Plateau Pressure [Neurosurgery Wiki]

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====== Plateau Pressure ======

===== Plateau Pressure (Pplat) in Mechanical Ventilation =====

=== Definition ===
**Plateau [[pressure]] (Pplat)** is the pressure applied to **small airways and alveoli** during [[mechanical ventilation]] when airflow is momentarily paused at the end of inspiration. It reflects **lung compliance** and helps assess the risk of **ventilator-induced lung injury (VILI).**

=== How is Plateau Pressure Measured? ===
  * Measured using an **inspiratory pause maneuver** (0.5–1 second) on a ventilator.
  * Represents **static lung compliance** (not affected by airway resistance).
  * **Formula for Driving Pressure (ΔP):**  
    *'' ΔP = Pplat - PEEP ''*
  * Driving pressure is a key predictor of mortality in ventilated patients.

=== Recommended Target Values ===
  * **General ICU Patients & ARDS:**
    * '' Pplat ≤ 30 cmH₂O '' (to reduce risk of lung overdistension and barotrauma).
  * **Acute Brain Injury (ABI) Patients (e.g., TBI, ICH, SAH, Stroke):**
    * '' Pplat ≤ 25 cmH₂O '' (to minimize effects on cerebral perfusion).
    * Avoid excessive PEEP to prevent **increased intracranial pressure (ICP).**

=== Clinical Significance in ABI Patients (VENTIBRAIN Study) ===
  * Higher **Pplat was associated with increased ICU and 6-month mortality**.
  * **No strong correlation with neurological outcomes**.
  * Suggests **ventilation practices should balance lung protection with cerebral hemodynamics**.

=== High Plateau Pressure: Causes & Risks ===
  * **Decreased Lung Compliance:** ARDS, pneumonia, pulmonary edema, lung fibrosis.
  * **Excessive Tidal Volume:** Overdistension of alveoli.
  * **High PEEP:** Can elevate Pplat and affect venous return.
  * **Air Trapping (Auto-PEEP):** Common in obstructive lung diseases.

=== Strategies to Lower Pplat ===
  * **Reduce Tidal Volume (VT):** Target '' 4-6 mL/kg of predicted body weight (PBW) ''.
  * **Adjust PEEP Carefully:** Avoid excessive PEEP in ABI.
  * **Optimize Sedation & Paralysis:** If needed, to reduce patient-ventilator dysynchrony.
  * **Consider Recruitment Maneuvers:** If compliance is severely decreased (ARDS patients).

=== Key Takeaway ===
  * **Pplat ≤ 30 cmH₂O** is the general ICU goal.
  * **For ABI patients, Pplat ≤ 25 cmH₂O** may be preferable to avoid secondary brain injury.
  * **Higher Pplat increases mortality risk** but its effect on neurological outcomes remains uncertain.