How ARDS should be

treated in 2017

2017, Ostrava

Luciano Gattinoni, MD, FRCP

Georg-August-Universität Göttingen

Germany

ARDS

1. Keep the patient alive

2. Cure the disease leading to the syndrome

3. Don‘t add damage

4. Provide the best environment for lung healing (???)

• lung

• body

• respiration

• circulation

Aim of the respiratory support

To buy time with minimal damage

Damaging factors

VentilatorLung

• Mechanical power

• Baby lung size

• Homogeneity

• Recruitability

VILI comes from

Small, inhomogeneous,

recruitable lung

Acute Respiratory Distress Syndrome

Timing Within 1 week of a known clinical insult or new/worsening respiratory symptoms

Chest Imaging a Bilateral opacities – not fully explained by effusions, lobar/lung collapse, or nodules

Origin of Edema

Respiratory failure not fully explained by cardiac failure or fluid overload;

Need objective assessment (e.g., echocardiography) to exclude hydrostatic edema if no risk

factor present

Mild Moderate Severe

Oxygenation b200<PaO2/FiO2< 300

with

PEEP or CPAP ≥ 5 cmH2Oc

100<PaO2/FiO2<200

with

PEEP ≥ 5 cmH2O

PaO2/FiO2<100

with

PEEP ≥ 5 cmH2O

aChest X-ray or CT ScanbIf altitude higher than 1000m,correction factor should be made as follows: PaO2/FiO2 x

(barometric pressure/760)cThis may be delivered non-invasively in the Mild ARDS group

JAMA. 2012;307(23):doi:10.1001/jama.2012.5669

PEEP 5 cmH2O

Clinical PEEP

MILD

PEEP

5 10 15 20

P/F

0

40

80

120

160

200

240

280

320

MODERATE

PEEP

5 10 15 20

P/F

0

40

80

120

160

200

240

280

320

SEVERE

PEEP

5 10 15 20

P/F

0

40

80

120

160

200

240

280

320

Caironi, et al. CCM 2015

MILD MODERATE

SEVERE

ARDS

Caironi, et al. CCM 2015

Baby lung

Gattinoni L et al. Intensive Care Med (1986) 12:137-142

CT

nu

mb

ers

fre

qu

en

cy

(%)

50

10

40

30

20

0

-900 -800 -700 -600 -500 -400 -300 -200 -100 0 100

CT numbers (Hounsfield Units)

-1000

Hyperinflate

d

No

rma

lly a

era

ted

Po

orly a

era

ted

No

n a

era

tedNormal

ARDS

Baby Lung

(1987)

Inhomogeneity

Voxel

Vgas

Weighted gas ratio = Vgas1/Vgas0 * fraction of tissue

Gas fraction = Vgas0/Vvoxel

Healthy subject

Moderate ARDS

Severe ARDS

Average ratio in normal subjects : 1.37±0.15

Ki/lung inhomogeneity interaction and gas/tissue

composition

MILD

MODERATE

SEVERE

Recruitability

5 cm H2O

PaO2: 97 mm Hg

d. 59% d. 56%

PaO2: 103 mm Hg

10 cm H2O

d. 53%

PaO2: 104 mm Hg

15 cm H2O

Morphological response (1986)

Intensive Care Med. 1986;12(3):137-42.

d. 70%

PaO2 : 34 mm Hg

5 cm H2O

d. 52%

PaO2 : 49 mm Hg

10 cm H2O

d. 32%

PaO2 : 121 mm Hg

15 cm H2O

0 20 40 60 80

0

20

40

60

80

100

6 dogs,

Oleic acid

Airway pressure [cmH2O]

%

recruitment

inflation

Potential for

recruitment 100%

Opening pressures (2001)

Pelosi et al. Am J Respir Crit Care Med. 2001 Jul 1;164(1):122-30.

