Non-invasive ventilation for acute exacerbations of chronic obstructive pulmonary disease

Use it sooner rather than later to assist the “respiratory muscle pump”

Between a fifth and a third of patients admitted to hospital with hypercapnic respiratory failure secondary to acute exacerbation of chronic obstructive pulmonary disease will die in hospital, despite selective use of mechanical ventilation. 1 2 3 4 5 6 7 8 9 10 11 12 13 In severe chronic obstructive pulmonary disease, hyperinflation places the respiratory muscles at a mechanical disadvantage and they function close to their maximum capacity.14 15 During acute exacerbations, elastic and resistive loads on the respiratory muscles increase and may lead to ventilatory failure. The ensuing tissue acidosis further impairs respiratory muscle function, producing a vicious cycle.16 Thus a logical approach is to assist the compromised “respiratory muscle pump”.

Non-invasive positive pressure ventilation (NIPPV) employs a nasal or full face mask to administer ventilatory support from a flow generator and is established in the treatment of patients with a variety of chronic hypoventilatory syndromes. A role in acute exacerbation of chronic obstructive pulmonary disease (COPD) was suggested by early open and case control studies9 10 11 and has recently been confirmed by three randomised controlled trials (see 1).5 6 7