Previous studies of the effect of noninvasive positive pressure ventilation (NPPV) in chronic obstructive pulmonary disease (COPD) have not demonstrated strong evidence of an improvement in survival.
This study investigated the effect of using long-term NPPV to reduce hypercapnia and increase survival.
195 patients with advanced, stable hypercapnic COPD were randomly assigned to either continue standard treatment or to receive additional NPPV for at least 12 months.
The primary endpoint was 1-year all-cause mortality.
Secondary endpoints were arterial oxygen pressure (PaO2), arterial oxygen saturation (SaO2), pH, bicarbonate (HCO3), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), residual volume/total lung capacity, six-minute walk distance and three health-related quality of life summary measures.
67% of patients in the control group and 88% of patients in the intervention group were still alive 1 year after randomisation.
Continuous 1-year NPPV treatment was associated with significant improvements in PaO2, pH, bicarbonate FEV1 and health-related quality of life.
The authors commented:
"To our knowledge, this trial brings for the first time strong supporting evidence that NPPV targeted to greatly reduce PaCO2 (decrease baseline PaCO2 by ≥20% or achieve PaCO2 <6.5kPa [48.1 mm Hg]) improves long-term survival."
Kohnlein T, et al. Non-invasive positive pressure ventilation for the treatment of severe stable chronic obstructive pulmonary disease: a prospective, multicentre, randomised, controlled clinical trial. Lancet Respir Med 2014 Sep;2(9):698-705.