Patients with severe COPD have an indication for chronic noninvasive ventilation (NIV) in case they suffer chronic hypercapnia (PaCO2 > 6.0 kPa). However, the precise mechanisms by which chronic NIV leads to improved outcomes are not well understood, and it remains unclear what the intended goals of NIV should be. Additionally, approximately 30% of patients subjectively do not experience a relevant benefit from the treatment.
This thesis of Tim Raveling first summarizes the scientific evidence supporting chronic NIV. It also investigates the relationship between the improvement in hypercapnia and NIV outcomes (quality of life and survival). A final objective was to explore which COPD phenotype experiences the greatest improvement in quality of life.
There is sufficient scientific evidence to support the use of chronic NIV in COPD patients with chronic hypercapnia, but there is considerable variation in the change in quality of life after initiating NIV. Chronic NIV results in the greatest improvement in quality of life in patients with severe airflow obstruction, frequent COPD exacerbations, comorbid mood disorders, and in patients who are able to maintain the improvement in hypercapnia during daytime spontaneous breathing.
We concluded that it is insufficient to set the indication for chronic NIV solely based on the presence of chronic hypercapnia (a single PaCO2 value). To achieve a relevant improvement in quality of life, however, a significant reduction in hypercapnia must be targeted with NIV.
