Humidification in CPAP Therapy

The following information is provided by: Fisher & Paykel Healthcare

How the Human Body Humidifies Air

Inspiration

One of the key functions of the nasal airway is to heat and humidify inspired gases. The nasal airway provides approximately 75% of the humidity added to each breath. The body heats the inspired gas to core body temperature and 100% RH by the time it reaches the gas exchange boundary in the lungs.

Expiration

When we expire, humidity is recovered from expired gases to humidify the next inspired breath. The remainder of the water requirement is supplied from the body's systematic reserves. Airflow generated by CPAP is greater than normal and overcomes the body's ability to heat and humidify the air 7,8.

A Cross Section of the Nasal Airway

As this MRI scan shows, the nasal airway is highly vascular, enabling it to be easily dried out by cold dry air.

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• The Role Of Humidification in CPAP Therapy
• What is Humidity?
• How the Human Body Humidifies Air
• CPAP Therapy Potential Problems
• Mouth leak and the Vicious Cycle
• Increase in Nasal Resistance
• Compliance With CPAP Therapy
• Frequently Asked Questions
• References