Aggregometry in Elderlies With Hip Fracture and Receiving Clopidogrel

In elderly patients, hip fracture should be surgically treated within 48 hours from admission, since its deferral worsens the mortality. However, sometimes patients are affected by cardiovascular or cerebral comorbidities, deeming necessary the use of antiplatelets and/or anticoagulant therapies. Clopidogrel is a second-generation thienopyridine antiplatelet drug which exerts its effect by the inhibition of the platelet's purinergic receptor P2Y12 preventing adenosine diphosphate (ADP) from stimulating it. Guidelines recommend to withhold clopidogrel for 5 days before the possibility to perform neuraxial anesthesia, which is frequently the optimal perioperative management of a fragile patient. It should be mentioned however that around 30% of patients are resistant to clopidogrel and they show a normal platelet reactivity despite the antiplatelet therapy. Therefore, in principle, these patients do not require to defer surgery. We have therefore hypothesized that some patients taking clopidogrel might anticipate surgery before 5 days and within 48 hours, following a protocol based on the assessment of coagulation and platelet aggregation through thromboelastography (TEG) in combination with an ADP Platelet Mapping assay kit. After hospital admission for femur fracture, eligible patients would be evaluated by the anesthesiologist and the orthopedic physicians for anesthesia and surgery. Immediately a sample of blood should be collected for TEG with ADP Platelet Mapping test. If both MA-ADP and platelets aggregation (%) will be within normal values, the patient could be considered as candidate for immediate surgery (within 48 hours) with neuraxial anesthesia and ultrasound-guided antalgic femoral nerve block. If MA-ADP and/or platelets aggregation (%) are lower, risk for mortality should be assessed. If the patient would be considered at high risk for mortality, he/she would undergo to general anesthesia and peripheral antalgic block to not postpone surgery. Otherwise