Evaluating the Effects of Fascia Iliaca Blocks on Postoperative Opioid Use: A Retrospective Cohort Study.

Abstract

To evaluate differences in opioid use and length of stay (LOS) in patients treated with Fascia Iliaca (FI) blocks for a hip fracture compared to patients not receiving an FI block. Design: Retrospective Cohort Study. Nine University and Community Hospitals. Included were adults who underwent intramedullary nailing for hip fractures (OTA/AO 31A or OTA/AO 32) between January 2022 - October 2023 who either received a fascia iliaca block or did not prior to fixation. Primary outcomes of the study are Morphine milligram equivalents (MMEs) during admission and postoperative days (POD) 1-3; hospital length of stay (LOS) in days. Outcomes were compared between patients receiving FI blocks and those who did not. There were 610 patients (179 males, 431 females) included in the study. Patients receiving an FI block (N=273) were significantly older (83.1 ± 9.7 years vs. 81.0 ± 10.2 years, Range = 60-105 years, P = 0.023) and had lower American Society of Anesthesiologists (ASA) classifications (P = 0.001). Univariate analysis showed significantly less opioid use for the FI block group during overall admission (3.75 MMEs vs 11.25 MMEs, P = 0.046),but showed no differences from POD 1-3 (0 MMEs vs 0 MMEs, P = 0.187) or in LOS (5.08 days vs 4.84 days, P = 0.287). After adjusting for age and ASA classification, multivariate regression revealed no significant association between FI blocks and decreased opioid consumption on POD 1 (Partial Eta Squared (η2) = 0.002, P = 0.243), POD 1-3 (η2 = 0.002, P = 0.284), or during overall admission (η2 = 0.004, P = 0.122). Receiving a preoperative FI block did not decrease postoperative opioid consumption during hospitalization or LOS for older hip fracture patients when controlling for age and ASA classification. Level III Evidence.