Respiratory impairment and airway closure in patients with untreated idiopathic scoliosis.

Fifty patients aged 11 to 78 years with untreated idiopathic scoliosis were studied. An increased frequency of respiratory impairment was found, especially in patients with a severe degree of scoliosis. Seven patients under 60 years were unable to work and all had thoracic curves exceeding 100°. None of the patients between 20 and 65 years of age was engaged in hard work and 22% had a disability pension, all because of respiratory impairment. A tendency to increased shortness of breath was noted with increasing curves as well as age. Dynamic and static spirometry was performed and airway closure was studied with the xenon-133 bolus technique. With increasing degrees of scoliosis there was a reduction in all lung volumes. Seventeen of 40 patients showed evidence of airway closure at lung volumes greater than functional residual capacity; 6 of these patients were under 40 years of age, and all had thoracic scoliosis exceeding 90°.