Tranpulmonary pressure:

Why & How Esophageal

pressure

Luciano Gattinoni, MD, FRCP

Università di Milano

Fondazione IRCCS Ca’ Granda

Ospedale Maggiore Policlinico

Milan, Italy

2013, Toronto

How the

pleural

pressure is

generated

Volume (mL)

0 1000 2000 3000 4000 5000 6000

Ple

ura

l P

ress

ure

(cm

H2

O)

-30

-20

-10

0

10

20

Lung

Chest Wall

FRC

GaslessLung

Chest WallVolume

w/o Lung

Generation of pleural pressure

Level

1

2

3

4

5

6

7

8

9

10

Ventral

Dorsal

Ppl G/T

How to

measure the

pleural

pressure

Bo WJ, Wolfman NT, Krueger WA, Meschan I. 1990.

Basic Atlas of Sectional Anatomy with Correlated Imaging. 2nd edition; WB Saunders Co. page 99

Anatomical section of a frozen cadaver between the thoracic vertebra 8 and 9

Esophageal and gastric baloon

PES (cmH2O)

Pp

l (c

mH

2O)

PES and Ppl

6 dogs,oleic acid

Pelosi et al. Am J Respir Crit Care Med pp 122-130, 2001

5 10 15 20-50

-5

5

10

15

20

Inspiratory

Expiratory

Ppl1 Non dependent

Ppl3dependent

middlePpl2

Pleural

pressure and

mechanical

ventilation

Chest wall elastance

EtotEtot

cmH2O

StiffStiff

2525

LEEL

“Soft”“Soft”

EwEw

55

StiffStiff

1515

EwEw

“Soft”“Soft”

1515

LEEL

EtottotE

ΔPAW = ΔPL +ΔPpl

Driving

pressure

Drives

the lung

Drives

the chest

wall

Therefore…

It follows that:

EW/ETOT = (ΔPpl/ΔV) * (ΔV/ΔPAW) = ΔPpl/ΔPAW

ΔPpl = ΔPAW * EW/ETOT

Mechanical ventilation

ΔPL = ΔPAW * EL/ETOT

Airway plateau pressure (cmH2O)

0 10 20 30 40 50 60

0

10

20

30

40

50

60

Airway plateau pressure (cmH2O)

0 10 20 30 40 50 60T

ranspulm

ona

ry p

late

au p

ressue (

cm

H2O

)

0

10

20

30

40

50

60

A

Surgical control group

Medical control group ARDS patients

ALI patients

B

Chiumello et al, Am J Respir Crit Care Med. 2008

Strain (dVgas/Vgas0)

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Str

ess

(PL

, cm

H2

O)

0

5

10

15

20

25

30

35

40

45

50

55

Stress-strain curve of healthy pigs

Specific Lung

Elastance

5.8 cmH2O

Protti A. et al. Am J Respir Crit Care Med. 2011 Feb 4.

Transpulmonary pressure (PL cmH2O)

0 4 8 12 16 20 24 28 32 36 40

40

50

60

70

80

90

100

%To

tal

Lu

ng

Ca

pacit

y

0.0

1.0

2.0

Resting Biotrauma Stress at rupture

Agostoni,

Mead, Weibel,

Gattinoni

Specific Lung Elastance

12 (cmH2O)

1.5

0.5

Strain

1 2 3

Airway Pressure (cmH2O)

0 5 10 15 20 25 30 35 40 45 50

Ple

ura

l P

ress

ure

(cm

H2

O)

0

5

10

15

20

25

30

35

40

45

50

0.2

0.33

0.5

0.8

24

20.1

15

6

PL (cmH

2O) E

W/E

TOT

Mechanical ventilation

Pleural

pressure and

spontaneous

breathing

-ΔPmusc = ΔPW +ΔPpl

Driving

pressure

Drives

the chest

wall

Drives

the lung

Spontaneous breathing

-ΔPmusc = ΔPW +ΔPpl

-ΔPmusc = -ΔPmusc*EW/ETOT +ΔPpl

ΔPpl = -ΔPmusc*(1-EW/ETOT )

ΔPpl = -ΔPmusc*EL/ETOT

Spontaneous breathing

Airway Pressure (cmH2O)

0 5 10 15 20 25 30 35 40 45 50

Ple

ura

l P

ress

ure

(cm

H2

O)

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

0.8

0.67

0.5

0.2

24

20.1

15

6

PL (cmH

2O) EL/E

TOT

Spontaneous breathing

Muscular Pressure (cmH2O)

Mechanical

Ventilation

Spontaneous

Breathing

Driving Pressure

Lung Motor

Chest Wall Motor

Paw Pmusc

PL Ppl

Ppl Pmusc – Ppl = PW

Pleural pressure

during

spontaneous

breathing and

mechanical

ventilation

Mixed ventilation

ΔPpl = ΔPAW * EW/ETOT -ΔPmusc*EL/ETOT

Ppl = PAW * EW/ETOT -Pmusc*EL/ETOT+K

Pleural pressure is of paramount

importance when:

1. Setting mechanical ventilation

2. Estimating risks of VILI

3. Monitoring Spontaneous breathing

4. Monitoring non-invasive ventilation

Extensive application has to be made to

completely define its role in ICU practice

Conclusions