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

OBJECTIVES: To evaluate differences in opioid use and length of stay (LOS) in patients treated with fascia iliaca (FI) blocks for a hip fracture compared with patients not receiving an FI block. DESIGN: Retrospective cohort study. SETTING: Nine University and Community Hospitals. PATIENT SELECTION CRITERIA: Included were adults who underwent intramedullary nailing for hip fractures (OTA/AO 31A or OTA/AO 32) between January 2022 and October 2023 who either received a FI block or did not before fixation. MAIN OUTCOME MEASURES: Primary outcomes of the study are Morphine milligram equivalents (MMEs) during admission and postoperative days (POD) 1-3; hospital LOS in days. Outcomes were compared between patients receiving FI blocks and those who did not. RESULTS: There were 610 patients (179 men, 431 women) 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 (η 2 ) = 0.002, P = 0.243], POD 1-3 (η 2 = 0.002, P = 0.284), or during overall admission (η 2 = 0.004, P = 0.122). CONCLUSIONS: 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 OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.