title: Early lung function testing in infants with aortic arch anomalies identifies patients at risk for airway obstruction.
abstract: BACKGROUND
  Aortic arch anomalies (AAA) are rare cardio-vascular anomalies. Right-sided and double-sided aortic arch anomalies (RAAA, DAAA) are distinguished, both may cause airway obstructions. We studied the degree of airway obstruction in infants with AAA by neonatal lung function testing (LFT).
  
  
  METHODS
  17 patients (10 RAAA and 7 DAAA) with prenatal diagnosis of AAA were investigated. The median (range) post conception age at LFT was 40.3 (36.6-44.1) weeks, median body weight 3400 (2320-4665) g. Measurements included tidal breathing flow-volume loops (TBFVL), airway resistance (R(aw)) by bodyplethysmography and the maximal expiratory flow at functional residual capacity (V'(max)FRC) by rapid thoracic-abdominal compression (RTC) technique. V'(max)FRC was also expressed in Z-scores, based on published gender-, age and height-specific reference values.
  
  
  RESULTS
  Abnormal lung function tests were seen in both RAAA and DAAA infants. Compared to RAAA infants, infants with DAAA had significantly more expiratory flow limitations in the TBFVL, (86% vs. 30%, p<0.05) and a significantly increased R(aw) (p = 0.015). Despite a significant correlation between R(aw) and the Z-score of V'(max)FRC (r = 0.740, p<0.001), there were no statistically significant differences in V'(max)FRC and it's Z-scores between RAAA and DAAA infants. 4 (24%) infants (2 RAAA, 2 DAAA) were near or below the 10(th) percentile of V'(max)FRC, indicating a high risk for airway obstruction.
  
  
  CONCLUSIONS
  Both, infants with RAAA and DAAA, are at risk for airway obstruction and early LFT helps to identify and to monitor these infants. This may support the decision for therapeutic interventions before clinical symptoms arise.
authors.affiliation: Department of Neonatology, Charité Universitätsmedizin Berlin, Berlin, Germany. christoph.roehr@charite.de
authors.forename: Charles Christoph
authors.initials: CC
authors.lastname: Roehr
authors.forename: Silke
authors.initials: S
authors.lastname: Wilitzki
authors.forename: Bernd
authors.initials: B
authors.lastname: Opgen-Rhein
authors.forename: Karim
authors.initials: K
authors.lastname: Kalache
authors.forename: Hans
authors.initials: H
authors.lastname: Proquitté
authors.forename: Christoph
authors.initials: C
authors.lastname: Bührer
authors.forename: Gerd
authors.initials: G
authors.lastname: Schmalisch
mesh_terms: D000402:Airway Obstruction / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D001013:Aorta, Thoracic / Q000002:abnormalities* / Q000503:physiopathology*; D001015:Aortic Arch Syndromes / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008168:Lung / Q000503:physiopathology; D008297:Male; D015203:Reproducibility of Results; D012129:Respiratory Function Tests / Q000379:methods; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity