Study of Platelet Activation in Septic Shock Patients

Inclusion Criteria: EXPERIMENTAL GROUP * Patient who possibly gave an oral agreement to inclusion and may sign a consent once out of intensive care * Patients hospitalized in general intensive care * Patient hospitalized for less than 72 hours * Patient suffering from severe sepsis, whatever their origin, with hypotension (PAs \<90mmHg) despite adequate fluid resuscitation and vasoactive requiring the use of amines, with hypoperfusion and / or at least one organ dysfunction ( septic shock) * Patient with a Sequential Organ Failure Assessment (SOFA) score\> 8 (or\> 2 in an organ) in the first 24 hours * Patient enjoying a social security scheme or equivalent CONTROL GROUP * Signed informed consent * Patient seen anesthesia consultation for orthopedic knee prosthesis of laying or hip with a negative balance infectious * Patient enjoying a social security scheme or equivalent Exclusion Criteria: EXPERIMENTAL GROUP * Patient on safeguarding justice, guardianship * Patient suffering from a haematological malignancy (leukemia, lymphoma ...) * Patient suffering from thrombocytopenia or constitutional thrombopathy * Pregnant CONTROL GROUP * Patient on safeguarding justice, guardianship * Patient with infectious positive balance (dental, urinary tract) prior to surgery * Patient suffering from a haematological malignancy (leukemia, lymphoma ...) * Patient suffering from thrombocytopenia or constitutional thrombopathy * Pregnant