The effects of early femoral nerve block intervention on preoperative pain management and incidence of postoperative delirium geriatric patients undergoing trochanteric femur fracture surgery: A randomized controlled trial

BACKGROUND: Hip fracture is a common clinical problem which causes severe pain in geriatric patients. However, severe pain following fracture may bring on mental disorders and delirium. A neuroinflammatory response with IL-6 and IL-8 has been shown to be associated with the pathophysiology of delirium. In this study, our primary hypothesis is that preoperative femoral nerve block (FNB) intervention in geriatric patients will more effectively attenuate pain following trochanteric femur fracture than the preoperative paracetamol application. Our secondary hypothesis is that interleukin levels (IL-6, IL-8) in cerebrospinal fluid (CSF) will be lower in the femoral nerve block group than the paracetamol group. Our tertiary hypothesis is that the incidence of postoperative delirium will be lower in the femoral nerve block group. METHODS: The patients over 65 years of age with ASA status II-IV and admitted to the Emergency Service for femur fracture were included in this study. Recommendations of the "delirium prevention table" were applied to all of the patients at arrival. In the first group, 15 mg/kg paracetamol was administered intravenously every eight hours. In the second group, femoral nerve blockage was performed, and a catheter was placed. Then, 0.5 mL/kg bupivacaine 0.25% was applied every eight hours. In both groups, pain scores four hours after interventions were recorded. All patients were operated within 48 hours under spinal anesthesia. During spinal anesthesia, 2 mL of CSF samples were taken from all patients for analysis of IL-6 and IL-8 cytokines, and pain scores during positioning were recorded. RESULTS: VAS scores four hours after the first preoperative pain treatment and during the positioning for regional anesthesia were significantly lower in the femoral nerve block group. IL-8 levels are significantly lower in the femoral nerve block group but not in IL-6 levels. The incidence of delirium was less in the femoral nerve block group, but the difference was not statistically significant. CONCLUSION: The femoral nerve block was more effective in preoperative pain management of trochanteric femur fracture and preventing pain during regional anesthesia application. The mean IL-8 level was lower in the femoral nerve block group when compared to the paracetamol group. There is no difference in the postoperative delirium incidence between groups.