Pressure Support Ventilation (PSV)
• Provides an augmented inspiration to a spontaneously breathing patient.
• The clinician selects an inspiratory pressure level, PEEP, and sensitivity.
When the patient initiates a breath, a high flow of gas is delivered
to the preselected pressure level, and pressure IS maintained throughout inspiration.
• The patient determines the parameters of VT, rate, and inspiratory time.
Pressure-Control Inverse Ratio Ventilation (PC-IRVI
• Combines pressure-limited ventilation with an inverse ratio of inspiration to expiration.
• The clinician selects the pressure level, rate, inspiratory time (121, 31, 411), and the PEEP level. With the prolonged inspiratory times, auto-PEEP may result.
• The auto-PEEP may be a desirable outcome of the inverse ratios.
• Some clinicians use PC without IRV.
• Conventional inspiratory times are used and rate, pressure level, and PEEP are selected.
Airway Pressure Release Ventilation (APRV,I
• Provides two levels of continuous positive airway pressure (CPAP) with timed releases, and permits spontaneous breathing throughout the respiratory cycle.
• The clinician selects both pressure high and pressure low along with time high and time low. Tidal volume is not a set variable and depends on the CPAP level, the patient's compliance and resistance, and spontaneous breathing effort.