Exparel vs. Marcaine ESP Block for Post-cardiac Surgical Pain

Randomized Control Trial to Assess the Efficacy of Preoperative Erector Spinae Blocks on Cardiac Surgery Postoperative Outcomes

The goal of this pilot study is to describe and compare Ultrasound-Guided Erector Spinae Plane (ESP) Blocks using Exparel® (bupivacaine liposome injectable suspension) to Marcaine® (bupivacaine hydrochloride) for pain management and outcomes after cardiac surgeries.

Postoperative pain is a major concern for patients after cardiovascular surgery.

With an increasing emphasis on improving perioperative care arising from evidence-based protocols such as Enhanced Recovery After Surgery (ERAS), reducing postoperative pain not only increases patient satisfaction, but also decreases postoperative complications and improves outcomes. Reduced postoperative pain also decreases rates of pneumonia and time on mechanical ventilation, in the ICU, or in the hospital. Importantly, decreasing postoperative pain can also reduce high dose opioid usage, the established method of managing postoperative pain, thereby decreasing rates of nausea/vomiting, intubation time, and mortality. Methods of reducing postoperative pain, such as neuraxial anesthesia and deep plexus blocks, are associated with an increased risk of epidural hematoma; an alternate solution, therefore, is using fascial plane blocks.

Since 2018, our institution is one of very few that uses pre-operative fascial plane blocks for cardiac surgery patients, implementing bilateral plane blocks for the sternotomy approach and unilateral plane blocks for the right mini-thoracotomy approach. Results from these blocks have been quite favorable but not yet validated.

A study in which subjects are randomized to not receive an ESP block preoperatively would raise concerns regarding equipoise. Therefore, this study is designed to better understand the overall effects of these blocks by comparing FDA approved medications, Exparel (current practice at RWJUH) and Marcaine. Marcaine (0.25% bupivacaine HCl) has an onset of action on the order of seconds and generally within one minute from the time of injection, and an effect duration of roughly seven hours. Exparel is a commercially available extended-release formulation of liposomal bupivacaine, which extends the effect duration to an upward of 72 hours from the time of injection with similarly immediate onset of action. Several studies have compared local injections of Marcaine (plain bupivacaine) with Exparel (liposomal bupivacaine) in the setting of inguinal hernia repair, knee arthroplasty, breast augmentation, and hemorrhoidectomy, with results favoring the use of liposomal bupivacaine based on improvements in subjective pain at the initial postoperative pain assessment.(6) Clinical trials are currently underway, investigating the effect of liposomal bupivacaine for local anesthesia and compared with epidural anesthesia in thoracoscopic surgery. In a recent clinical trial published in the Journal of the American Medical Association (JAMA), patients undergoing cardiothoracic or vascular surgery subjected to truncal incisions did not demonstrate a significant benefit with respect to pain control or adjunctive opioid usage when treated with liposomal bupivacaine over plain bupivacaine via local injection. Still, a gap in the literature exists with respect to the use of liposomal bupivacaine versus plain bupivacaine for erector spinae plane block in the setting of sternotomy. The aim of this prospective study is to determine the impact of preoperative fascial plane blocks with Exparel compared to Marcaine on outcomes following cardiac procedures.

Inclusion Criteria:

• Adults (18 years-no upper age limit)
• Scheduled for mini thoracotomy (i.e. valve repair) or open sternotomy (i.e. bypass graft) at single academic medical center (in and out-patients).

Exclusion Criteria:

Patients will be excluded if they:

• Are currently on pain medication or pain regimen for chronic pain condition
• Convert to sternotomy (for thoracotomies)
• Require, upon intraoperative discovery and surgeon's decision, the need for an unplanned secondary procedure other than the originally scheduled index operation
• Undergo emergent surgery
• Are non-English speaking (The majority of the PI's patient population speak English. As a pilot study the investigators cannot afford to enroll non-English speaking subjects due to time, personnel, and financial constraints.)
• Mechanical circulatory support (MCS)
• Vasoactive medications
• Intubated
• Active infection
• Patients otherwise deemed ineligible for ESP block by the investigators due to safety concerns.