Which oxygen delivery method is commonly used in CHF with pulmonary edema?

• A. High flow oxygen via NRB mask or HFNC
• B. Nasal cannula at 2 L/min
• C. Room air
• D. Simple face mask

Answer: (A)

In CHF with pulmonary edema, the main goal is to rapidly improve oxygenation because fluid-filled airspaces impair gas exchange and increase the work of breathing. Delivering the highest possible FiO2 reliably is the most effective way to raise arterial oxygen levels. A nonrebreather mask can provide near-maximum FiO2 when fitted properly and flows are adequate, making it a common initial choice to correct hypoxemia in this situation. High-flow nasal cannula also delivers high FiO2 with the added benefit of heated, humidified gas at high flow and a small amount of positive airway pressure, which helps keep airways open and reduces the work of breathing.

A nasal cannula at 2 L/min offers only a modest FiO2 and may be insufficient for significant hypoxemia. Room air provides no supplemental oxygen. A simple face mask can deliver more than a nasal cannula but typically does not achieve as high or as consistent FiO2 as a nonrebreather, and it lacks the positive pressure benefits of NRB or HFNC.

Thus, the approach most commonly used to rapidly correct hypoxemia in this scenario is high-flow oxygen via a nonrebreather mask or high-flow nasal cannula.