 Tools: The estimate of incidence of bacteremia but also the investigation of her microbiological explanation and the estimate of her repercussions for the patients it is used the Protocol of Bacteremia This protocol consist data as general elements, elements that concern the bacteremia as the samples, the micro-organisms, the resistance in the antibiotics, the mechanic ventilation, risk factors for growth of bacteremia, the empiric issuing of antibiotics but also the elements of outcomes of patients. 