Mechanical Ventilation Flashcards
Resistance
- How hard is it to get air in?
- The difficulty of a tube to carry gas
- opposition to airflow
- “airway resistance”
Difference between PIP and Plateau. The closer the plateau to PIP the lower the pressure loss
Compliance
- How difficult is it to inflate?
- Characteristics of the lung to make it strechy
- “static compliance”
- Balloon
Mandatory breath
- the start or end (or both) of the breath is determined by the ventilator, independent of the pt
Plateau pressure
- end inspiratory alveolar pressure attained during mechanical ventilation
- <30
Adaptive pressure control
A volume feedback mechanism for pressure-controlled or pressure supported breaths, the desired tidal volume is set and the vent adjusts the inspiratory pressure to deliver the minimal tidal volume
Flow triggering
A alternate to pressure triggering in mechanical vent, in which the vent responds to a change in flow rather than pressure drop
Mean airway pressure (MAP)
- Average airway pressure during a breathing cycle.
- directly related to insp time, RR and peak insp pressure and end- exp pressure
- <12
- associated with oxygenation
Positive end-expiratory pressure
PEEP
- Baseline pressure applied during exhalation with mech vent
- reestablished FRC and makes it easier for the pt to breath
Volume control
Vent controls the inspiratory flow and tidal volume;
tidal volume in this mode is delivered regardless of resistance or compliance
Pressure control
Airway pressure set and remains constant regardless of resistance or compliance
Auto-PEEP
End expiratory alveolar pressure that is greater than the pressure at the proximal airway, which results from high airway resistance and a short expiratory time
AKA air trapping
Breath stacking
Indications for mechanical ventilation
apnea
Acute ventilatory failure
Impending ventilatory failure
OD
Goals of mechanical ventilation
Provide adequate oxygenation
Provide adequate alveolar oxygenation
Avoid autoPEEP
Pulmonary barotrauma
Excessive pressure and volume delivery to the lung and is a consequence of alveolar overdistention to the point of rupture
Lung protective ventilator strategy
Vent technique where the target tidal volume is 6mL/kg of predicted body weight, the plateau pressure is kept below 30 cm H2O and PEEP is applied to maintain alveolar recruitment