The aim of treating stable COPD is to immediately relieve and reduce the impact of symptoms as well as reduce the risk of future exacerbations.1 According to the Global Strategy for the Diagnosis, Management and Prevention of COPD1 all patients who smoke should be encouraged to quit.
The guide also states that the mainstays of treatment are pharmacologic therapy with bronchodilators and corticosteroids, with patients at all stages of the disease benefiting from pulmonary rehabilitation programs.
Supplementary oxygen may be recommended in COPD patients with chronic respiratory failure who have severe resting hypoxemia, as a measure to improve blood oxygen levels.1
Oxygen and COPD
Evidence shows that long‐term oxygen therapy (LTOT) can benefit patients with COPD. A Cochrane review of randomised controlled trials found LTOT improved survival in COPD patients with severe hypoxaemia.2
Guidelines from the American Thoracic Society (ATS) also advise that "patients whose disease is stable on a full medical regimen, with PaO2 <7.3kPa (55 mmHg) (corresponding to a SaCO2 <88%), should receive LTOT".3
However, studies show that oxygen therapy does not address hypercapnia caused by failure of the ventilatory system as a long‐term consequence of COPD i.e, type 2 respiratory failure.4
NIV in treating COPD
Recent studies have shown that home noninvasive ventilation (NIV) using adequate pressure support in stable hypercapnic COPD patients can reduce the number of hospitalisations and improve mortality.5
The publication of a ground‐breaking study in The Lancet Respiratory Medicine found patients with chronic stable COPD who were assigned to home NIV treatment had improved survival and quality of life.5
The trial of 195 patients with stable GOLD stage IV COPD on standard therapy randomised patients to a control group or to NIV therapy targeted to reduce baseline PaCO₂ by 20% or more, or achieve PaCO₂ values lower than 6.5kPa (48.1mm Hg).
Results showed that NIV using adequate pressure support resulted in a one‐year mortality rate of 11.8% in the NIV group compared to 33.3% in the control group (HR 0.24%, CI 0.11‐0.49; p=0.0004).5
Patients who were randomised to NIV therapy at home also had a significant improvement in Health Related Quality of Life, as measured by the globally recognised St George’s Respiratory Questionnaire summary score.5
This latest data adds to a growing body of evidence showing that stable hypercapnic COPD patients can significantly benefit from NIV, particularly if an improvement in baseline PaCO₂ is the clinical target.5,6
A retrospective study of hospitalised hypercapnic patients with COPD found those given NIV therapy after discharge had improved event‐free survival (p=<0.0001) compared to similar patients not treated with NIV. Patients who received NIV therapy were also less likely to be re‐admitted to hospital compared to non‐treated patients (40% vs 75% p=<0.0001).7
Cranston, J. et al. Domiciliary oxygen for chronic obstructive pulmonary disease. Cochrane Review
Burt Christiana, Arrowsmith, Joseph. Respiratory Failure. Surgery 2009;27:475–479.
Koehnlein, T et al. Non‐invasive positive pressure ventilation for the treatment of severe, stable chronic obstructive pulmonary disease: a prospective, multicentre, randomised, controlled clinical trial. Lancet Resp Med 2014;2:698‐705.