What is the difference between low-flow and high-flow oxygen devices?

The distinction between low-flow and high-flow oxygen devices primarily revolves around the way they deliver oxygen concentrations to patients. Low-flow devices, such as nasal cannulas or simple face masks, typically deliver a variable concentration of oxygen, which can fluctuate based on the patient’s breathing pattern and the ambient air they may be inhaling along with the oxygen. This type of delivery system is generally characterized by its reliance on the patient’s own respiratory efforts, leading to variability in the actual oxygen concentration received.

Conversely, high-flow devices, such as venturi masks or high-flow nasal cannulas, are designed to provide a fixed concentration of oxygen, regardless of the patient’s breathing patterns. These devices mix a precise amount of oxygen with air through calibrated jets or precise mechanisms, ensuring that the patient receives a consistent concentration of oxygen, as specified.

The correct choice emphasizes this critical difference: low-flow devices allow for variability in oxygen concentration while high-flow devices maintain a fixed concentration. This understanding is crucial for clinicians when assessing and choosing appropriate oxygen therapy methods tailored to patients' specific respiratory needs.