Anticoagulants and fracture morphology have a significant influence on total blood loss after proximal femur fractures

INTRODUCTION: Blood loss after proximal femoral fractures is an important risk factor for postoperative outcome and recovery. The purpose of our study was to investigate the total blood loss depending on fracture type and additional risks, such as anticoagulant use, to be able to recognize vulnerable patients depending on planned surgery and underlying comorbidities. MATERIALS AND METHODS: A retrospective single center study including 1478 patients treated operatively for a proximal femoral fracture between January 2016 and June 2020 at a level I trauma center. Patient data, surgical procedure, time to surgery, complications and mortality were assessed. Lab data including hemoglobin and transfusion rates were collected. The Mercuriali formula was implemented to calculate total blood loss. Linear regression was performed to identify influencing factors. RESULTS: One thousand four hundred seventy-eight mainly female patients were included in the study (mean age: 79.8 years) comprising 667 femoral neck fractures, 704 pertrochanteric- and 107 subtrochanteric fractures. Nearly 50% of the cohort were on anticoagulants or anti- platelet therapy. At time of admission average hemoglobin was 12.1 g/l. Linear regression proved fracture morphology, age, BMI, in-house mortality and anticoagulant use to have crucial influence on postoperative blood loss. Femoral neck fractures had a blood loss of 1227.5 ml (SD 740.4 ml), pertrochanteric fractures lost 1,474.2 ml (SD 830 ml) and subtrochanteric femoral fractures lost 1902.2 ml (SD 1,058 ml). CONCLUSIONS: Hidden blood loss is underestimated. Anticoagulant use, fracture type, gender and BMI influence the total blood loss. Hemoglobin levels should be monitored closely. Within 48 h there was no increased mortality, so adequate time should be given to reduce anticoagulant levels and safely perform surgery.