OBJECTIVE To quantitate prolongation of survival for patients with Duchenne muscular dystrophy with the use of noninvasive intermittent positive-pressure ventilation (IPPV) with and without access to a protocol involving mechanically assisted coughing. METHODS In this retrospective review of all patients with Duchenne muscular dystrophy visiting a neuromuscular disease clinic, patients were trained to use mouth piece and nasal IPPV and mechanically assisted coughing to maintain oxyhemoglobin saturation >94% (protocol). Survival was considered prolonged when noninvasive IPPV was required full time. RESULTS Ninety-one of 125 patients used noninvasive IPPV part time for 1.9 +/- 1.3 yr, and 51 went on to require it full time for 6.3 +/- 4.6 yr. Of the 31 noninvasive IPPV users who died without access to the protocol, 20 died from respiratory causes and seven died from cardiac causes. None of the 34 full-time noninvasive IPPV users with access to the protocol underwent tracheotomy or died from respiratory complications during a period of 5.4 +/- 4.0 yr, whereas three died from heart failure. Five patients with no breathing tolerance were extubated or decannulated to continuous noninvasive IPPV. CONCLUSIONS Noninvasive respiratory aids can prolong survival and permit extubation or decannulation of patients with Duchenne muscular dystrophy with no breathing tolerance.