Transpulmonary pressure…

mislead by esophageal pressure ?

Marcelo B. P. Amato

University of São Paulo, Brazil

Critical Care Canadian Forum

CCCF, Toronto, November 2013

I disclose the following financial relationships with commercial entities that produce healthcare-related products or services relevant to the content I am presenting:

Company Relationship Content Area

Covidien Consultant Mechanical Ventilation

Philips / Dixtal Research grants E.I.T.

Conflict of Interest Disclosure

Marcelo B.P. Amato

-20

-15

-10

-5

0

5

0 0.5 1

Pes

Ppl

-20

-15

-10

-5

0

5

0 0.5 1

Pes

Ppl

Non-dependent (left b) Dependent (left D6)

• low PSV • strong effort

Pressure sensor: 1.2cm disk

Diaphragm (inner surface: the view from inside the thorax)

The dependent lung

Original Article

Mechanical Ventilation Guided by Esophageal Pressure in Acute Lung Injury

Daniel Talmor, M.D., M.P.H., Todd Sarge, M.D., Atul Malhotra, M.D., Carl R. O'Donnell, Sc.D., M.P.H., Ray Ritz, R.R.T., Alan Lisbon, M.D., Victor Novack, M.D., Ph.D., and

Stephen H. Loring, M.D.

N Engl J MedVolume 359(20):2095-2104

November 13, 2008

Chiu

mello

et a

l.

S. Loring et al.

15 !

Getting more information

Introducing noise

X

sensor

sensor sensor

C balloon = ?

sensor sensor

C balloon = ?

sensor

C balloon = ?

C esophagus = ?

Pes catheter

Collapse:

55.6 %

Patient # 9

Pneumocystis

carinii pneumonia

FIO2 = 100 %; VT = 4 mL/kg; PEEP = 5 cmH2O

FIO2 = 100 %; VT = 4 mL/kg; PEEP = 25 cmH2O

( after recruitment maneuver )

Collapse:

0.9 %

Patient # 9

Pneumocystis

carinii pneumonia

PplPpl

NON-DEPENDENT

PplPpl

MIDDLE

Ppl

DEPENDENT

Ppl

LOCAL TRANSPULMONARY PRESSURE MEASUREMENT

CHEST-WALL P-V CURVES(super-syringe)

PLEURAL PRESSURES (cmH2O)

0 4 8 12 16 20

VO

LU

ME

(ple

thysm

ogra

ph

- m

L)

0

300

600

900

1200

1500

1800

Normal

CHEST-WALL P-V CURVES(super-syringe)

PLEURAL PRESSURES (cmH2O)

0 4 8 12 16 20

VO

LU

ME

(ple

thysm

ogra

ph

- m

L)

0

300

600

900

1200

1500

1800

Injury

CHEST-WALL P-V CURVES(super-syringe)

PLEURAL PRESSURES (cmH2O)

0 4 8 12 16 20

VO

LU

ME

(ple

thysm

ogra

ph

- m

L)

0

300

600

900

1200

1500

1800

Pes

CHEST-WALL P-V CURVES(super-syringe)

PLEURAL PRESSURES (cmH2O)

0 4 8 12 16 20

VO

LU

ME

(ple

thysm

ogra

ph

- m

L)

0

300

600

900

1200

1500

1800

Slope: 0.91

0

5

10

15

20

25

30

0 5 10 15 20 25 30

20

10

0

-10

20

10

0

-10

Airway pressure

(cmH2O)

Pleural pressure

(cmH2O)

Occlusion test Tube clamp

at the end of expiration

∆ Airway pressure

(cmH2O)

∆ Pleural pressure

(cmH2O)

BA

Pes as a surrogate for Ppl

Baydur A. Am Rev Respir Dis 1982;126:788

∆Ppl: -10cmH2O

-10-10-10

-10

-10

-10

-10

-10-10

-10

Diaphragmatic contraction

diaphragmatic contraction uniformly lowers Ppl

at all points on the lung surface

Apical:

3th ICS

Basal:

8-9th ICS

Collapse:

55.6 %

Patient # 9

Pneumocystis

carinii pneumonia

FIO2 = 100 %; VT = 4 mL/kg; PEEP = 5 cmH2O

sensor sensor

C balloon = ?

sensor

C balloon = ?

C esophagus = ?

Protti & Gattinoni - 2011 - AJRCCM - Lung stress and

strain during mechanical ventilation - any safe limit ?

Talmor et al.- 2008 - NEJM

S. Loring.- 2011 - JAP

Balloon volume (mL of room air )

Esophageal p

ressure

(end-e

xpiratio

n)

Signal

Noise

Balloon volume (mL of room air )

∆ E

sophageal p

ressure

60%

PEEP (cmH2O)

Com

pla

ince

Chest-

Wall

60%

Getting more information

Introducing noise

X

P or PTP ?

( PAW - Pesoph )

c

Lung

Str

ain

0.5

1.0

1.5

2.0

2.5

3.0S

trai

n

No-VILI VILI

Pla

teau

pre

ssure

10

20

30

40

50D

rivi

ngpr

ess

ure

No-VILI VILI

Injury!!∆

PA

W-∆

PE

soph

Injury!!∆

PA

W

Note that,

↑ Offset in Pleural press.

↓ Chest-wallCompliance≠

35 cmH O2

P = p l

15

Transpulmonary:

20 cmH O2

P = p l

-5

35 cmH O2

Transpulmonary:

40 cmH O2

P

PL

P

35 cmH O2

P = p l

15

Transpulmonary:

20 cmH O2

P = p l

-5

35 cmH O2

Transpulmonary:

40 cmH O2

??

…Chest-Wall compliance during anesthesia

was comparable to that measured in

non-obese, healthy subjects…

…This may be surprising, bearing in mind

the voluminous fat layers over chest

and abdomen…

…Thus, a weight placed on the rib-cage

does not affect chest-wall compliance,

but simply displaces the pressure-volume

relationship towards higher pressures…

EPVENT

+ 4.3 cmH2O above average ( P < 0.001)

Alveoli ARDSnet Express LOVS

Pla

teau

pre

ssu

re

EPVENT

Alveoli ARDSnet Express LOVS

Dri

vin

gp

ress

ure

DR

IVIN

G-P

RE

SS

UR

E

(cm

H2O

)

Body-Mass Index

High PEEP studies; N = 2259 pts.

R2 = 0.00

Thank you!

Collapse:

55.6 %

Patient # 9

Pneumocystis

carinii pneumonia

FIO2 = 100 %; VT = 4 mL/kg; PEEP = 5 cmH2O

FIO2 = 100 %; VT = 4 mL/kg; PEEP = 25 cmH2O

( after recruitment maneuver )

Collapse:

0.9 %

Patient # 9

Pneumocystis

carinii pneumonia

sensor sensor

C balloon = ?

sensor

C balloon = ?

C esophagus = ?