Table 1.
Overview of long-term studies with nasal high-flow therapy in COPD patients
| Ref. | Study design | NHFT settings | Mean daily NHFT use, h | Population | Patients, n | Main results |
|---|---|---|---|---|---|---|
| COPD or bronchiectasis | ||||||
| [19] | RCT: NHFT vs. standard care (ambient air or LTOT) for 1 year | Flow 20–25 L/min, temp 37° C, FiO2 based on SaO2 | 1.6±0.67 | COPD or bronchiectasis (mean FEV1 45% pred.) | 108 | No difference in exacerbation frequency and hospital admission. Reduced number of exacerbation days and increased time to first exacerbation. Improved lung function and quality of life |
| Hypoxemic failure | ||||||
| [20] | RCT: NHFT/LTOT vs. LTOT for 1 year | Flow 20 L/min, oxygen supply 1.75±0.8 L/min | 6 | Hypoxemic COPD (PaO2 9.9 kPa during 1.6 L/min O2 and FEV1 31% pred.) | 200 | No difference in mortality or hospital admission. Reduced exacerbation rate and improvement in dyspnea symptoms, quality of life, PaCO2, and exercise capacity |
| Hypercapnic failure | ||||||
| [21] | Cross-over RCT: 6 weeks LTOT/NHFT vs. 6 weeks LTOT | Flow 29.2±1.9 L/min and 30.3±4.6 L/min | 7.1±1.5 and 8.6±2.9 | Stable hypercapnic COPD on LTOT (PaCO2 6.9 kPa, FEV1 29% pred.) | 30 | Improved quality of life, PaCO2, pH and nocturnal PtCO2. No differences in PaO2, lung function, exercise capacity, and physical activity |
| [24] | Cross-over: 6 weeks NHFT, thereafter 6 weeks NIV | Flow 20 L/min | Unknown (advice of 5 h) | Stable hypercapnic COPD (PaCO2 7.2 kPa, FEV1 30% pred.) | 11 | Reduction of capillary pCO2 compared to baseline, no difference in capillary pCO2 reduction between NHFT and NIV |
| [25] | Cross-over RCT: 6 weeks NHFT vs. 6 weeks NIV | Flow 19.8±0.6 L/min, O2 supply 2.2±0.9 L/min | 5.2±3.3 | Stable hypercapnic COPD (PaCO2 7.5 kPa, FEV1 29% pred.) | 102 | Reduction of pCO2 compared to baseline, no difference in pCO2 reduction and quality of life between NHFT and NIV |
COPD, chronic obstructive pulmonary disease; RCT, randomized controlled trial; NHFT, nasal high-flow therapy; LTOT, long-term oxygen therapy; FiO2, fraction of inspired oxygen; SaO2, oxygen saturation; FEV1, forced expiratory volume in 1 second; PaO2, partial arterial oxygen pressure; PaCO2, partial arterial carbon dioxide pressure; PtCO2, transcutaneous carbon dioxide pressure; NIV, noninvasive ventilation; pCO2, partial carbon dioxide pressure.