Liposomal Bupivacaine Plus Bupivacaine Peripheral Nerve Blockade Versus Ropivacaine Plus Dexamethasone Peripheral Nerve Blockade for Arthroscopic Rotator Cuff Repair: a Prospective Randomized Trial

Arthroscopic rotator cuff repair(ARCR) addresses dysfunction and pain in individuals with rotator cuff tears who have failed conservative management. These procedures are typically performed in an outpatient setting. Single shot PNB with long acting local anesthetics have become the foundation of modern multimodal analgesia protocols. The reported analgesic benefits of PNB for shoulder surgery include reduced pain scores, opioid consumption, post-operative nausea and vomiting, improved postoperative recovery and improvement of patient satisfaction. However, standard PNB with bupivacaine or ropivacaine have been associated with rebound pain resulting in a sudden onset of pain that can be refractory to treatment and often necessitates the use of significant quantities of opioids.

Side effects of opioid consumption include nausea, vomiting, sedation, constipation, respiratory depression, hypotension, ileus, urinary retention, dehydration and addiction. It is therefore desirable to minimize the requirement for opioid consumption after ARCR.

Liposomal bupivacaine injectable suspension and its potential use for PNB has been a recent topic of interest in an effort to provide patients with longer acting pain control after shoulder surgery compared to the use of bupivacaine or ropivacaine. Liposomal bupivacaine has a delayed onset of action so its practical use for PNB for ARCR requires the additive of bupivacaine to reduce pain during and immediately after surgery as a bridge to the onset of liposomal bupivacaine.

The purpose of this study is to determine if PNB utilizing liposomal bupivacaine combined with bupivacaine performs favorably to standard PNB with ropivacaine combined with dexamethasone. Primary and secondary outcomes will be assessed including worst pain reported postoperatively on a numeric rating scale(NRS), postoperative opioid consumption reported as oral morphine equivalent dosage(OMED) and the overall benefit of anesthesia (OBAS) as reported by the OBAS score.

The hypothesis of this study is that PNB with liposomal bupivacaine combined with bupivacaine will translate to lower postoperative daily NRS pain scores, decreased daily and total OMED consumed and lower OBAS scores compared to PNB with ropivacaine combined with dexamethasone over the first 8 days following surgery.