Inflation %

5 patients,

ALI / ARDS

Paw [cmH2O]

Recru

itm

en

t an

d i

nfl

ati

on

%

0 5 10 15 20 25 30 35 40 45 50

0

20

40

60

80

100

Recruitment %

Inflation/Recruitment (2001)

Crotti et al. Am J Respir Crit Care Med 2001;

Potential for

recruitment 5%

potential for lung recruitment [% total lung weight]

Fre

quen

cy [

no. of

pat

ients

]

0

2

4

6

8

10

12

14

16

18

20

22

24

Figure 1

ALI patients

ARDS patients

higher

21 ± 10%

(374 ± 236 grams)

lower

5 ± 4%

(59 ± 51 grams)

Potential for lung recruitment

Gattinoni L, Caironi P, Cressoni M, Chiumello D, Ranieri VM, Quintel M,

Russo S, Cornejo R, Bugedo G, NEJM 2006, 354(17):1775-86

0 5 10 15 20 25 30 35 40 45

0

100

200

300

400

500

600

Pressure (cmH2O)

Rec

ruit

edlu

ng

tiss

ue

(g)

Opening Pressures

Mild ARDS (N=5)

Moderate ARDS (N=19)

Severe ARDS (N=19)

Courtesy of dr. Cressoni M.

Plateu pressure limit

A: TISSUE

Tissue (g)

0 50 100 150 200 250 300 350 400 450 500

Co

mp

artm

ents

(H

U)

-1000/-900

-900/-800

-800/-700

-700/-600

-600/-500

-500/-400

-400/-300

-300/-200

-200/-100

0/-100

>0

B: GAS

Gas (mL)

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700

-1000/-900

-900/-800

-800/-700

-700/-600

-600/-500

-500/-400

-400/-300

-300/-200

-200/-100

0/-100

>0

****

**

**

**

**

**

*

PEEP 5

PEEP 15

Chiumello, et al. AJRCCM 2016

Aim of the respiratory support

To buy time with minimal damage

Damaging factors

VentilatorLung

• Mechanical power

• Baby lung size

• Homogeneity

• Recruitability

Excessive power

VILI comes from

Time course of ventilator induced lung injury

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

Hours of mechanical ventilation

0 12 24 36 48 60

L

un

g W

eigh

t (g

)

-200

-100

0

100

200

300

400

500

600

Str

ain (

Vt/

FR

C)

0.5

1.0

1.5

2.0

2.5

3.0

Transpulmonary pressure (PL cmH2O)

0 4 8 12 16 20 24 28 32 36 40

40

50

60

70

80

90

100

%T

ota

l L

un

g C

ap

acit

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

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.

TLC

FRC

Lun

g V

olu

me

VT 100%

VPEEP 0%

VT 75%

VPEEP 25%

VT 50%

VPEEP 50%

VT 25%

VPEEP 75%

Protti et al. Crit Care Med. 2013 Feb 4.

Mechanical ventilation and VILI

1.Volume

2.Pressure

3.Respiratory Rate

4.Flow

5.Or???

