Figure 4

Respiratory function. (A) Per cent vital capacity (%VC) according to disease duration. The line is the regression line of %VC and disease duration. (B) Carbon dioxide partial pressure (pCO₂) according to disease duration. (C) Oxygen partial pressure (pO₂) according to disease duration. The triangles indicate levels in patients who had used non-invasive positive pressure ventilation. The cross (+) indicates the level in a patient who died after 42 years of disease duration of respiratory failure.