Static images with a brief description
Alveolar Air Trapping
Alveolar Air Trapping: Gas remains in alveoli after exhalation. May occur secondary to incomplete expiration or disease state (such as COPD) that inhibits complete expiration.
Alveolar Forces
External pressure on alveoli occur due to elastic properties of the respiratory system or other forces such as alveolar collapse, chest wall or lung parenchyma [red arrows].
The blue arrows indicate resistive forces secondary to an artificial airway, for example.
APRV "False Flow Spike"
An initial spike may be seen during the release phase on the expiratory flow waveform. The expiratory spike represents expulsion of compressed gas from within the ventilator circuit and is typically seen with compliant ventilator tubing. This false peak flow spike does not represent an accurate measurement of the true peak gas flow. The true peak flow begins, and should be measured where the spike ends.
APRV: Normal T Low
Typical expiratory flow waveform during APRV. The release phase is represented below the horizontal axis. The expiratory flow waveform decelerates until the T Low is terminated. Therefore, the termination of the release phase flow is dependent on the release time. The release time or T Low in this illustration yeilds a release phase at approximately 50% of the peak expiratory flow. Also notice the Angle of Deceleration on a normal flow waveform is roughly 45 degrees.
APRV: Obstruction
In chronic obstructive pulmonary disease (COPD), airways lose supporting structure, thus resulting in airway obstruction and distal gas trapping. The collapsed airways function as a flow resistor and a flattened expiratory flow wave may result.
The "Angle of Deceleration" (ADEC) will be greater than 50 degrees. This phenomenon will also be seen with small artificial airways which also limit expiratory flow. The T Low may be lengthened to comepnsate for the smaller tube.
APRV: Overdistension
If the T Low is set too short or the P High too high, the patient's lungs may become over-inflated.
The expiratory gas flow waveform may demonstrate an extra "hump" as the patient actively exhales in the attempt to unload high lung volume.
Evita Infinity V500/ Babylog 8000 Modes Comparison
Use this chart to compare the modes in the neonatal range on the Evita Infinity V500 with the modes on the Babylog 8000.
Evita Infinity V500/ Evita XL: Modes Comparison
Use this chart to compare the various modes on the Evita Infinity V500 to the modes on the Evita XL.
