Long-term non-invasive ventilation in patients with chronic obstructive pulmonary disease (COPD): 2021 Canadian Thoracic Society Clinical Practice Guideline update

BACKGROUND: Chronic hypercapnic respiratory failure is common in advanced chronic obstructive pulmonary disease (COPD) and it is associated with adverse outcomes such as repeat hospitalization and death. Long-term non-invasive ventilation (NIV) has been used with uncertain efficacy in this condition, but recent clinical trials suggest possible survival benefit and reduced hospitalization under specific circumstances with this therapy. METHODS: The purpose of this guideline update is to assess current evidence regarding long-term NIV in the treatment of chronic hypercapnic respiratory failure specifically related to advanced COPD. A representative multidisciplinary panel of expert clinicians undertook a formal clinical practice guideline development process. Four key clinical questions were defined according to the Patient/problem, Intervention, Comparison, Outcome (PICO) approach. The panel performed a systematic literature review, assessed and graded the relevant evidence and made evidence-based recommendations. RESULTS: There is supportive evidence for the use of long-term NIV to improve survival in patients with stable COPD with significant chronic hypercapnic respiratory failure. The use of this therapy may also lead to reduced hospital readmission rates when applied to patients who were recently hospitalized for an acute hypercapnic exacerbation and in whom the elevated partial pressure of carbon dioxide in arterial blood (PaCO₂) persists 2 to 4 weeks after the index hospitalization. Studies demonstrating benefit of long-term NIV targeted very selected patient populations and used very specific methodology, both of which are likely key elements for NIV success. Although there is no evidence from clinical trials directly comparing high-intensity versus low-intensity NIV, most successful clinical trials have used the former ventilation strategy. Therefore, when opting for long-term NIV in patients with COPD and chronic hypercapnic respiratory failure, we suggest using high-intensity ventilation (sufficient inspiratory pressures to meaningfully reduce PaCO₂). We found no evidence to support the use of volume-assured pressure ventilation over standard pressure preset ventilation, which is currently the preferred mode. CONCLUSIONS: This 2021 guideline update represents an important shift from the previous recommendation against the use of long-term NIV in most patients with COPD and chronic hypercapnia, toward its suggested use. Based on the reported survival and hospital readmission rate benefits, we suggest long-term NIV in highly selected patients with COPD and chronic hypercapnic respiratory failure along with the use of specific and closely monitored ventilatory strategies.