Evan Shuler, PharmD,
Emergency Medicine Pharmacy Specialist
University Hospitals Cleveland Medical Center
Toledo, Ohio
Disclosure information not submitted.
Brian Lauer, PharmD, BCCCP
Clinical Pharmacy Specialist, Trauma Surgical Intensive Care Unit
University Hospitals Cleveland Medical Center, United States
Disclosure information not submitted.
Basanta Mohapatra, MD
Anesthesiologist
University Hospitals Cleveland Medical Center, United States
Disclosure information not submitted.
Title: Effectiveness of Serratus Anterior Plane Blocks on Postoperative Pain Control in Cardiac Surgery
Introduction: Cardiac surgery with median sternotomy is associated with significant post-operative pain. To improve pain control, ultrasound-guided serratus anterior plane (SAP) chest wall blocks have been utilized in surgical patients, though there is limited data involving these blocks in cardiac surgery. At University Hospitals Cleveland Medical Center (UHCMC), SAP blocks with ropivacaine have been utilized in cardiac surgery patients since 2019, with single or continuous SAP blocks used on a case-by-case basis. The purpose of this study is to evaluate the impact of ropivacaine-based SAP blocks on pain control following cardiac surgery.
Methods: This IRB-approved, single-center, retrospective chart review included patients 18 years and older who had cardiac surgery at UHCMC between July 1, 2019 and June 30, 2020. The primary endpoint was post-operative opioid use between patients receiving a continuous SAP block, single SAP block, and no SAP block, converted into morphine milligram equivalents (MME). Secondary endpoints included post-operative pain scores using a 0-10 Numeric Rating Scale (NRS) and intensive care unit (ICU) length of stay. Exclusion criteria included a previous history of cardiac surgery, emergent cardiac surgery, history of chronic opioid or alcohol use disorder, requirement of mechanical cardiac support devices following cardiac surgery, or mechanical ventilation for greater than 48 hours.
Results: Of the 350 patients screened for inclusion, 200 were included in the final analysis. Baseline patient characteristics were similar between the groups, aside from a significantly longer time spent on mechanical ventilation in patients with no SAP block. For the primary endpoint, median use of opioid analgesics was similar between the continuous, single, and no SAP block groups at 72 hours (84, 105, and 86 MME; p=0.22). Median average NRS pain score in the 72 hours following ICU admission was similar between groups (4.6, 4.7, and 4.1; p=0.49). Despite this, ICU length of stay was shortest in the continuous SAP block group (32, 42, and 64 hours; p= < 0.01).
Conclusions: Use of ropivacaine-based SAP blocks did not improve pain control or decrease opioid use following cardiac surgery, though was associated with reduced ICU length of stay. Prospective data is needed to confirm or reject these findings.