Oxygen flow rate for CPAP use at 7.5 cmH2O pressure?

• A. 8 lpm
• B. 10 lpm
• C. 14 lpm
• D. 12 lpm

Answer: (B)

CPAP therapy relies on enough oxygen flow to keep the mask and circuit inflated at the set pressure while delivering adequate oxygen. At a CPAP level of 7.5 cmH2O, about 10 L/min of oxygen is a practical default that tends to maintain the intended pressure despite mask leaks and provide sufficient supplemental oxygen. Too little flow, like 8 L/min, may not sustain the pressure adequately, reducing the effectiveness of CPAP. Too much flow, such as 12 or 14 L/min, isn’t usually needed at this pressure and can waste oxygen and cause discomfort.