Humidity Defined

Optimal versus Essential Humidity

There are two levels of humidity appropriate for the airway: Optimal Humidity and Essential Humidity.

Optimal Humidity

37 °C, 44 mg/L,
100% Relative Humidity

During normal inspiration, the airway conditions inspired gases with heat and humidity to body temperature, 100% Relative Humidity with 44 mg/L of Absolute Humidity. The lungs rely on these optimal states to maintain the physiological balance of heat and moisture necessary for optimized airway defense and gas exchange while maintaining patient comfort.

Essential Humidity

31 °C, 32 mg/L,
100% Relative Humidity

The use of humidification with noninvasive mask therapies is essential for maintaining the natural balance of heat and moisture in the airways. The level of conditioning required is directed by the amount of humidity produced naturally in the nasopharynx when the patient is breathing through the nose.

Humidity Defined

Absolute Humidity

Relative Humidity

Temperature Affects Humidity

Size Does Matter