The provision of long term ventilatory support to patients with chronic neuromuscular disorders is a major logistic, technical, and clinical challenge. In this issue of ThoraxBaydur and colleagues share their experiences with ventilatory support in this context.1 Much of their experience reflects the advances in technology that have evolved over the last six decades. Their initial experience was with negative pressure ventilation and later with positive pressure ventilation. Positive pressure ventilation has evolved from an invasive interface (the tracheostomy) to, in many situations, a non-invasive interface. Although negative pressure ventilation served their early patients well in the post-poliomyelitis epidemic, their experience with non-invasive ventilation—mouth or nasal intermittent positive pressure ventilation (MNIPPV)—indicates that, in both poliomyelitis and Duchenne's muscular dystrophy, MNIPPV is more effective.

The slow decline in forced vital capacity (FVC) over 24 years in the poliomyelitis group receiving negative pressure ventilation is remarkable. In the 25 patients studied the FVC declined by an average of 5 ml per year (0.1% …