Are sleep studies necessary in COPD?

While there are many research questions still requiring performance of research sleep studies in patients with COPD, their use is not advocated in routine clinical practice, except in patients who have symptoms of the sleep apnoea/hypopnoea syndrome or possibly in those without daytime hypoxaemia (PaO2 greater than 60 mmHg) who have marked polycythaemia or marked cor pulmonale.