[Risk of respiratory insufficiency caused by thoracic rigidity].

Three patients, a man aged 71 and two women aged 47 and 54, were admitted for chronic obstructive pulmonary disease and cardiac failure. All three had thoracic deformities, owing to earlier pneumonectomy with thoracoplasty because of pulmonary tuberculosis, congenital kyphoscoliosis, and infant poliomyelitis respectively. Such patients are at risk of developing chronic respiratory insufficiency because of chronic alveolar hypoventilation: muscle power decreasing with age gradually fails to meet the increased respiratory labour. Often, the respiratory insufficiency is not noticed because the problems are ascribed to secondary chronic obstructive pulmonary disease or cardiac failure. The first sign of imminent respiratory insufficiency is nocturnal carbon dioxide accumulation. Therapy consists of respiratory assistance at night by positive air pressure ventilation via a nose mask.