Low-flow nasal cannulas can only deliver a nasal cannula flow rate of 4-6 liters of oxygen per minute. They don't provide humidified or heated oxygen. So, they often dry out the nasal passages.

In the COVID-19 med-surg unit, more nasal cannulas were used, but on the COVID-19 ICU, more noninvasive ventilation masks were used, compared with their pre-COVID-19 numbers.