The effects of five years of nocturnal cuirass-assisted ventilation in chest wall disease

Abstract

We investigated the long-term effectiveness of cuirass-assisted ventilation, and examined whether mortality and morbidity could have been predicted at the time of admittance. Twenty five patients were commenced on nocturnal cuirass-assisted ventilation between 1983 and 1985, 10 with scoliosis or kyphosis, 8 with a thoracoplasty and 7 with neuromuscular disease. Mean pretreatment vital capacity was 30% of predicted, and arterial carbon dioxide tension (Paco2) was 8.2 kPa (62 mmHg). Fifteen patients were alive 5 yrs later. Two had discontinued assisted ventilation, both dying soon afterwards, and three had been changed to intermittent positive pressure ventilation. Survival could not have been predicted from age, severity of disease, lung volumes or arterial blood gases at presentation. Paco2 in the survivors had risen from a mean of 6.1 kPa (46 mmHg) after one year to 6.8 kPa (52 mmHg) after 5 yrs (p < 0.05), but remained significantly less than at presentation. There were no significant change in arterial oxygen tension (Pao2), lung volumes, respiratory muscle strength, haemoglobin, right heart failure, exercise tolerance, mental function and symptom scores after 5 yrs, compared to after 1 yr. The median amount of time spent in hospital declined from 15 days per patient in the first year after initial discharge with cuirass-assisted ventilation, to between 3-5.5 days per patient in subsequent years. We conclude that nocturnal cuirass-assisted ventilation bas a role in long-term management of patients with neuromuscular and skeletal chest wall disorders. A randomized comparison with nasal intermittent positive pressure ventilation is now indicated.