<prompt> A patient with severe neurological devastation after head trauma has a prolonged course in the intensive care unit. He has been mechanically ventilated for his entire hospital stay. Which of the following clinical findings is diagnostic of a ventilator-associated pneumonia?White blood cell count of greater than 12,000mLGreater than 1,000 colony-forming UmL of an organism on bronchoalveolar lavageGreater than 10,000 colony-forming UmL of an organism on bronchoalveolar lavagePurulent tracheal secretions  <response>: While findings such as fever, leukocytosis, purulent secretions, or a focal infiltrate on chest x-ray are suspicious for ventilator-associated pneumonia VAP, quantitative cultures are diagnostic. Samples may be obtained using bronchoscopy with bronchoalveolar lavage BAL. Greater than or equal to 10,000 colony-forming UmL of a single organism is diagnostic for VAP. Empiric antibiotics may be initiated after cultures are obtained based on clinical suspicion, but antibiotic coverage should be narrowed or stopped once an organism is identified to minimize development of resistant organisms 