[The value of criteria for pneumonia in the diagnosis of a ventilated pneumonia].

Reliable diagnosis of pneumonia in ventilated patients is frequently difficult, since there is no single specific criterion. In the present study, the following diagnostic criteria for pneumonia were checked in 25 ventilated patients: 1. temperature over 38.5 degrees C, 2. leukocytosis over 12,000/mm3, infiltration in the x-ray, 4. positive auscultatory findings, 5. purulent tracheal secretion (TS), 6. positive bacteriological findings (TS). Diagnosis of bacterial pneumonia was assumed if in the bronchoalveolar lavage (BAL) the concentration of a plausible causative organism was greater than or equal to 10(4)/ml and the "Bacterial Index" (BI) was greater than or equal to 6 (16). 15 patients fulfilled more than four criteria for pneumonia. In all patients the concentration of bacteria in the BAL was greater than or equal to 10(4)/ml (median 10(6)/ml, BI: 10). 10 patients fulfilled less than or equal to 4 criteria of pneumonia. In three of the patients, BAL was sterile, in four cases organisms less than 10(4) were isolated; none of these patients received antibiotics and diagnosis of pneumonia was not confirmed in the further course of illness. In three patients, bacteria greater than or equal to 10(4)/ml were isolated (BI 9, 10, 13); they improved under adequate antibiotic therapy. We conclude from these results that "as a rule" more than four of the criteria of pneumonia specified above should be present for diagnosis of pneumonia in ventilated patients in a surgical intensive-care ward. If there is any doubt, BAL should be performed to confirm the diagnosis.