[Initial hemoglobin value as a predictor of allogeneic blood transfusion in hip fracture]

Hip fracture is a cause of major morbidity and mortality and is often associated with high blood transfusion rate, non-complication-free therapy. The objective of the study is to evaluate the factors dependent and independent of the transfusional act, as well as to elaborate an algorithm that allows us to make a decision making based on a statistical model rationalizing the use of blood.

Prospective study on 100 patients older than 65 years intervened for hip fracture consecutively. We analyzed demographic data, drug taking, comorbidity, pre- and postoperative analytics, type of fracture and those related to surgery valuing uni- and bivariate determinants of the Transfusional Act to control the possible bias of confusion.

Following the application of the bivariate logistic regression model only the HB at the admission (p = 0.04, or = 0.451) and the type of fracture (p = 0.003, or = 5.479) were considered associated with the transfusion act. The value of initial HB generates a ROC curve with an area under the curve of 0.848, acceptable to assess the probability of transfusion. An initial HB value lower of 12.15 g/dl will predict the transfusion with a sensitivity of 80% and a specificity of 85%.

The presence of preoperative anemia and extracapsular hip fractures generate a high risk of transfusion need, while it is unlikely in intracapsular fractures without anemia at admission. In our series there is an analytical value that predicts satisfactorily 80% of blood transfusions.