Blood Gas Analysis and Chest X-Ray Findings in Infants and Preschool Children with Acute Airway Obstruction

Abstract

Background: 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 ± SD 9.1 ± 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.

Carbon dioxide tension as a reflection of different respiratory rates and chest x-ray features in children with community acquired pnemonia

“…9 Arterial PO 2 analysis may play a role in the diagnosis of hypoxemia in pediatric patients. 15 Arterial hypoxemia occurs whenever alveoli are under ventilated or overperfused, or the normal alveolar ventilationperfusion ratio of 4 units of ventilation to 5 units of blood flow is not maintained. 8,16 In pneumonia, hypoxemia is a hallmark of the disease.…”

“…8,16 In pneumonia, hypoxemia is a hallmark of the disease. 15 Hypoxemia in pneumonia usually due to uneven distribution of ventilation in relation to pulmonary capillary blood flow and impaired diffusion. 8,12,16 Abnormalities in the distribution of the ventilation and perfusion which is caused by increased area of under ventilated can cause intrapulmonary shunt.…”