Improvement in hypercapnia does not predict survival in COPD patients on chronic noninvasive ventilation.

Purpose: It has recently been shown that chronic noninvasive ventilation (NIV) improves a number of outcomes including survival, in patients with stable hypercapnic COPD. However, the mechanisms responsible for these improved outcomes are still unknown. The aim of the present study was to identify parameters associated with: 1) an improved arterial partial pressure of carbon dioxide (PaCO) and 2) survival, in a cohort of hypercapnic COPD patients treated with chronic NIV.