Relationship between neutrophil/lymphocyte ratio and postoperative delirium in elderly patients with proximal femoral nail anti-rotation for intertrochanteric fractures

Objective: Delirium is a common postoperative complication in elderly patients with intertrochanteric femur fracture. This study aimed at analyzing risk factors for postoperative delirium (POD) in patients after proximal femoral nail anti-rotation (PFNA). Methods: From February 2017 to February 2021, we included elderly patients with intertrochanteric fractures who underwent PFNA. The predictive ability and cut-off value of neutrophil/lymphocyte ratio (NLR) for POD were evaluated using receiver operating characteristic (ROC) curve. Univariate and multivariate analyses were used to investigate the association between NLR and POD. Results: We enrolled 315 patients. The ROC curve suggested that NLR ≥ 4.85 was the optimal cut-off value for POD. The POD and non-POD groups differed significantly in age, diabetes, time from injury to operation, preoperative albumin level, neutrophil count, and NLR (P < 0.05). Logistic regression indicated that NLR ≥ 4.85 (odds ratio [OR] = 3.491; 95% confidence interval [CI]: 1.731-5.982; P < 0.001), old age (OR = 1.921; 95% CI: 1.267-4.125; P < 0.001), time from injury to operation ≥ 48 h (OR = 1.733; 95% CI: 1.212-3.542; P = 0.007), and preoperative albumin level ≤ 35 g/L (OR = 2.274; 95% CI: 1.662-4.846; P = 0.001) increased the risk of POD. Conclusion: Old age, time from injury to operation ≥ 48 h, preoperative albumin level ≤ 35 g/L, and NLR ≥ 4.85 were independent risk factors for POD. Thus, NLR may predict POD in elderly patients with intertrochanteric femur fractures after PFNA.