D142. The Impact of Tumescent Local Anesthesia on Postoperative Pain and Opioid use in DIEP Flap Breast Reconstruction

PURPOSE: In efforts to enhance postoperative pain control and reduce the risk of opioid misuse, our team has implemented the use of tumescent local anesthesia with bupivacaine(TLA) in DIEP flap breast reconstruction(BR) for the breast and abdominal donor-site. We aimed to evaluate the impact of this technique on postoperative pain and opioid use in this patient population. METHODS: A single institution retrospective study on patients who underwent DIEP flap BR from 2015-2023 was conducted. A random sample, categorized by TLA use, is presented as preliminary data. T-tests and Fisher's Exact tests assessed baseline differences. Multivariable logistic and linear regression models evaluated differences between groups. RESULTS: Sixty-eight patients were included, with 38 managed with TLA. Patients treated with TLA had an average opioid prescribed at discharge of 87.2MME(morphine milligram equivalent) lower than the control group (95%CI[-149.4,-23.1];p=0.007). Patients age 65 years or older, who were treated with TLA, had an average inpatient opioid use of 41.4MME lower than patients younger than 40 years old (95%CI[-79.4, -3.5];p=0.034). CONCLUSION: The use of TLA during DIEP flap BR is significantly associated with a lower amount of opioids both inpatient and after discharge, particularly in patients older than 65 years old. Further research is necessary to characterize the opioid use and renewal rates after discharge. Using a multimodal strategy for pain reduction, our study proposes a strategy to potentially decrease opioid misuse.