[Pulmonary and nonpulmonary alterations in Duchenne muscular dystrophy]

To describe our experience in managing patients with Duchenne muscular dystrophy.

We analyzed the following variables in a group of 27 patients with Duchenne muscular dystrophy: arterial blood gases, lung function before and after mechanical ventilation, oxygen saturation (measured by pulse oximetry), nocturnal PaCO2 (measured transcutaneously by capnography), heart function, and dysphagia.

The mean (SD) age was 26 (6) years and the mean age at which mechanical ventilation had initiated in the patients was 21 (5) years. Sixty-two percent had undergone tracheostomy and invasive mechanical ventilation. Arterial blood gas levels returned to normal once mechanical ventilation was administered and remained so for the entire treatment period (mean duration of follow-up, 56 [49] months). Thirteen patients had cardiac symptoms and they all presented abnormal electrocardiograms and echocardiograms indicating dilated cardiomyopathy, left ventricular dysfunction, and posterior hypokinesis. Only 9 patients were receiving enteral nutrition (7 through a gastrostomy tube and 2 through a nasogastric tube). The videofluoroscopic swallowing study confirmed that dysphagia was related to neuromuscular disease rather than the presence or not of a tracheostomy. Five patients (18%), 4 of whom were receiving invasive mechanical ventilation, died during the follow-up period. Three patients had serious heart disease.

Mechanical ventilation confers clinical benefits and prolongs life expectancy in patients with Duchenne muscular dystrophy. Heart disease and feeding difficulties are determining factors in the prognosis of these patients.