Differential diagnosis of fever and pulmonary densities in mechanically ventilated patients.

Sepsis continues to represent a major threat to the recovery of mechanically ventilated patients and a serious challenge to physicians in charge of their care. Diagnosis of pneumonia is made difficult by numerous infectious and noninfectious conditions that may present in a clinically similar fashion. Clinical criteria are insensitive in identifying extrapulmonary sources of fever. Furthermore, several pathologic conditions may coexist in a single patient, making correct diagnosis and treatment even more difficult. A thorough understanding of the various causes of fever and pulmonary densities, other than pneumonia, is necessary to avoid misdiagnosis and inappropriate treatment. This understanding then allows a systematic approach to diagnosis using the most appropriate tests.