Comparing bupivacaine alone to liposomal bupivacaine plus bupivacaine in interscalene blocks for total shoulder arthroplasty: a randomized, non-inferiority trial.

INTRODUCTION: Interscalene brachial plexus blocks are a commonly performed procedure to reduce pain following total shoulder arthroplasty. Liposomal bupivacaine has been purported to prolong the duration of brachial plexus blocks for up to 72 hours; however, there has been controversy surrounding the analgesic benefits of this drug. Our hypothesis was that an interscalene block performed with bupivacaine alone would be non-inferior to a combination of liposomal bupivacaine and bupivacaine with respect to opioid consumption following total shoulder arthroplasty. METHODS: Subjects presenting for primary total shoulder arthroplasty were randomized in a 1:1 ratio to an ultrasound-guided, single-injection interscalene block with either a combination of liposomal bupivacaine and bupivacaine (LB group) or bupivacaine without additive (Bupi group). The primary outcome of this study was 72-hour postoperative cumulative opioid consumption (in oral morphine equivalents) with a non-inferiority margin of 22.5 mg. Secondary outcomes included pain scores, patient satisfaction with analgesia and patient reported duration of sensory block. RESULTS: Seventy-six subjects, 38 from the Bupi group and 38 from the LB group, completed the study. Analysis of the primary outcome showed a 72-hour cumulative geometric mean oral morphine equivalent consumption difference of 11.9 mg (95% CI -6.9 to 30.8) between groups (calculated on the log scale). This difference constitutes approximately 1.5 tablets of oxycodone over 3 days. No secondary outcomes showed meaningful differences between groups. DISCUSSION: Interscalene brachial plexus blocks performed with bupivacaine alone did not demonstrate non-inferiority compared to a mixture of liposomal bupivacaine plus bupivacaine with regards to 72-hour cumulative opioid consumption following total shoulder arthroplasty. However, the difference between groups did not appear to be clinically meaningful.

Pericapsular nerve group (PENG) block for hip arthroscopy: a randomized, double-blinded, placebo-controlled trial.

INTRODUCTION: Arthroscopic hip surgery is associated with significant postoperative pain. Femoral nerve blocks have been shown to improve postoperative analgesia at the expense of quadriceps weakness. The pericapsular nerve group (PENG) block could be an alternative that may improve postoperative analgesia while preserving quadriceps strength. Our hypothesis was that a PENG block would provide superior postoperative analgesia compared with a sham block following arthroscopic hip surgery. METHODS: Subjects presenting for arthroscopic hip surgery were randomized in a 1:1 ratio to either an ultrasound-guided unilateral, single-injection PENG block (PENG group) with 20 mL of 0.5% ropivacaine or a sham injection with 5 mL of 0.9% normal saline (Sham group) prior to receiving general anesthesia. The primary outcome of this study was worst pain score within 30 min of emergence from anesthesia. Secondary outcomes included opioid consumption, patient satisfaction with analgesia, opioid-related adverse events, and persistent opioid use at 1 week. RESULTS: Sixty-eight subjects, 34 from the PENG group and 34 from the Sham group, completed the study per protocol. Analysis of the primary outcome demonstrated a mean difference in pain scores of -0.79 (95% CI -1.96 to 0.37; p=0.17) between the PENG and Sham groups immediately following surgery. No secondary outcomes showed statistically significant differences between groups. DISCUSSION: This study demonstrates that a preoperative PENG block does not improve analgesia following arthroscopic hip surgery. TRIAL REIGSTRATION NUMBER: NCT04508504.