Are routine blood cultures effective in the evaluation of patients clinically diagnosed to have nosocomial pneumonia?

Blood cultures are a routine part of the evaluation of patients with clinically diagnosed nosocomial pneumonia; however, their utility has not been proven. We performed a retrospective chart review of 77 consecutive trauma patients diagnosed clinically to have nosocomial pneumonia at our level 1 trauma intensive care unit. Routine blood cultures did not alter the therapy of patients clinically diagnosed to have nosocomial pneumonia. We found the incidence of gram negative pneumonia was 71.4 per cent (55/77 patients) and gram positive pneumonia was 40.3 per cent (31/77 patients). Routine blood cultures taken at the time of diagnosis of nosocomial pneumonia fail to alter therapy.