Physicians in Detroit have found that tight adherence to guidelines for managing community-acquired pneumonia (CAP) raises the risk of misdiagnosis and inappropriate use of antibiotics. Physicians in Detroit have found that tight adherence to guidelines for managing community-acquired pneumonia (CAP) - such as initiating antibiotics within four hours of registration in the emergency department (ED) - raises the risk of misdiagnosis and inappropriate use of antibiotics.

Dr. Mohamad G. Fakih and associates at St. John Hospital and Medical Center looked at outcomes of patients admitted to the ED with a diagnosis of CAP during six-month periods prior to and after publication of the guidelines. There were 199 patients treated between January and June, 2003, and 319 patients treated between January and June, 2005.

"We have seen almost a 60 per cent increase in the hospital admitting diagnosis of CAP compared to a < 25 per cent increase in the hospital discharge diagnosis of CAP," the research team reports in the June issue of Chest.

Results showed that the goal of starting antibiotic treatment within four hours increased from 54 to 66 per cent in the latter period (p = 0.007).

However, more patients in 2005 had a diagnosis of CAP without radiographic abnormalities (28.5 versus 20.6 per cent, p = 0.04). Of those misdiagnosed, only a minority were diagnosed with any type of infection, implying inappropriate antibiotic utilization.

Dr. Fakih's group observed no significant improvement over time in average hospital length of stay or in-hospital mortality. They therefore advocate a six-hour window between arrival at the ED and administration of antibiotics as a more feasible target.

"This target may provide more time for physicians to provide a better evaluation of the patient," Dr. Fakih and his colleagues write.