Long-term outcomes in patients with COPD treated with non-invasive ventilation for acute hypercapnic respiratory failure

Chronic Obstructive Lung Disease (COPD) remains a major cause of morbidity and mortality across the world. We evaluated survival over 9 years in a cohort of patients with COPD requiring acute inpatient non-invasive ventilation (NIV). We analyzed prognostic indices to evaluate if they were associated with mortality.

We performed a retrospective chart review of all patients who were admitted to St. James’s Hospital respiratory ward with COPD and acute hypercapnic respiratory failure who required NIV over a 12-month period and followed their outcomes over 9 years. We investigated the association between survival and potential prognostic variables using univariate analysis and multivariate Cox proportional hazards model. We evaluated the association between survival and the following parameters: age, gender, multiple admissions requiring NIV (> 1 admission in within 12 months of index presentation), home NIV use preadmission, initial arterial blood gas pH, days spent on NIV, serum albumin and serum albumin to serum CRP ratio at admission.

Ninety-nine patients with COPD and acute hypercapnic respiratory failure were identified over a 12-month period from January to December 2011. Survival at 1, 2, 5 and 9 years was 65% (n = 64), 42% (n = 42), 25% (n = 25) and 21% (n = 21), respectively. Increasing age (p value < 0.001) and a lower serum albumin (p value < 0.005) were associated with a higher mortality. There was a trend towards improved survival in the group who were treated with home NIV prior to admission compared to no NIV therapy at home but this did not reach statistical significance (Fig. 3, p value = 0.088).

This study highlights the long-term mortality in patients with COPD admitted with hypercapnic respiratory failure requiring NIV and correlates with prior studies. Increasing age and lower serum albumin were associated with increased mortality. Home NIV may have a protective long-term survival benefit in patients with COPD who have been admitted for acute NIV.