Nocturnal non-invasive ventilation in COPD patients with prolonged hypercapnia after ventilatory support for acute respiratory failure: a randomised, controlled, parallel-group study

Key messages What is the key question?

What is the effect of nocturnal non-invasive positive pressure ventilation (NIV) alongside standard medical treatment in COPD patients with prolonged hypercapnia after ventilatory support for acute respiratory failure?

What is the bottom line?

We could not demonstrate an improvement in time to readmission or death by adding NIV for 1 year in COPD patients with prolonged hypercapnia after an episode of NIV for acute respiratory failure.

Why read on?

NIV did improve daytime PaCO₂ and night-time transcutaneous PCO₂ . This and the trend for improvement in health-related quality-of-life favouring NIV should be explored further.

Introduction

Non-invasive positive pressure ventilation (NIV) has become an established treatment in patients with COPD who are admitted to hospital with acute respiratory failure (ARF) due to an exacerbation. 1-4 As readmission and mortality rates in these patients are high, 5 6 the application of long-term nocturnal NIV in stable hypercapnic COPD has been subject of several studies. However, in a meta-analysis no clear benefits were documented. 7-11 Reasons for these negative results were: (1) insufficient ventilatory support; (2) lack of proper monitoring during the night; (3) baseline PaCO₂ too low; and (4) low adherence to NIV. The two long-term randomised controlled trials (RCTs) comparing NIV in addition to long-term oxygen therapy (LTOT) showed conflicting results: one demonstrated small improvements in daytime arterial carbon dioxide pressure (PaCO₂ ), dyspnoea and health-related quality-of-life (HRQL) 12 in favour of NIV whereas the other found an improvement in survival but at the cost of worsening HRQL. 13

Two other studies investigated the effects of long-term NIV in the most severe subgroup of COPD patients; that is, patients with acute-on-chronic respiratory failure. These indicated a benefit from long-term NIV in patients who previously required mechanical ventilation for treatment of ARF and who remained hypercapnic thereafter. 6 14 Unfortunately, these were both small studies and given the huge impact of COPD on mortality and morbidity 15 further studies are urgently needed.

We hypothesised that providing nocturnal NIV alongside standard medical treatment to patients who remain hypercapnic after ventilatory support during ARF would prolong the time to readmission for respiratory causes or death. Therefore, we conducted an RCT comparing nocturnal NIV with standard treatment for 1...