Admixture of Liposomal Bupivacaine and Bupivacaine Hydrochloride for Peripheral Nerve Blocks in Adolescents Undergoing Orthopedic Surgery: An Observational Cohort Study

<b>Background/Objectives</b>: In 2021, the Food and Drug Administration approved liposomal bupivacaine injectable suspension for single-dose infiltration in patients ≥ 6 years of age. Liposomal bupivacaine and bupivacaine hydrochloride admixtures may also be administered off-label for pediatric regional anesthesia including peripheral nerve blocks (PNBs). This single-injection, long-acting technique is not well described in pediatrics but may have benefits over traditional continuous catheter-based systems. The purpose of this investigation was to examine an adolescent cohort who received liposomal bupivacaine/bupivacaine hydrochloride PNBs for orthopedic surgery. <b>Methods</b>: Patient, surgical, anesthetic, block characteristics, and post-anesthesia care unit (PACU) outcomes were retrospectively reviewed from February 2020 to June 2024. From February to December 2022, a short follow-up survey was conducted to assess post-discharge patient-reported outcomes. <b>Results</b>: There were 524 liposomal bupivacaine/bupivacaine hydrochloride PNBs (106 upper-extremity and 418 lower-extremity) performed in 374 patients with a mean (standard deviation, range) age of 16 (1.2, 11-17) years. Two unilateral PNBs were performed in 150 (40%) patients to ensure an adequate sensory neural blockade. The interscalene (<i>n</i> = 81, 15%) and adductor canal (<i>n</i> = 140, 27%) blocks were the most common upper- and lower-extremity PNBs, respectively. Intraoperatively, the majority of the cohort (<i>n</i> = 258, 69%) underwent monitored anesthesia care (MAC). No patient required conversion from MAC to general anesthesia due to pain. In PACU, 288 (77%) patients reported no pain. Mild and moderate pain were reported by 56 (15%) and 30 (8%) patients, respectively. No patients developed local anesthetic toxicity. The survey results (<i>n</i> = 66) indicate that the majority of patients (96%) were satisfied with block analgesia postoperatively. <b>Conclusion</b>: Liposomal bupivacaine/bupivacaine hydrochloride PNBs were used successfully in adolescents undergoing a variety of orthopedic surgeries.