title: 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.
  
  
  OBJECTIVE
  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.
authors.affiliation: Department of Pediatric, University of Pisa, Italy. m.pifferi@med.unipi.it
authors.forename: Massimo
authors.initials: M
authors.lastname: Pifferi
authors.forename: Davide
authors.initials: D
authors.lastname: Caramella
authors.forename: Angelo
authors.initials: A
authors.lastname: Pietrobelli
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Ragazzo
authors.forename: Attilio L
authors.initials: AL
authors.lastname: Boner
mesh_terms: D000208:Acute Disease; D000402:Airway Obstruction / Q000097:blood* / Q000000981:diagnostic imaging* / Q000209:etiology; D001249:Asthma / Q000097:blood / Q000150:complications / Q000000981:diagnostic imaging; D015415:Biomarkers / Q000097:blood; D001784:Blood Gas Analysis; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010100:Oxygen / Q000097:blood*; D011237:Predictive Value of Tests; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D010100:Oxygen