Purpose: High flow nasal cannula (HFNC) may decrease preload being associated with beneficial hemodynamic and respiratory effects in adults with heart failure.
Methods: This is a sequential intervention prospective study including 10 adults with New York Heart Association (NYHA) class III and left ventricle ejection fraction 45% or less. High flow gas was administered (fraction of inspired oxygen, 0.21) through nasal cannula (Optiflow(TM); Fisher & Paykel, Auckland, New Zealand). Sequential echocardiographies were performed at baseline, using HFNC with 20 lpm and 40 lpm and post-HFNC. A reduction greater than 20% in the estimated inspiratory collapse of the inferior vena cava (IVC) from baseline was considered clinically significant.
Results: Ten patients were included, with median age of 57 (44-65) years; 6 (60%) were female, and 8 (80%) had dilated cardiomyopathy. Median IVC inspiratory significantly (P<.05) decreased from baseline (37%) to HFNC with 20 lpm (28%) and HFNC with 40 lpm (21%), representing mean attributable reductions of 20% (95% confidence interval, 6-55) and 53% (95% confidence interval, 36-67) from baseline. Changes in the IVC inspiratory collapse were reversible after HFNC withdrawal. Respiratory rate was significantly reduced from 23 breaths per minute at baseline to 17 breaths per minute at HFNC with 20 lpm and 13 breaths per minute at HFNC with 40 lpm. In contrast, no significant changes in other echocardiographic or clinical variables were documented.
Conclusion: These findings suggest that patients with NYHA class III heart failure may benefit with HFNC supportive therapy.
Keywords: Heart failure; High flow nasal cannula.
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