Trans-Pulmonary Pressure - Critical care Mechanical ventilation platform

Critical care Mechanical ventilation platform

ICU Transpulmonary Pressure Simulator

Transpulmonary Pressure: P_L = P_aw − P_es

When a ventilator pushes air in, not all of that pressure reaches the lung itself — some is absorbed by the chest wall.
P_L is what’s left: the pressure actually stretching the lung.

Too little P_L → lung collapses at end-expiration (atelectrauma) · Too much P_L → lung is overstretched (volutrauma)

P_es (measured from the oesophagus) tells us how much pressure the chest wall is absorbing — so we can calculate what the lung is truly experiencing, something the ventilator screen alone can never show.

Note: P_es is a surrogate for pleural pressure, not a direct measurement. Mediastinal weight, balloon position and patient posture all introduce uncertainty (±3–5 cmH₂O). Interpret trends, not single absolute values.

⌨ Keyboard Shortcuts

Space

Pause / Resume animation

I

Inspiratory pause

Freezes waveform at end-inspiration to read plateau Paw and inspiratory PL

E

Expiratory pause

Freezes waveform at end-expiration to read PEEP and expiratory PL

1

Switch to Normal mechanics profile

2

Switch to ARDS profile

3

Switch to Obesity profile

F

Toggle fullscreen mode

Ideal for projector or bedside teaching

D

Toggle dark / light theme

?

Show / hide this shortcuts panel

Esc

Exit fullscreen or close this panel

Teaching mode

Score —

⚖️ Same settings — different patients

Adjust sliders to see how the same ventilator settings produce different pressures in each patient

PEEP 5 cmH₂O

Drive ΔP 18 cmH₂O

Normal

Paw plateau—

Pes—

Exp PL—

Insp PL—

ΔPL—

Obesity

Paw plateau—

Pes—

Exp PL—

Insp PL—

ΔPL—

ARDS

Paw plateau—

Pes—

Exp PL—

Insp PL—

ΔPL—

🧑‍⚕️ Patient

Normal mechanics

Lungs and chest wall are compliant. Risks are minimal at standard pressures.

🫁 Lung Cl 50 mL/cmH₂O

🦴 Chest wall Cw 100 mL/cmH₂O

⚙️ Ventilator Settings Pressure Control

PEEP 8 cmH₂O

Tidal Volume 8 mL/kg IBW

PAW

0

cmH₂O

PES

0

cmH₂O

Insp PL

—

cmH₂O

Overlay

Paw

0

Pes

0

PL

0

RR 12 /min I:E 1 : 2 T_i 1.67s

📊 Monitor

Paw

0

Pes

0

PL

0

PEEP titration guide

—

Insp P_L < 20–25 cmH₂O
Exp P_L 0 to +2 cmH₂O
ΔPaw < 15 cmH₂O (ARDS: <13)
ΔPL transpulmonary < 10–12 cmH₂O (ARDS)
PEEP titrated to Exp P_L 0–+2
Plateau Paw < 28–30 cmH₂O (ARDS)

Transpulmonary pressure is the pressure gradient across the lung — the difference between airway pressure and pleural pressure. Esophageal pressure (Pes) is a validated surrogate for pleural pressure in passively ventilated patients. When Pes is high (e.g. obesity), a high Paw may not reflect true lung stress — only P_L reveals what the lung is actually experiencing.

Oesophageal pressure is a surrogate for pleural pressure — not a direct measurement:

Mediastinal weight — the heart and surrounding structures add a positive offset (~3–5 cmH₂O) not present in true P_pl
Positional gradient — in supine patients, pleural pressure varies vertically (~0.2 cmH₂O/cm); Pes reflects mid-chest only, not dorsal or ventral regions
Balloon artefact — filling volume, catheter position (ideally lower third of oesophagus) and cardiac oscillations all affect signal quality
Elastance method — many centres use ΔPes/ΔPaw (elastance ratio) rather than absolute Pes to partially correct for mediastinal offset

In this simulator: PL is modelled using an elastance-derived approach (ΔPL = ΔPaw × Cl / [Cl+Cw]). Displayed values carry ±3–5 cmH₂O uncertainty. Interpret trends and relative changes rather than absolute numbers alone.

Step 1 of 7

⚡ Rapid-fire Quiz

Score: 0

Question 1 of 10

Educational use only. Values are modelled approximations based on simplified respiratory mechanics. This simulator is not a substitute for clinical judgment, bedside measurement, or institutional protocols. Transpulmonary pressure targets require validated esophageal manometry. Always assess individual patient physiology.