Objective: To study the predictive value of clinical chest findings for bronchial airflow limitation in patients with respiratory tract infection.
Design: Associations were analysed between FEV1 (forced expiratory volume in one second) in % of predicted and physical chest findings.
Setting: The Municipal Emergency Clinic in Tromsø, Norway.
Participants: 398 adult patients with respiratory tract infection and 40 general practitioners.
Outcome measures: Mean FEV1% predicted and frequency of FEV1 < 80% predicted according to chest findings. Regression coefficients of the findings with FEV % predicted as outcome variable.
Results: Mean FEV1% predicted was 87 (range 25-129). Pathological chest findings were recorded in 127 patients (32%) and in 22 of the 24 patients (92%) with FEV1% predicted less than 60. The 78 patients with wheezes had a mean FEV1% predicted of 74 (range 29-120), significantly lower than those without wheezes (p < 0.0001), and 63% had FEV1% predicted less than 80. Prolonged expiration or strenuous respiration was recorded in 49 patients. The 29 patients with wheezes in this subgroup had a significantly lower mean FEV1% predicted, 65, than the 20 patients without wheezes (p < 0.005). By multiple regression wheezes and strenuous respiration were the most significant predictors of FEV1% predicted, together with patients' statement of very annoying dyspnoea.
Conclusion: When predicting the degree of bronchial obstruction in a patient with respiratory infection, the doctor may take into account wheezes heard by auscultation, an impression of strenuous respiration, and the patient's statement about severe dyspnoea.