Blood gas analysis and chest x-ray findings in infants and preschool children with acute airway obstruction.

The importance of SaO2 in the assessment of respiratory distress in bronchial asthma has been reported. Objectives: To evaluate the correlation between blood gas analysis and chest X-ray lung opacities in young children presenting with acute respiratory symptoms. Methods: Eighty patients (43 males and 37 females aged 0.5–24 months; mean B SD 9.1 B 7.2 months), either with acute wheezing respiratory symptoms and/or with crackles were enrolled in our study. In all children, blood gas analysis and chest X-rays were performed within 12 h following admission to the emergency department. Results: In 55 children (68.75%) chest X-rays demonstrated lung opacities. Subjects with normal X-rays had paO2 and SaO2 higher than subjects with lung opacities (p ! 0.0001 and p = 0.0001, respectively). Children with lung opacities almost always presented paO2 !80 mm Hg. Sensitivity and specificity for the presence of lung opacities of paO2 !80 mm Hg were 81 and 90%, respectively, while sensitivity and specificity of SaO2 !95% were 92 and 40%, respectively. paO2 !80 mm Hg in association with SaO2 !95% had a positive predictive value for the diagnosis of pneumonia of 90.9%. Conclusions: Our study suggests that blood gas analysis, particularly paO2, may help in predicting the presence of lung opacities in patients aged less than 2 years. However, chest X-rays may still be needed to define the actual extension of opacities as well as the possible concomitant presence of complications.