Pressure Control Ventilation
Definition
Pressure control ventilation provides a set inspiratory pressure to deliver the gas in the inspiratory phase and passive exhalation. The amount of volume needed to deliver the breath will vary.
- Peak inspiratory pressure (PIP) is the highest pressure at the end of inspiration.
- should be limited to 40 cm H2O in a healthy lung to avoid epithelial-alveolar damage.
- Positive end expiratory pressure (PEEP) retains positive pressure in the lungs during the exhalation phase of a mechanically started breath.
- increases the functional residual capacity of the lungs by increasing the surface area of the alveoli to enhance oxygenation.
- Traditionally, PEEP is started at 5 cm H2O and is increased as needed.
- Continuous positive airway pressure (CPAP) maintains a positive pressure through the breathing cycle.
- no cycling of pressures, it stays the same with inspiration and expiration, and the child initiates all breaths.
- Used to support oxygenation and work of breathing by keeping airways open.
- Pressure is delivered by
- Pressure control ventilation - similar to A/C; each triggered breath gets a set PIP and PEEP.
- Pressure support - amount of pressure applied to the airway during spontaneous inspiration by the patient. Pressure support can be used to support the patient initiated breaths during SIMV.
- Volume alarms are needed to alert the caregiver to changes in the amount of air inspired or expired by the child. The volume alarm reading is affected by trach tube or circuit leaks, as well as how the ventilator measures the volume. These are not as reliable as pressure alarms.
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- Advantage of pressure control ventilation is use as a mode for weaning vent support. May be more comfortable for a child who can breathe spontaneously.
- Disadvantage of pressure control ventilation is lack of reliable alarm systems. Changes in compliance or resistance of the lungs can potentially lead to hypoventilation.