Platelet Reactivity in Septic Shock

Blood samples were anticoagulated with 0.129 mmol/L of sodium citrate and then centrifugated for 10 min at 200 rpm; platelets aggregation was assessed with an AggRAM Advanced Modular System light transmittance aggregometer (Helena Laboratories, Beaumont, Texas, USA). Low-molecular-weight heparin (LMWH) was given at least 8 hours before any blood aggregation sample. Agonist used to initiate aggregation test were: -Adenosine diphosphate (ADP) to assess P2Y12-dependent platelet aggregation; (20 ng) - Arachidonic acid (AA) to assess cyclooxygenase-dependent platelet Adenosine diphosphate aggregation (1 mcg) - thrombin receptor-activating peptide-6 (TRAP-6) to assess protease-activated receptor 1-dependent platelet aggregation. Max aggregation reached (Aggmax), the slope of the curve (slope) and the latency time (lat) were analyzed for each agonist.