randomized, clinical study was performed in 80 patients who were assigned to four groups to receive different doses of intrathecal hyperbaric bupivacaine (5 mg, 7.5 mg, 10 mg and 12.5 mg in Groups 1, 2, 3, and 4 respectively). Onset of sensory and motor block, hemodynamic changes, regression of motor block, and incidence of complications were recorded.ResultsUnilateral sensory block was reported in 90% and 85% of patients in Group 1 and Group 2, respectively, but not in any patient in Group 3 and Group 4. Unilateral motor block (modified Bromage scale 0) was reported in 95% of patients in Group 1, 90% in Group 2, and only 5% in Group 3, while no patient in Group 4 showed unilateral motor block. The time required for regression of motor block (Bromage scale 0) was prolonged with higher doses. The incidence of nausea, vomiting, and urine retention was similar in the study groups.ConclusionUnilateral sensory and motor block can be achieved with doses of 5 mg and 7.5 mg hyperbaric bupivacaine 0.5% with a stable hemodynamic state. However, 7.5 mg of hyperbaric bupivacaine 0.5% was the dose required for adequate unilateral spinal anesthesia.

Comparison of clonidine and fentanyl as an adjuvant to bupivacaine in unilateral spinal anaesthesia

“…The difference was not statistically significant between two groups (p> 0.05). These results are similar to the studies of Atef et al 11 The time to first rescue analgesia was (202.33±38.41) min in BC group and (221.33±44.43) min in BF group. This difference was statistically not significant.…”

“…10 0.5% of hyperbaric bupivacaine was chosen in the present study because studies done by Casati et al and Atef et al found that highly concentrated solutions of hyperbaric bupivacaine are not advantageous in obtaining unilateral spinal anaesthesia when a small anaesthetic dose is injected slowly. 10,11 In the present study, the mean time for onset of sensory block, was significantly lower in group BF (3.23±1.01mins) compared to group BC (5.10±1.40mins). Mean maximum cephalad spread of block for T12 was achieved in 63% patients of group BF and 53% patients in group BC.…”

Efficacy of Unilateral Spinal Anaesthesia and Sequential Combined Spinal Epidural Anaesthesia for Surgery of Lower Limb - A Prospective and Comparative Study

“…[2,3] A dose of 10 mg (2 ml) hyperbaric bupivacaine 0.5% is acclaimed to deliver anaesthesia of duration roughly two to three hours for surgeries above the knee. [13,14] Thus, we used 10 mg of 0.5 % hyperbaric bupivacaine for unilateral SA for the block to last approximately two hour in our study. Sequential CSEA practice is a significant improvement in regional blockade.…”

A comparison of different densities of levobupivacaine solutions for unilateral spinal anaesthesia

“…13,14 Clinical studies have shown both agents to be effective at equal doses in spinal anaesthesia. 15---18 In a study which compared 5, 7.5, 10 and 12.5 mg doses of 0.5% bupivacaine for unilateral spinal anaesthesia in knee arthroscopy, the optimal dose was reported to be 7.5 mg. 19 Therefore, the same dose was used in the current study. The difference in density between cerebrospinal fluid (CSF) and local anaesthetic is an important factor in determining the distribution of the solution in the subarachnoid area.…”