After a first pro-inflammatory phase, a second compensatory phase called Compensatory Anti-Inflammatory Response Syndrome (CARS) takes place quickly. Patients then show signs of immunosuppression and profound alterations in immune functions. It is during this phase that the vast majority of deaths occur, far from the onset of the shock, which is related to the inability of the immune system to eliminate the initial infectious agent and / or a greater susceptibility Important to develop secondary infections (nosocomial infection, latent virus reactivation ...).