Oxygen Therapy- Humidity For Low Flow Flashcards
What is the definition of humidification?
The act of adding water vapor to an anhydrous gas (a dry gas)
Humidity is water in a gaseous form or vapor.
What is absolute humidity?
The absolute humidity in a volume of gas expressed as a percentage of the water vapor capacity of the gas.
What is relative humidity?
The absolute humidity when saturated with water vapor expressed as a percentage.
How does the body naturally humidify air?
The body heats and humidifies air as it passes through the upper airway and deposits heat and humidity upon exhalation.
What is the Isothermic Saturation Boundary (ISB)?
The point in the upper airway where inspired gases are fully saturated with water vapor and warmed to body temperature.
What should the inspired gas have at the ISB?
100% relative humidity and a temperature of 98.6 degrees F (37 degrees C).
What problems arise from breathing dry gases?
Breathing dry gas moves the ISB deeper into the respiratory tract, leading to inflammation and infection of the lungs.
What are the effects of inadequate humidification?
Impacts epithelial integrity, increases susceptibility to infection, disrupts mucociliary transport, increases mucous production, and can cause structural lung damage.
What are the clinical uses for humidity therapy?
- During oxygen (O2) administration
- To increase room humidity
- To prevent thickened mucous
- To loosen thick secretions
- When the upper airway is bypassed
What factors affect the humidity output of a device?
- Temperature
- Surface area
- Exposure time
What is the principle of operation for a bubble humidifier?
Conducts gas down a tube submerged in water, breaking gas into small bubbles to increase surface area.
What is the typical absolute humidity level produced by bubble humidifiers?
Approximately 15 to 20 mg/L.
What should you check for when troubleshooting a bubble bottle?
- Kinked or squashed nasal cannula tubing
- Flowmeter high flow
- Patient for nasal obstructions
What are the hazards associated with bubble humidifier bottles?
Dysfunctional pressure relief valve can burst the bottle and high flow rates can produce aerosols transmitting bacteria.