Pressure

0 10 20 30 40 50 60

Volu

me

0

200

400

600

800

1000

1200

PE

EP

Pea

k

Pre

ssure

PEEP Volume

Total Inspiratory Volume

Pressure

0 10 20 30

Volu

me

0

200

400

600Z

EE

P

Pea

k

Pre

ssure

Total Inspiratory Volume

Pressure

0 10 20 30 40

Volu

me

0

200

400

600

800

1000

1200

PE

EP

Pea

k

Pre

ssure

PEEP Volume

Total Inspiratory Volume

EXAPLES OF ENERGY

COMPUTATIONS AT

DIFFERENT PRESSURES

ZEEP

LOW PEEP HIGH PEEP

(𝐸𝑟𝑠 ∙ ∆𝑉) + (𝑅𝑎𝑤 ∙ 𝐹) + 𝑃𝐸𝐸𝑃

Motion equation

Distend the lung Move the gas Keep open

𝑇𝑜𝑡𝑎𝑙 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒

=

Mechanical Power

Distend the lung Move the gas Keep open

𝑇𝑜𝑡𝑎𝑙 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒 ∙ ∆𝑉 ∙ 𝑅𝑅

=𝑃𝑜𝑤𝑒𝑟𝑟𝑠

= 0,098 ∙ 𝑅𝑅 ∙ ∆𝑉2 ∙1

2∙ 𝐸𝑟𝑠 + 𝑅𝑅 ∙

1 + 𝐼: 𝐸

60 ∙ 𝐼: 𝐸∙ 𝑅𝑎𝑤 + ∆𝑉 ∙ 𝑃𝐸𝐸𝑃

ENERGYTIME

Contributions to Power generation

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

RR TV Peep Driving Press

Percent increase variable

Perc

ent

incre

ase

pow

er

Baseline values

RR 20

TV (L) 0,400

Ers 25

I:E 0,5

Raw 10

PEEP 10

Powerrs 14,90

Summary

❖ ↑ TV Power 2

❖ ↑ ∆Paw Power 2

❖ ↑ RR Power 1.6

❖ ↑ PEEP Power 1

Interaction

Excessive power

VILI comes from

Small, inhomogeneous,

recruitable lung

Chest wall elastance

EtotEtot

cmH2O

StiffStiff

2525

LEEL

“Soft”“Soft”

EwEw

55

StiffStiff

1515

EwEw

“Soft”“Soft”

1515

LEEL

EtottotE

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 60

T

ran

spulm

on

ary

pla

teau

pre

ssue

(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

Slope PL/Paw = Ew/Etot [0.2 - 0.8]

Always

consider:

𝐕𝐓𝐁𝐚𝐛𝐲 𝐥𝐮𝐧𝐠 𝐬𝐢𝐳𝐞

The ARDS lung is small and not stiff

Normal VT

FRC=

500 ml

2500 ml= 0.2

ARDS VT

FRC=

500 ml

500 ml= 1

Always

consider:

The lung inhomogeneity

Stress raisers Atelectrauma

VV

V V

Lung expansion/gas-free state

STRESS RAISER=(10/1)2/3 = 4.64

10

1

Mead J J Appl Physiol. 1970 May;28(5):596-608.

Mild

(N=82)

Moderate

(N=71)

Severe

(N=12)P

Dishomogeneity 1.49 ± 0.17 1.58 ± 0.29 1.75 ± 0.41 0.03

Extent 0.3 ± 0.1 0.36 ± 0.16 0.46 ± 0.18 0.01

Intensity 2.69 ± 0.27 2.76 ± 0.27 2.84 ± 0.41 0.31

Am J Respir Crit Care Med. 2014 Jan 15;189(2):149-58

Lung dishomogeneity and ARDS

Dishomogeneity2/3 1.30 ± 0.31 1.36 ± 0.44 1.45 ± 0.55

Intensity2/3 1.93 ± 0.42 1.97 ± 0.42 2.01 ± 0.55

Lung Height (%)

1

5

6

7

4

3

2

0

0 20 806040 100

Gas

/ T

issu

e R

ati

o

ARDS Prone

ARDS Supine

Normal Supine

Normal Prone

The gas/tissue ratio as a function of lung height

Gattinoni L et al. In: Tobin MJ (ed) New York

Gattinoni L. et al. Minerva

Anestesiol. 2010 Jun;76(6):448-54

Guerin C. et al. N Engl J Med.

2013 Jun 6;368(23):2159-68

Atelectrauma

10

12

14

8

6

4

2

00 5 10 15 20

PEEP (cmH2O)

End Expiration

End Inspiration

Plateau Pressure (cmH2O)

**

31 ± 1.821 ± 1.8

**

26 ± 1.4

**

46 ± 3.238 ± 2.1R

ec

ruit

me

nt

(g)

Gattinoni et al. Am J Respir Crit Care Med 1995;151:1807-1814

Opening and closing (1995)

Recru

ited

tiss

ue

Pressure

Recruitment-Pressure curve

5 15 25 35

Exp.

Exp.

Opening-closing

Lung protective strategy

Less energy

+

More homogeneous lung