Cardio Pulmonary interactions during CPR

Pr Jean-Christophe M Richard

Pôle SAMU 74 Urgence et Réanimation Centre Hospitalier Annecy Genevois

CONFLICTS OF INTEREST

- Air Liquide Medical Systems (part time)

Financial support for research (Genève /Annecy/Angers)

-VYGON (personal fee for lectures)

-SHILLER

-MAQUET (NAVA)

-COVIDIEN (PAV+) (personal fee for lectures)

-DRAGER (SmartCare)

-GE (FRC)

Circulation Ventilation

Classical interpretation of ventilation during CPR

• ETI + curarised subjects Manual CC

generates 156mL of VT (0 to 390mL)

• ETT + cardiac arrest subjects Manual

CC generates no VT

The median Vt per compression : 41.5 ml (33.0-62.1 ml)

which was considerably less than measured dead space

ml

a

bc

d

e f

a. Ressort

b. Soufflet

c. Seringue

d. Prise de pression

dans le soufflet

e. Entré d’air

f. Stylet et Papier

millimétrique

f

Pressure transmitted into the

thoracic compartment

Change in lung volume: Vt and

FRC

FRC

ml

Reduction in lung volume below FRC

FRC

Reduction in lung volume below FRC induced by Chest

compressions

Flo

w

Paw

V

olu

me

Lung volume reduction below

FRC

FRC

Cordioli et al. J Appl

Physiol 2016

Flow limitation at PEEP 0

PEEP 3 cmH20 PEEP 0 cmH20

Thoracic airways closure limiting inspiratory flow during Chest

compressions

Cordioli et al. J Appl

Physiol 2016

Cordioli et al. Curent Op Crit Care (submitted)

oxygenation

CO

2 e

limin

atio

n

Impact of thoracic airway closure on ventilation and gas exchanges

Vt expired : 319±165 ml (ICC 30:2) 341±142 ml (CCC 30:2)

Risks associated with 30:2 bag mask CPR: Gastric Inflation

CO2 depends on ventilation and circulation

Both depend on chest compression

Accidental observation: Periodic variation of EtCO2 during CPR

Capnogram (EtCO2 waveform) during CPR varies periodically with chest

compressions and ventilation….

CO2

Paw

Capnograms obtained during chest compressions in OHCA

CO2

Capnograms obtained during chest compressions in OHCA

CO2

CO

2

Airways opening

measurements

P-P

aw

CO

2

ITP

CO

2

Intra thoracic

measurements

Thiel cadaver model with CO2 (CAVIAR lab)

Thiel cadaver model with CO2 (CAVIAR lab)

Cordioli et al. Curent Op Crit Care (submitted)

Full Airway patency: PEEP 10 cmH2O Partial and complete airway closure: PEEP < Pclosing

Insufflation from the

ventilator

Alveolar CO2 CO2 Wash out by

fresh gas

How to interpret capnogram during chest compressions?

Insufflation from the

ventilator

Bench Model of CPR with additional CO2

D Luca Grieco et al. AJRCCM (Epub ahead of print)

Full Airway patency: PEEP 5 cmH2O Partial airway closure: PEEP 0 cmH2O

Time

CO2

CO2max

CO2min

CO2

CO2maxAOI =

Airway Opening Index : AOI

= 75%

AOI = 85%

The AOI permits to characterize and quantify oscillations on capnogram that is

correlated with alveolar ventilation

AOI = 5%

CLINICAL OBSERVATIONAL STUDY : 100 OHCA patients:

D Luca Grieco et al. AJRCCM (Epub ahead of print)

Maximal EtCO2 value is the best surrogate of alveolar CO2

0

25

50

75

100

Patients

CO

2 (

mm

Hg

)

OHCA

N=90 Patients

CLINICAL OBSERVATIONAL STUDY : 100 OHCA patients:

D Luca Grieco et al. AJRCCM (Epub ahead of print)

Thiel cadaver model with CO2 (CAVIAR lab)

D Luca Grieco et al. AJRCCM (Epub ahead of print)

CLINICAL OBSERVATIONAL STUDY : 100 OHCA

patients:

Clinical implications:

D Luca Grieco, et al. AJRCCM (Epub ahead of print)

SU

RV

IVA

L

TIME

Brain perfusion guided therapy

4 7 10

Airway Closure? guided

therapy

ETCO2 guided therapy

Annecy CPR Round Table :

Two phase time sensitive model to OHCA

High Quality CPR

Early Defibrillation

Cardiac Pump

Goal Directed Optimization

Cardiac and Thoracic Pump

Consider ECMO

• Ventilation during CPR should be revisited to be adapted to this specific context

• Thoracic airways closure may impair oxygenation and CO2 elimination during CPR.

• Only maximal value of exhaled CO2 during CPR reflect alveolar CO2

• Capnogram oscillations reflect thoracic airways patency and ventilation quality during

CPR

• EtCO2 monitoring during CPR is highly recommended but not adapted to CPR