BACKGROUND
Hip fractures are one of the most common fractures treated by orthopedic surgeons. With increasing life expectancy, its incidence is expected to rise in the next years. El-derly patients are usually osteoporotic, with multiple comorbidities, and are therefore at high risk of hip fractures and postoperative complications.

Blood loss is a major issue in hip fractures and transfusion of blood products is frequently required. Although blood transfusion may be a life-saving intervention, it may increase morbidity, especially bacterial infections, possibly mortality, with substantial costs involved. 

METHODS
We retrospectively analyzed 134 femoral neck fracture patients, admitted from January and December of 2016, who underwent urgent primary surgery in a tertiary teaching hospital. High kinetic trauma, under 18 years old and pregnant patients were excluded. The primary outcome was administration of blood products. Statistical analysis was performed using SPSS software. Significant results were considered when p<0.05.

RESULTS
The average age of patients submitted to hip fracture surgery in this study was 83.46 years (ranging from 42 to 103 years), 72.4% were female and 26.6% were male. Re-garding previous degree of autonomy in daily activity, 15.7% were considered depend-ent, 39.6% partially dependent and 43.3% independent. 17.3% of the patients lived in a nursing home and 11.2% had been hospitalized in the previous 3 months. As per comorbidities, 25.2% suffered from dementia, 25.9% had heart failure, 9.7% had chron-ic obstructive pulmonary disease, 17.2% had diabetes mellitus type 2 and the incidence of renal disease was 19.4%. 
Blood products were administered in 23.1% of our patients either during surgery or in the postoperative period. Blood transfusion need was associated with female gender (OR 6.4, p=0.006), low preoperative hemoglobin (Hb), intraoperative blood loss, mini-mum heart rate during surgery, and duration of the procedure (p<0.05).

CONCLUSION
Among the variables associated with blood transfusion requirement, the only modifiable ones were preoperative Hb, intraoperative blood loss and duration of procedure. In this study 58.9% of the patients had anemia (preoperative Hb<12g/dL). Previous studies have also identified low preoperative Hb as a risk factor for transfusion and suggest that only values under 12g/dL should require crossmatching. Others point that intraoperative blood loss has been associated with delay of surgery, type of fracture and fixing meth-od. Recently the role of intraoperative tranexamic acid in hip fractures is being dis-cussed. More studies are needed to better understand risk factors for blood transfusion in order to minimize associated morbidity and mortality. 

REFERENCES
1. Dennison E, Mohamed MA, Cooper C. Epidemiology of osteoporosis.
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2. Desai, SJ, MD. Et al. Factors affecting transfusion requirement after hip fracture: Can we reduce the need for blood?. J can chir, Oct 2014. Vol. 57, Nº 5.

08 / Hip fracture: blood loss in a vulnerable population