(926) Effect of Peripheral Nerve Blocks on Narcotic Utilization in Lung Transplants

Introduction: Lung transplantation is a complex surgical procedure associated with postoperative pain, frequently necessitating narcotic utilization. Peripheral nerve blocks with lidocaine are a promising modality for pain management in this population, but their impact on narcotic use remains unexplored.

Methods: This was a pre/post retrospective cohort study including adult patients who received a double lung transplant at University of Pittsburgh Medical Center Presbyterian Hospital from 2011 to 2023. In 2020, our transplant program initiated a pain management strategy including lidocaine nerve blocks peri-extubation. Patients before 2020 were the 'pre' group; those from 2020 onwards, the 'post' group. Each group was evaluated over four 24h periods corresponding to the 24h before time zero (baseline), and subsequent 24h periods till 72h. Time zero was defined as the first spontaneous breathing trial for the pre-group, and application of the nerve block for the post-group. Clinical outcomes were compared between the two groups, including comparisons of narcotic utilization, normalized to oral morphine equivalents (MME) and pain scores. The data were analyzed using a generalized linear mixed model using a truncated negative binomial distribution with a zero-inflated component.

Results: A total of 341 patients were included (188 pre- and 153 post, respectively). Opioid utilization at baseline was significantly higher in the post group compared to the pre group (228 [IQR: 53 – 452] vs. 145 [IQR: 45 – 360] MME, p< 0.05). The interaction between group and time was significant, p < 0.05. Plotting the interaction showed that after adjusting for baseline differences in opiate prescribing, patients with nerve block had a steeper decline than standard patients in opiate utilization over time. A higher proportion of opiate-free patients was seen in the post group (35% vs. 24%, p < 0.05), despite the higher initial doses and similar rates between groups at earlier days. There were no differences in pain scores between the groups from time zero through t72h.

Conclusions: In patients undergoing lung transplant, integrating lidocaine nerve blocks into postoperative pain management strategies was associated with reducing opioid utilization and achieving opiate-free status by day 4.