Comparison of pre- and intra-operative analgesia of fascia Iliaca compartment block in reducing post-operative delirium of elderly patients following hip fractures: a retrospective study

BACKGROUND: Hip fractures significantly impact the physiological and psychological well-being of elderly patients. Post-operative delirium (POD) is a common complication after hip fractures in this population, severely affecting treatment outcomes and recovery. Effective pain management during the peri-operative period is crucial for reducing POD, yet the best analgesic approach remains debated. METHODS: A retrospective study (from January 2015 to December 2020) included 198 elderly hip fracture patients who received preoperative (PO-) or intraoperative (IO-) fascia iliaca compartment block (FICB) with 50 mL of 0.25% ropivacaine. Over the first 3 days (assessed every 24 h), cognitive function (Mini-Mental State Examination [MMSE]), pain intensity (Visual Analog Scale [VAS]), and systemic inflammatory mediators (CRP, IL-1, IL-6, TNF-α) were evaluated. Postoperative delirium (POD) incidence was daily assessed via the Confusion Assessment Method (CAM) for 72 h by a trained surgeon. Statistical analyses included intergroup comparisons of MMSE/VAS scores and inflammatory markers; cumulative POD incidence was analyzed using Kaplan-Meier curves. Normally distributed data were compared via independent-samples t-test, and categorical data (expressed as percentages) via chi-square (χ²) test. RESULTS: Patients were allocated to two groups: PO-FICB (n = 100) and IO-FICB (n = 98). Postoperatively, the PO-FICB group had significantly higher MMSE scores on days 1-3 (27.85 ± 1.923, 27.49 ± 2.807, 27.23 ± 1.698 vs. 25.80 ± 1.864, 25.73 ± 2.197, 22.57 ± 2.128; all P < 0.01) and lower levels of inflammatory mediators (CRP, IL-1, IL-6, TNF-α; all P < 0.05). VAS pain scores were lower in the PO-FICB group (1.58 ± 0.702, 2.26 ± 0.647, 2.40 ± 0.492 vs. 2.70 ± 0.659, 3.02 ± 0.853, 2.33 ± 0.620), with significant differences on days 1-2 (P < 0.0001) but not day 3 (P = 0.068). POD incidence was significantly lower in the PO-FICB group (5% [5/100]) than in the IO-FICB group (15.3% [15/98]; P = 0.0168). No severe complications or mortality were observed during 12-month follow-up. CONCLUSION: Compared with IO-FICB, PO-FICB may confer more targeted analgesia and is associated with a lower incidence of POD in elderly hip fracture patients. These associations might relate to PO-FICB's potential early effects of inhibiting inflammation and exerting putative neuroprotective-like actions, which are consistent with current multimodal perioperative management strategies and geriatric neuroprotective concepts. This finding provides preliminary support for considering PO-FICB as a viable option in perioperative regional anesthesia selection for this patient population.