Empiric therapy or empirical therapy is medical treatment or therapy based on experience and, more specifically, therapy begun on the basis of a clinical "educated guess" in the absence of complete or perfect information. Thus it is applied before the confirmation of a definitive medical diagnosis or without complete understanding of an etiology, whether the biological mechanism of pathogenesis or the therapeutic mechanism of action. The name shares the same stem with empirical evidence, involving an idea of practical experience. Empiric antimicrobial therapy is directed against an anticipated and likely cause of infectious disease. It is used when antimicrobials are given to a person before the specific bacterium or fungus causing an infection is known. When it becomes known, treatment that is used is called directed therapy. Fighting an infection sooner rather than later is important to minimize morbidity, risk, and complications for serious infections like sepsis and suspected bacterial meningitis. Empiric antimicrobial therapy Empiric antimicrobial therapy is typically broad-spectrum, in that it treats both a multitude of either Gram-positive and/or Gram-negative bacteria, diverse fungi or parasites respectively. When more information is known (as from a blood culture), treatment may be changed to a narrow-spectrum antimicrobial which more specifically targets the bacterium or fungus known to be causing disease. Empiric antimicrobial therapy is a fairly sophisticated process which includes considering data such as a person's age, immune status, comorbidities, likelihood for a certain microbial etiology and pre-test probability for antimicrobial resistance prior to therapy, risk of bad outcomes, and to name a few. Specimens are collected from affected body sites, preferably before antibiotics are given. For example, a person in an intensive care unit may develop a hospital-acquired pneumonia. There is a chance the causal bacteria, or its sensitivity to antibiotics, may be different to community-acquired pneumonia. Treatment is generally started empirically, on the basis of surveillance data about the local common bacterial causes. This first treatment, based on statistical information about former patients, and aimed at a large group of potentially involved microbes, is called empiric treatment. The advantage of indicating antibiotics empirically exists where a causative pathogen is likely albeit unknown and where diagnostic tests will not be influential to treatment. In this case, there may be little if any perceived benefit of using what may be costly and inconclusive tests that will only delay treatment of the same antibiotics. The empirical use of broad-spectrum antibiotics increases, by