Non-invasive mechanical ventilation in the treatment of acute respiratory failure in chronic obstructive pulmonary disease.

Acute respiratory failure is usually managed by means of mechanical ventilation via an endotracheal tube or tracheostomy, when conservative treatment fails. Invasive mechanical ventilation is associated with several complications. The recent development of non-invasive methods of ventilation, has led to an attempt to avoid the complications of invasive mechanical ventilation during episodes of acute respiratory failure, ensuring at the same time a similar degree of efficacy. Both intermittent negative pressure ventilation and positive pressure ventilation by face or nasal mask have recently been used for this purpose. Negative pressure ventilation by means of iron lung, cuirass or poncho-wrap ventilators, has never been used in place of endotracheal intubation, and studies of this kind of ventilation are inconclusive: as a consequence, there is, at the moment, no indication for the generalized use of negative pressure ventilation in acute respiratory failure. Intermittent positive pressure ventilation by facial or nasal masks, has recently been used in the treatment of respiratory failure in place of endotracheal intubation. The results are promising, but remain controversial. It may be attempted in selected patients with obstructive respiratory disorders, but the procedure is very time-consuming for nurses.