Persistence and Progression of Airway Obstruction in Children With Early Onset Scoliosis.

Abstract

Obstructive lung disease occurs in 30% of children with early onset scoliosis (EOS); changes in degree of airway obstruction over time have not been reported. Longitudinal patterns of incidental, persistent, and progressive airway obstruction were retrospectively analyzed in a cohort of children with EOS with at least 1 forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) value <85% on serial spirometric assessments over a ≥3-year observation period. The prevalence of clinical features and the severity of coronal and sagittal spine deformities for each group at the beginning and end of the study period were compared. Airway obstruction was incidental in 12 (24%) and persistent in 37 (76%) of 49 children with EOS. Twenty of 37 (54%) of those with persistent obstruction developed progressive airway obstruction. The decline in FEV1/FVC over 6±2 years was insignificant in the incidental group (4%±2%) and the persistent nonprogressive group (7%±4%) but significant in the progressive group (13%±4%, t test; P=0.002). In total, 29% of the 49 children at the onset and 57% at the end of the study had airway obstruction. The incidental, persistent nonprogressive, and progressive groups did not differ with regard to age, diagnosis distribution, or sex. The initial coronal curve size, apex, direction of the curve, and degree of kyphosis were statistically similar among the 3 groups. Coronal curve magnitude inversely correlated with FEV1/FVC at the end but not the beginning of the study (r=-0.19, P=0.002). Six of 19 responded to bronchodilator treatment, suggesting concurrent asthma. Airway obstruction did not relate to restrictive pulmonary abnormalities measured by FVC at first or last timepoints [slope=-0.076 (95% confidence interval, -0.99 to 0.038; P=0.19)]. Changes in degrees of airway obstruction and restrictive lung disease over time did not correlate [slope=-0.125 (95% confidence interval, -0.294 to 0.044; P=0.14)]. Children with EOS and progressive airway obstruction represent an important subgroup which may require new surgical and nonsurgical treatment strategies to prevent loss of lung function over time.