Mechanical ventilation is a life support treatment, which is indicated when the patient's spontaneous breathing is inadequate to maintain life. It is also indicated as prophylaxis for imminent collapse of other physiologic functions, or ineffective gas exchange in the lungs. Mechanical ventilation may involve a machine called a ventilator, or the breathing may be assisted manually by a suitably qualified professional
Absolute humidity (AH, mgH2O/L
The actual amount of water vapor in a given volume of air; The weight per volume or as pound per 1,000 cubic feet.
Relative humidity (RH, %)
The amount of water vapor in the air, expressed as a percentage, of the maximum amount of water vapor that the air can hold at a given temperature; the ratio of actual water vapor pressure to the saturation vapor pressure.
- Humidity is essential to the human respiratory system. Dry air (about 6 mgH2O/L) enters the trachea and is subsequently conditioned by the tracheal and pulmonary mucosa, until the high humidity of the peripheral pulmonary airways (44 mgH2O/L) is reached. This point is called the Isothermal Saturation Boundary (ISB) where inhaled air has reached body temperature (37°C) and is 100% saturated with water.
- During mechanical ventilation and anesthesia, the air supplied to the patient is usually colder and drier than the regular air which may result in poor gas exchange and poor inflation of the bronchioles and alveoli.
- Humidity Therapy is a method to artificially condition the gas used in respiration of a patient as a therapeutically modality.
|IIsothermic saturation boundary (ISB)||37°C||44 mg/L|
|Medical O2 Gas||15°C||0.3 mg/L|
|Room temperature||22°C||7 mg/L|
|Oxygen therapy||ambient||16 mg/L|
|HME||25 ~ 30°C||17 ~ 32 mg/L|
|Heated humidifier||37°C||44 mg/L|
The supplied gas is optimally conditioned with heat and moisture from an electrically powered humidifier.
Including Heat and Moisture Exchanger (HME) and Heat and Moisture Exchanger Filter (HMEF).