[Predictive value of history and physical examination for the diagnosis of community-acquired pneumonia in adults].

BACKGROUND

Community-acquired pneumonia in adults is a serious health problem in the ambulatory care setting.

AIM: To define clinical variables associated with the presence of pneumonia in adult patients presenting with fever or respiratory symptoms to the emergency department.

MATERIAL AND

METHODS

Prospective study carried out in the emergency department from the Catholic University Hospital in Santiago, Chile. Three hundred twenty-five patients (53+/-22 years) presenting fever or acute respiratory symptoms were included. After obtaining a clinical history and physical examination, the physician established a tentative diagnosis. Subsequently, a definitive diagnosis was made with the chest X rays.

RESULTS

Thirty-four percent of the patients had pneumonia. The clinical diagnosis of pneumonia before X-ray examination was variable among emergency physicians (positive likelihood ratio: 1.5-4.8) and showed only moderate sensitivity (79%) and specificity (66%). The clinical variables significantly associated with the presence of pneumonia were: advanced age (over 75 years), cardiovascular disease, fever, chills, sputum production, orthopnea, altered mental status, cyanosis, dullness on percussion, bronchial breath sounds, crackles, any abnormal vital sign (heart rate>or=100 beats/min, respiratory rate>or=20 breaths/min or temperature>or=38 degrees C) and oxygen saturation below 90% breathing air.

CONCLUSIONS

Clinical judgment prior to observation of chest X rays had moderate sensitivity and specificity for the diagnosis of pneumonia. There were no individual clinical findings, or combination of findings, that could confirm or exclude the diagnosis of pneumonia for a patient suspected of having this illness.