Liposomal Bupivacaine Versus Bupivacaine for Intercostal Nerve Blocks in Thoracic Surgery: A Retrospective Analysis

Abstract

Background: Liposomal bupivacaine (LipoB), delivered via intercostal nerve blocks (ICNBs), is increasingly being used for postoperative pain control in thoracic surgery patients, but there is limited data on its effectiveness when compared to standard bupivacaine. Objective: We sought to compare postoperative opioid use, pain control, and length of stay (LOS) in patients undergoing thoracic surgery with LipoB ICNBs vs patients undergoing thoracic surgery with ICNBs using standard bupivacaine. Study Design: A retrospective analysis. Setting: Research took place in a tertiary academic medical center. Methods: A transition in the standard of care from standard bupivacaine to LipoB for ICNBs in March of 2014 allowed us to compare 2 cohorts: patients who received bupivacaine ICNBs from January 2013 through February of 2014 and patients who received LipoB ICNBs from March 2015 through November 2017. We included patients who underwent thoracic surgery for lung cancer using robotic-assisted thoracic surgery (RATS), video-assisted thoracic surgery (VATS), or traditional open thoracotomy, and documentation of ICNB in the operative note. We collected data on pain scores (Visual Analog Scale [VAS]) and opioid consumption (converted to oral morphine equivalents [OMEs]) intraoperatively, on postoperative day (POD) 0, POD 1, POD 2, and POD 3. We also analyzed data on length of stay [LOS]. A primary analysis was performed on the effects of LipoB vs bupivacaine across all surgery types on opioid consumption, pain scores, and LOS with a secondary analysis on the same endpoints per individual surgery type. Results: A total of 129 patients were included from the predefined study periods (n = 62 LipoB and n = 67 standard bupivacaine). Across all surgery types, LipoB decreased opioid utilization vs standard bupivacaine (P < .01). Post-hoc testing revealed that this difference existed intraoperatively (55 ± 5 vs 69 ± 4 mg OME, P = .03) and on POD 0 (44 ± 6 vs 68 ± 6 mg OME, P < .01). Surgical subtype analysis revealed that this difference was mostly driven by lower opioid consumption in patients undergoing RATS. When compared across all surgery types, LipoB vs bupivacaine did not affect postoperative pain scores. However, subgroup analysis showed that pain scores were lower in the LipoB vs standard bupivacaine group undergoing VATS on POD 0, 1, and 2. The LOS across all thoracic surgery types was lower in the LipoB group when compared to the standard bupivacaine group (median, 4 days [IQR 2.0-6.0] vs median, 5 days [IQR 3.0-8.0], P < .01). Subgroup analysis showed that the LOS in patients undergoing VATS with LipoB ICNBs was shorter compared to patients receiving bupivacaine ICNBs. Limitations: The retrospective nature of this study makes it prone to several types of bias. Conclusion: ICNBs with LipoB for thoracic surgery leads to lower opioid consumption and shorter LOS when compared to ICNBs with standard bupivacaine. The benefit of LipoB over standard bupivacaine for ICNBs appears especially relevant in VATS or RATS procedures. Key words: Intercostal nerve block, liposomal bupivacaine, RATS, regional anesthesia, roboticassisted thoracoscopic surgery, thoracotomy, VATS, video-assisted thoracoscopic surgery