Comparison of ultrasound-guided supraclavicular block according to the various volumes of local anesthetic

Abstract

BackgroundThe ultrasound guidance in regional nerve blocks has recently been introduced and gaining popularity. Ultrasound-guided supraclavicular block has many advantages including the higher success rate, faster onset time, and fewer complications. The aim of this study was to examine the clinical data according to the varied volume of local anesthetics in the ultrasound-guided supraclavicular block.MethodsOne hundred twenty patients were randomized into four groups, according to the local anesthetic volume used: Group 35 (n = 30), Group 30 (n = 30), Group 25 (n = 30), and Group 20 (n = 30). Supraclavicular blocks were performed with 1% mepivacaine 35 ml, 30 ml, 25 ml, and 20 ml, respectively. The success rate, onset time, and complications were checked and evaluated.ResultsThe success rate (66.7%) was lower in Group 20 than that of Group 35 (96.7%) (P < 0.05). The average onset times of Group 35, Group 30, Group 25, and Group 20 were 14.3 ± 6.9 min, 13.6 ± 4.5 min, 16.7 ± 4.6 min, and 16.5 ± 3.7 min, respectively. There were no significant differences. Horner's syndrome was higher in Group 35 (P < 0.05).ConclusionsIn conclusion, we achieved 90% success rate with 30 ml of 1% mepivacaine. Therefore, we suggest 30 ml of local anesthetic volume for ultrasound-guided supraclavicular block.

Ultrasound Guided Supraclavicular Brachial Plexus Block for Arterio-venous Shunt Surgery in Chronic Renal Failure, Comparative Study between Two Volumes of Bupivacaine

“…The average onset times of Group 35, Group 30, Group 25, and Group 20 were 14.3 ± 6.9 min, 13.6 ± 4.5 min, 16.7 ± 4.6 min, and 16.5 ± 3.7 min, respectively. There were no significant differences [8].…”

“…The most important advantage of ultrasound for peripheral nerve block is the ability to confirm local anesthetic spread around the target nerve [8]. The operator can then manipulate the needle under direct vision to the appropriate depth and place the needle tip immediately adjacent to the target nerve [9].…”

“…In both groups, the followings were measured: Onset of sensory block: checked with a needle every 5 min up to 30 min after injection of local anesthetic in all 5 cutaneous nerve distributions Musculocutaneous nerve: lateral side of the forearm, Radial nerve: dorsum of the hand over the 2nd metacarpophalangeal joint, Ulnar nerve: little finger, Median nerve: medial thenar eminence, and Medial cutaneous nerve: medial side of the forearm) [8]. Onset of motor block : checked every 5 min.…”

“…up to 30 min. For motor block evaluation, the following nerves were assessed: Radial nerve (elbow extension against resistance), median nerve (flexion of the distal interphalangeal joint of the second finger), ulnar nerve (abduction of the middle and ring fingers), and musculocutaneous nerve (elbow flexion against resistance) [8]. Success rate: success means complete sensory and motor block.…”

Reduced Hemidiaphragmatic Paresis With a “Corner Pocket” Technique for Supraclavicular Brachial Plexus Block

“…We speculate that these discordant findings could be explained by differences in local anesthetic volume and injection sites. 12,20 For ultrasound-guided SCBPB, the minimal effective volume in 90% of patients was 32 mL for 1.5% lidocaine 21 or 30 mL for 1% mepivacaine, 22 respectively. On the other hand, Renes et al 3 used 20 mL of 0.75% ropivacaine with good success and without hemidiaphragmatic paresis.…”