Risk Factors Analysis and Nomogram Construction for Blood Transfusion in Elderly Patients with Femoral Neck Fractures Undergoing Hemiarthroplasty

Introduction: Elderly patients with femoral neck fractures (FNFs) undergoing hemiarthroplasty usually have poor physical condition. The main aim of this study was to identify risk factors for blood transfusion in these patients and construct a nomogram to intuitively predict the requirement of transfusion. The secondary purpose was to examine the relationship between blood transfusion and complications within 30 days post-operatively. Our hypothesis was that chronic kidney disease (CKD) and hypoalbuminemia may increase the requirement of transfusion.

Methods: Data of 414 elderly patients undergoing hemiarthroplasty for FNFs were retrospectively collected. Univariate and multiple regression analysis were performed to identify independent risk factors for blood transfusion, which were used to construct a nomogram subsequently. The discrimination and calibration of the nomogram model were assessed with concordance index (C-index), the area under receiver operating characteristic curve (AUC), and calibration curve. Furthermore, the complications of blood transfusion within 30 days post-operatively were also analyzed.

Results: Out of 414 patients, 127 (30.7%) received a blood transfusion. Independent risk factors for blood transfusion included CKD, hypoalbuminemia, pre-operative anaemia, general anaesthesia, higher American Society of Anesthesiologists score, more intraoperative blood loss, and longer surgical time. Increased hidden blood loss, deep vein thrombosis, superficial wound infection, and prolonged hospital stays were more common in transfused patients. The C-index of the nomogram model was 0.848 (95% CI = 0.811-0.885), and the AUC value was 0.859. The calibration curve showed a good consistency between the actual transfusion and the predicted probability.

Discussion: We observed a transfusion rate of 30.7% in elderly FNF patients undergoing hemiarthroplasty. CKD and hypoalbuminemia were firstly identified as independent risk for blood transfusion. In addition, blood transfusion can increase the occurrence of early post-operative complications.

Conclusion: Targeted pre-operative intervention, such as optimizing CKD and correcting hypoalbuminemia is essential and highly regarded.