Effects of Local Anesthetic Volume (Standard Versus Low) on Incidence of Hemidiaphragmatic Paralysis and Analgesic Quality for Ultrasound-Guided Superior Trunk Block After Arthroscopic Shoulder Surgery

Abstract

BACKGROUND: Relative to interscalene block, superior trunk block (STB) provides comparable analgesia and a reduced risk of hemidiaphragmatic paralysis. However, the incidence of hemidiaphragmatic paralysis remains high when a standard volume (15 mL) of local anesthetic is used. This study aimed to evaluate the effects of local anesthetic volume of STB on the incidence of phrenic nerve palsy, as well as its analgesic efficacy following arthroscopic shoulder surgery. METHODS: Patients scheduled for elective arthroscopic shoulder surgery were randomized to receive ultrasound-guided STB using either 5- or 15-mL 0.5% ropivacaine before general anesthesia. The primary outcome was the incidence of hemidiaphragmatic paralysis at 30 minutes after block. The secondary outcomes were pulmonary function, grade of sensory and motor blockade, pain score, opioid consumption, adverse effects, and satisfaction. RESULTS: Relative to standard-volume STB, low-volume STB was associated with a lower incidence of hemidiaphragmatic paralysis after block (14.3 [4.8%–30.3%] vs 65.7 [46.8%–80.9%]; difference 51.4% [95% confidence intervals {CIs}, 29.0%–67.1%]; P < .0001) and at the postanesthesia care unit (9.4% vs 50.0%; difference 40.6 [95% CI, 18.9%–57.7%]; P = .0004). Pulmonary function was also better preserved in the low-volume group than in the standard-volume group. The extent of the sensory and motor blocks was significantly different between the groups. Pain-related outcomes, satisfaction, and any adverse events were not significantly different between the groups. CONCLUSIONS: Low-volume STB provided a lower incidence of hemidiaphragmatic paralysis with no significant difference in analgesic efficacy relative to standard-volume STB for arthroscopic shoulder surgery.

Randomised comparison between superior trunk and costoclavicular blocks for arthroscopic shoulder surgery

“…However, the complete HDP rate of our study was relatively low when compared with a recent study that used 15 ml of local anaesthetic during STB. 8 Third, although there was no serious complication noted in this study, caution is still needed in extending this result into patients with significant respiratory comorbidities. Another potential limitation is the lack of multimodal analgesia at the immediate postoperative period.…”

“…It is important to note that we did not perform an intermediate or superficial cervical plexus block in the current study. The supraclavicular nerve, which is another possible cause of incomplete analgesia in its distribution, can be blocked by cephalad spread to C4 during STB 8 . If combined with CCB, it may have improved postoperative analgesia.…”

“…The supraclavicular nerve, which is another possible cause of incomplete analgesia in its distribution, can be blocked by cephalad spread to C4 during STB. 8 If combined with CCB, it may have improved postoperative analgesia. However, our primary aim was to compare the analgesic effects of the two blocks themselves without any supplements using an equivalent dose of local anaesthetic.…”

Statistical fragility of reporting hemidiaphragmatic paralysis after brachial plexus blocks in randomized controlled trials: a systematic review

“…6.713 L CISB vs HT-ESPB P < 0.001 30 2 HDP in the PACU; 14 vs 0 9 0.3 Zhou et al, [ 36 ] 2022 Anesth Analg. 6.627 L ISB vs CPB P < 0.001 40 0 HDP at 30 min after block; 10 vs 0 4 0.1 Berg et al, [ 31 ] 2022 Anesthesiology 8.986 L Bupi vs liposomal Bupi ISB P = 0.007 26 4 HDP at 24 h; 0 vs 5 1 0.038 Kim et al, [ 27 ] 2021 Pain Physician 4.396 L Conventional vs LVISB P = 0.004 52 0 HDP after block completion; 24 vs 14 4 0.077 Kim et al, [ 24 ] 2021 Anesth Analg. 6.627 L 15 mL vs 5 mL STB P < 0.001 70 0 HDP at 30 min after block; 23 vs 5 9 0.129 Hong et al, [ 6 ] 2021 Sci Rep. 4.996 L CCB vs SCB P = 0.002 ...…”

The Minimum Effective Analgesic Volume of 0.5% Bupivacaine for Ultrasound-Guided Anterior Suprascapular Nerve Block

“…Diaphragm-sparing blocks have been developed, and alternative methods are increasing in popularity. The most popular of these seem to be the anterior suprascapular nerve block (ASSB), supraclavicular block (SCB), upper trunk block, shoulder block, and costoclavicular block (CCB) [17][18][19]. Various randomized controlled studies have been conducted to reduce local anesthetic volumes in regional anesthesia techniques used in shoulder surgery.…”