High-Flow Nasal Cannula in Early Emergency Department Management of Acute Hypercapnic Respiratory Failure Due to Cardiogenic Pulmonary Edema.

Noninvasive ventilation (NIV) is the recommended ventilatory support for acute cardiogenic pulmonary edema (CPE) associated with acute respiratory failure or hypercapnia. High-flow nasal cannula (HFNC) has emerged as an alternative to NIV in acute hypoxemic respiratory failure. We aimed to assess the efficacy of HFNC on early changes in P_aCO2 and respiratory parameters in patients in the emergency department with acute hypercapnic CPE and to compare it to NIV.

We conducted a prospective observational study in consecutive emergency department patients with acute hypercapnic CPE. Subjects received either HFNC or NIV, according to the attending emergency physician's expertise in HFNC. The primary outcome was change in P_aCO2 after treatment for 1 h. Secondary outcomes were change in pH, breathing frequency, signs of work of breathing, and comparisons to NIV.

Twenty-seven subjects with a discharge diagnosis of hypercapnic CPE were analyzed. Subjects had a median age of 87 y (interquartile range [IQR] 78-93); 37% were male. Twelve (44%) received HFNC, and 15 (56%) received NIV. Median of changes in P_aCO2 from baseline to after 1 h of treatment were 7 mm Hg (IQR 4-11, P = .002) for HFNC and 3 mm Hg (IQR 1-8, P = .02) for NIV, with no between-group difference. pH, breathing frequency and signs of work of breathing also improved after both HFNC and NIV.

This preliminary study suggests that HFNC treatment for 1 h improves P_aCO2 and respiratory parameters in subjects with hypercapnic acute CPE in a manner that is comparable to NIV. Further studies are needed to assess HFNC as a possible alternative to NIV in early management of acute hypercapnic respiratory failure of cardiogenic origin. (ClinicalTrials.gov registration NCT03883555.).