Measuring respiratory function to wean patients from non-invasive ventilation in a ward environment

Non-invasive ventilation (NIV) is increasingly being introduced into various ward environments. NIV is usually used on wards to treat acute exacerbations of chronic obstructive pulmonary disease (COPD). In patients with COPD, carbon dioxide removal will be impaired. In critical care, arterial blood gas sampling remains the 'gold standard' for assessing carbon dioxide levels. Obtaining arterial blood gas samples in a ward environment is problematic, and potentially dangerous. There is currently no reliable substitute for arterial sampling to monitor for hypercapnia in ward areas.