Fig. 2From: Effectiveness of nasal highflow in hypercapnic COPD patients is flow and leakage dependentPercentage decrease in capillary PCO2 in COPD patients after 1 h of NHF breathing under different experimental conditions. * = p < 0.05 vs. baseline; baseline PCO2 > 55 mmHg, a: n = 14, b: n = 11, c: n = 9, d: n = 9Back to article page