Abstract Background Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) have a major negative impact on health status, rates of hospitalization, readmission, disease progression and mortality. Non-invasive ventilation (NIV) is the standard therapy for hypercapnic acidotic respiratory failure in AECOPD. Despite its beneficial effects, NIV is often poorly tolerated (11-34 % failure rate). An increasing number of studies have documented a beneficial effect of nasal high-flow (NHF) in acute hypercapnia. We designed a prospective, randomized, multi-centre, open label, non-inferiority trial to compare treatment failure in nasal NHF vs NIV in patients with acidotic hypercapnic AECOPD. Methods The study was conducted in about 35 sites in Germany. Patients with hypercapnic AECOPD with respiratory acidosis (pH 7.35) were randomized 1:1 to NIV or NHF. The primary outcome was the combined endpoint of intubation, treatment failure or death at 72 h. The switch from one to the other device marks a device failure but acts as a rescue treatment in absence of intubation criteria. Results Due to recruitment difficulties, the study was terminated prematurely. A sample size of 720 was planned to have 80% power for showing that NHF is non-inferior to NIV with a margin of 8 percentage points. A total of 76 patients were randomised, with 38 in each group. The mean success rate from the linear model for NIV patients was estimated to be 82% and 54%. The success rate for NIV was 28% higher than that of NHF (95% CI 6 to 51%), p = 0.96. The probability of switching devices within 72h was estimated to be 9% for NIV patients and 46% for NHF. The rate for NIV is − 37% lower than that of NHF (95% CI − 57 to − 16%). Conclusion Slow recruitment means that robust conclusions cannot be made, but there are indications that NIV is superior to NHF in this setting, since it is common to switch from the NHF to the NIV device. These preliminary results must be augmented with an in-depth analysis regarding the causes for switching devices. This abstract is funded by: German Federal Ministry of Education and Research
Braunlich et al. (Fri,) studied this question.