Invasive mechanical ventilation through a tracheostomy (TMV) is widely used to improve the survival of patients with severe restrictive respiratory disease caused by progressive neuromuscular disorders. For the last 20 yrs, there has been intense interest in noninvasive intermittent positive-pressure ventilation (NIMV) as a means of avoiding tracheostomy in these patients 1. However, there is no evidence that NIMV is beneficial before the development of daytime hypercapnia, and NIMV may even be detrimental by causing a delay in seeking medical advice during acute exacerbations. In keeping with this possibility, a randomized study in which Raphaël et al. 2 evaluated the effect of NIMV on patients with Duchenne's muscular dystrophy before the stage of daytime hypercapnia, found an unexpected higher risk of death in the group receiving NIMV. It can be argued that this study did not use appropriate inclusion criteria for selecting the subset of patients most likely to benefit from “preventive” NIMV. Another limitation of this …
