Vent Settings in ARDS: PEEP & Plateau Pressure

ARDS management focuses on lung-protective ventilation to avoid ventilator-induced lung injury (VILI).

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1. Plateau Pressure (Pplat)

Plateau pressure = pressure in the alveoli at end-inspiration (no airflow).

Goal Pplat < 30 cm H₂O

(to minimize barotrauma and volutrauma)

When to measure:

• Ventilator on volume control (AC/VC)

• Perform inspiratory hold for 0.5–1 second

• Read “Plateau pressure” on the vent

Interpretation:

• High Pplat (> 30) → poor lung compliance

  • ARDS

  • Pulmonary edema

  • Pneumonia

  • Atelectasis

What to do if Pplat > 30:

1. ↓ Tidal volume (to 6 → 5 → 4 mL/kg IBW)

2. ↑ PEEP cautiously

3. Prone patient if moderate–severe ARDS

4. Ensure no pneumothorax

5. Consider paralysis (cisatracurium)

6. Optimize fluid balance (negative)

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2. PEEP (Positive End-Expiratory Pressure)

PEEP prevents alveolar collapse and improves oxygenation.

Typical ARDS PEEP range: 10–20 cm H₂O

ARDSNet has two common strategies:

• Low PEEP–FiO₂ table (most common)

• High PEEP–FiO₂ table (for severe ARDS)

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3. ARDSNet  Low PEEP Table (Most Common)

Use this unless severe ARDS or proning.

FiO₂	PEEP
0.3	5–8
0.4	5–10
0.5	8–14
0.6	10–14
0.7	10–16
0.8	12–18
0.9	14–20
1.0	16–20

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4. ARDSNet  High PEEP Table (For Moderate–Severe ARDS)

FiO₂	PEEP
0.3	12
0.4	14
0.5	16
0.6	18
0.7	20
0.8	22
0.9	22–24
1.0	24

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5. How to Adjust PEEP in ARDS (Strategy)

If oxygenation is poor (PaO₂ low):

✔ ↑ PEEP
✔ ↑ FiO₂
✔ Prone positioning for PF < 150
✔ Consider paralysis for severe ARDS
✔ Negative fluid balance

If Pplat rises > 30 when PEEP increases:

✔ ↓ tidal volume
✔ Evaluate lung compliance
✔ Check for overdistention
✔ Consider switching to “high PEEP” strategy

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6. Driving Pressure (DP) — Newer Target

Driving pressure = Pplat – PEEP

Goal DP < 15 cm H₂O

Lower driving pressure = less mortality in ARDS.

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7. Example (Putting It Together)

Vent settings:
TV = 6 mL/kg IBW
PEEP = 12
FiO₂ = 0.6
Pplat = 28

→ OK. Pplat < 30
→ Driving pressure = 28 – 12 = 16 (slightly high)
→ Try PEEP 10 or reduce TV to 5 mL/kg

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ICU PEARLS

• Maintain tidal volume 4–6 mL/kg IBW

• Keep Pplat < 30

• Keep DP < 15

• Use higher PEEP for moderate–severe ARDS

• Prone if PF ratio < 150

• Use paralytics early in severe ARDS (first 24–48 hrs)

• Conservative fluid strategy improves outcomes