Principles of Mechanical Ventilation. RET 2284 Module 3.0 Modes of Ventilation. Modes of Ventilation. Mode Description of a breath type and the timing of breath delivery
Modes of Ventilation
Do not lock the patient out of the ventilator!
“According to its purest definition, the term PEEP is defined as positive pressure at the end of exhalation during either spontaneous breathing or mechanical ventilation. However, use of the term commonly implies that the patient is also receiving mandatory breaths from a ventilator.” (Pilbeam)
NOTE: PEEP is intended to improve oxygenation, not to provide ventilation, which is the movement of air into the lungs followed by exhalation
PCV – SIMV with PSV
VC – SIMV with PSV
NOTE: During pressure support ventilation (PSV), inspiration ends if the inspiratory time (TI) exceeds a certain value. This most often occurs with a leak in the circuit. For example, a deflated cuff causes a large leak. The flow through the circuit might never drop to the flow cycle criterion required by the ventilator. Therefore, inspiratory flow, if not stopped would continue indefinitely. For this reason, all ventilators that provide pressure support also have a maximum inspiratory time.
Exercise: Using the PIP and thePPlateaufrom the pressure waveform below, recommend a pressure support setting for this patient (patient is in VC-SIMV mode)
Answer: 10 cm H2O
35 cm H2O
10 cm H2O
NOTE: The pressure difference between IPAP and EPAP is pressure support