Fig. 1From: Efficacy of high-flow nasal cannula in patients with acute heart failure: a systematic review and meta-analysisComparison of intubation rates. a High-flow nasal cannula oxygen (HFNC) versus conventional oxygen therapy (COT). b HFNC versus noninvasive ventilation (NIV). CI confidence interval, M-H Mantel-HaenszelBack to article page