Single Shot Liposomal Bupivicaine in Rotator Cuff Surgery

Outpatient surgery has become the gold standard for arthroscopic rotator cuff repair. Innovations in pain management with regional anesthesia and multimodal techniques have greatly contributed to this transition over the past several decades. Despite overall improvements, uncontrolled postoperative pain leads to prolonged ambulatory stays, increased patient dissatisfaction, unexpected admissions to the hospital or visits to the Emergency Room after surgery, and a greater incidence of complications. Furthermore, in the wake of the "opioid epidemic", concerns with narcotic consumption and addiction have become heightened with regulations and laws recently enacted making prescribing and managing postoperative pain ever more difficult.

Interscalene nerve blockade for shoulder procedures has become an increasingly common technique to provide perioperative pain control with good efficacy, low complication rates and reduced narcotic consumption. While the utilization of ultrasound to help administer the block has aided in the accuracy providing a more consistent analgesic effect, its overall short duration (12-24 hours) remains one of the major limitations of this technique. Modalities to prolong its effect have included use of indwelling catheters and the addition of perineural dexamethasone.

Recently, liposomal bupivacaine (LB) (Exparel) was approved for single shot interscalene administration by the FDA. This medication has been purported to provide up to 72 hours of extended release of bupivacaine via its multivesicular and honeycomb-like structure that predictably breaks down resulting in a slow and sustained release of the medication.9 Although numerous studies have been conducted and several meta-analyses performed looking at the overall efficacy of local injections of LB for operative procedures in an inpatient setting, no study to date has independently assessed its efficacy in the new perineural indication for outpatient shoulder surgery. Furthermore, no study to date has compared the use of LB to the use of LB with dexamethasone in a perineural indication to see if the duration of efficacy is further prolonged with the addition of dexamethasone. All existing literature is in regard to use of liposomal bupivacaine injected locally within the surgical site. This will be the first study to examine the perineural use of LB for outpatient shoulder surgery, and to determine if there is a prolonged decrease in pain and a decrease in narcotic consumption with the use of LB with dexamethasone when delivered as an interscalene block in an ambulatory setting.

Utilizing a prospective randomized controlled trial, this study seeks to evaluate if there is a difference in post-operative pain and narcotic use when LB is administered in an interscalene block during outpatient rotator cuff repair surgery. Furthermore, this study aims to determine if the addition of dexamethasone with LB results in a prolonged decrease in post-operative pain and an overall reduction in narcotic use.

Primary Aims & Objective

Aim 1a: To determine if the use of LB in an interscalene block decreases patient-reported post-operative visual analogue pain scale (VAS) in patients undergoing outpatient rotator cuff surgery

Hypothesis: There will be a decrease in the visual analogue pain scale for up to 72 hours post-operatively among participants who receive LB or LB plus dexamethasone, as compared to the control group (bupivacaine plus dexamethasone).

Objective: Utilizing a prospective randomized controlled trial, post-operative patient-reported VAS pain (on a scale of 1-10) will be collected 3 times per day (every 8 hours) for 5 post-operative days (PODs), corresponding to a total of 120 hours after surgery. For each 24-hour period (corresponding to each POD), the pain scores will be averaged and compared between the three treatment groups (control, LB, and LB plus dexamethasone) for each of the 5 PODs.

Aim 1b: To determine if the use of LB plus dexamethasone in an interscalene block decreases patient-reported post-operative VAS pain for a longer duration than the LB or the control group (bupivacaine plus dexamethasone) in patients undergoing outpatient rotator cuff surgery

Hypothesis: There will be a decrease in visual analogue pain scale for greater than 72 hours post-operatively among participants who receive LB plus dexamethasone, as compared to the LB and the control group (bupivacaine plus dexamethasone).

Objective: Utilizing a prospective randomized controlled trial, post-operative patient-reported visual analogue pain scale (on a scale of 1-10) will be collected 3 times per day (every 8 hours) for 5 post-operative days (PODs), corresponding to a total of 120 hours after surgery. For each 24-hour period (corresponding to each POD), the pain scores will be averaged and compared between the three treatment groups (control, LB, and LB plus dexamethasone) for each of the 5 PODs.

Secondary Aims & Objectives

Aim 2a: To determine if there is a difference in time at which post-operative narcotics are first used among three groups receiving different interscalene blocks (LB plus dexamethasone, LB, and control) in patients undergoing outpatient rotator cuff surgery.

Hypothesis: Narcotic use will begin at a later time among those receiving LB plus dexamethasone, as compared to the LB and the control group (bupivacaine plus dexamethasone).

Objective: Utilizing a prospective randomized controlled trial, narcotic use will be collected at 8-hour increments for a total of 5 post-operative days (PODs), corresponding to a period of 120 hours post-surgery. The 8-hour time period during which a participant first begins using a narcotic will be recorded and compared between three treatment groups (control, LB, and LB plus dexamethasone).

Aim 2b: To determine if there is a difference in patient-reported post-operative narcotic use (measured in morphine equivalents) among three groups receiving different interscalene blocks (LB plus dexamethasone, LB, and control) in patients undergoing outpatient rotator cuff surgery.

Hypothesis: There will be a decrease in cumulative narcotic use (measured in morphine equivalents) among participants who receive LB plus dexamethasone, as compared to the LB and the control group (bupivacaine plus dexamethasone).

Objective: Utilizing a prospective randomized controlled trial, post-operative patient-reported narcotic use (measured by the number of tablets ingested and converted to morphine equivalents) will be collected 3 times per day at 8-hour increments for a total of 5 post-operative days (PODs), corresponding to a total of 120 hours after surgery. For each 24-hour period (corresponding to each POD), narcotic use will be tabulated and compared between three treatment groups (control, LB, and LB plus dexamethasone). Furthermore, cumulative narcotic use during the 5-day (120 hour) study period will be calculated and compared between three treatment groups (control, LB, and LB plus dexamethasone).