Plateau pressure (Pplat): The pressure recorded during a pause at the end of inspiration. Because the Pplat is measured while there is no airflow, it reflects the static compliance of the respiratory system, including the alveoli, lung parenchyma, chest wall, and abdomen. This is a direct indication of alveolar function. Measured using an I-Hold in the Maneuvers menu. Pplat can be measured with a volume breath type only. If you want to measure Pplat in a pressure mode, switch to volume breaths to measure and then switch back. Pplat should be under 30 cmH2O. Higher or increasing values indicate a decrease in lung compliance.
Try to determine and fix the cause of decreased compliance (tension pneumothorax, pulmonary edema, positioning, etc). Disconnecting the vent is a short-term solution. Decrease rate, I:time, tidal volume or PEEP, starting with rate or I:time. Setting adjustments are situation dependent and you may not be able to adjust all of them. Remember that 6-8 mL/kg is normal VT, 4-6 mL/kg is for lung protection. Move down 1 mL/kg at a time. You may need to balance this with the rate to maintain minute volume (ie increase rate if you decrease tidal volume). Consistently high Pplat can lead to lung injury.
Causes of elevated Pplat (over 30 cmH2O)
- Increased tidal volume
- Decreased pulmonary compliance
- Pulmonary edema
- Pleural effusion
- Tension pneumothorax
- Ascites
- Obesity
- Patient positioning
- Abdominal packing
PIP vs Pplat
- An elevated PIP with normal Pplat indicates upper airway or resistance issues (mucous plug, kink, over breathing, etc) with normal lung compliance.
- PIP will raise if Pplat raises.