Introduction Acute NIV is now standard therapy for hypercapnic respiratory failure (AHRF) complicating AECOPD. However, although chronic hypercapnia is an acknowledged poor prognostic factor in COPD and some data suggest a survival advantage with domiciliary NIV compared with oxygen alone, its use for chronic hypercapnic respiratory failure (CHRF) remains controversial.¹ Patients with CHRF who have recently been treated acutely with NIV for AECOPD may be a particularly appropriate group in whom to consider long term domiciliary NIV.

Method We are conducting an RCT (HOT HMV UK) of domiciliary NIV plus oxygen against domiciliary oxygen alone in CHRF (defined as PaCO₂ >7 kPa), focussing on patients who have recently received acute NIV for AECOPD, and we have evaluated the likely uptake of such treatment after resolution of the acute episode. All patients seen over a 5-month period at two tertiary centres for consideration of domiciliary NIV following acute NIV were assessed at least 2 weeks following resolution of AHRF and arterial blood gas analysis was performed.

Results 38 patients received acute NIV for an AECOPD. Mean (±SD) age was 69±17 years and 50% were male, with PaCO₂ of 9.3±2.4 kPa at acute presentation. Eight (21%) patients died prior to review (six during initial admission, two shortly following discharge); four patients whose diagnosis was clarified as an overlap of obstructive sleep apnoea and COPD were treated on clinical grounds with NIV and one patient was already receiving domiciliary NIV. Of the remaining 25 patients, nine had PaCO₂ <7 kPa at 2 weeks, leaving 16 (42%) with CHRF at 2 weeks post recovery. Importantly, seven (44%) of these did not wish to be considered for a clinical trial involving domiciliary NIV, the principal reason being poor tolerance during the acute episode.

Conclusion More than 40% of patients requiring NIV for AHRF complicating AECOPD had CHRF with a PaCO₂ >7 kPa, when assessed 2 weeks after discontinuation of acute NIV. However, nearly half of these reported negative experiences of acute NIV that made them reluctant to consider long term treatment.