infant compression ventilation ratios jim tiballas

8/17/2019 Infant Compression Ventilation Ratios Jim Tiballas

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Resuscitation

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INFANT COMPRESSION-VENTILATION

RATIOS

Jim Tibbal ls

Resusc i tat ion Off icer, RCH

Conveno r, Paediatr ic Sub-Comm ittee,

Au stral ian Resusc i tat ion Counc i l (ARC)

ARC Paediatr ic Representative

Internat ional Liaison Comm ittee on Resusc i tat ion (ILCOR)


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Compression-ventilation ratios for infants

WHY do we have different ratios?


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Resuscitation

CouncilResearch Science to Reality

Guidelines ARC, ERC, AHA

Courses, Manuals

APLS, PALS

Evidence

EvaluationILCOR

EVIDENCE

JT 2011


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Resuscitation

CouncilResearch Science to Reality

Guidelines ARC, ERC, AHA

Courses, Manuals

APLS, PALS

Evidence

EvaluationILCORNO GOOD EVIDENCE

JT 2011


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Resuscitation

Council ARC Neonatal Guideline 13.1

„The exact age at which paediatric techniquesand in particular, compression-ventilation ratios,should replace neonatal methods is unknown,especially for very small premature infants.

For term infants beyond the newborn period,and particularly in those with known or

suspected cardiac aetiology of their arrest,paediatric techniques may be used (Class B,Expert Consensus Opinion)‟


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Council ARC Paediatric guideline 12.1

Cardiorespiratory Arrest - Compression-ventilation ratio for CPR

„The exact age at which … compression-ventilation ratio should replacethat used for newborns is not certain, especially for small prematureinfants

Infants whose cardiorespiratory physiology is in transition from an intra-uterine environment at birth to several hours after birth, i.e.,newborns, should be managed as per neonatal guidelines 13.1-13.10with a compression-ventilation ratio of 3:1

Infants aged more than a few hours beyond birth should be managedaccording to paediatric guidelines, particularly with a compression-ventilation ratio of 15:2 in the settings of pre-hospital, emergencydepartment, paediatric wards and paediatric intensive care units(Class A, Expert Consensus Opinion)2‟


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Council ARC Paediatric guideline 12.1

Cardiorespiratory Arrest - Compression-ventilation ratio for CPR

With the exception of newborns, all infants with known or suspected cardiacaetiology of cardiac arrest should be managed according to paediatric

guidelines regardless of location (Class A, Expert Consensus Opinion)2

with a compression-ventilation ratio of 15:2 if not intubated and (with)continuous compressions without interruption if intubated 2

Infants in cardiac arrest secondary to hypoxaemia should be treated initiallywith positive pressure ventilation and oxygen (Class A, Expert

Consensus Opinion)


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How did the ratios arise?

We tried to simulate spontaneous cardiac output and

ventilation …

Heart raterange

Respirationrate range

Ratio

newborn 100 -160 40 - 60 ≈ 2.6

3:1

1w – 3 mo 80 -160 30 - 40 ≈ 3.4

3 mo – 2 yr 80 -140 20 - 40 ≈ 3.7

2 yr – 10 yr 60 -100 14 - 24 ≈ 4.2

>10 yr 50 -100 12 - 20 ≈ 4.7

5:1


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For newborns … 3:1

For other infants, children and adults … 5:1


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CouncilBUT …

• For artificial cardiac output

• External cardiac compression achieves about one-

third of normal stroke volume

• Ventilation

• Spontaneous ventilation is by negative pressure –

which encourages venous return

• Artificial (mechanical) ventilation is by positive

pressure – which discourages venous return


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CouncilCPR CURRENT RECOMMENDATIONS

Newborns 3:1 (90 comp‟, 30 breaths/min)

Infants & Children 15:2 (comp‟ rate 100/min)

(interrupted BLS, continuous ALS)

Adults 30:2 (comp‟ rate 100/min)

(interrupted BLS, continuous ALS)


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Resuscitation

CouncilDrivers of change …

• Outcomes of adult cardiac arrest - poor

• Research on ratios

• End-tidal CO2 (PetCO2) monitoring


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Resuscitation

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Interruption of external cardiac compression


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Resuscitation

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In 176 arrests …

External Cardiac Compression …

• not given during 48% of arrest time


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Effects of interrupting chest compression on

calculated probability of successful defibrillation

during out-of-hospital cardiac arrest

5

1015

20

25

3035

40

45

50

0 5 10 15 20

Duration of hands-off, seconds/minute

P R O S C , %

Eftestol T et al: Circulation 2002;105:2270-3

n=156


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Adverse effect of pre-shock pause

JT 2011


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Important to NOT interrupt

external cardiac compression

JT 2011


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Why such adverse effects of

“hands off” ?


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Interruptions to compressions are

bad … • Are common …

• Reduce survival …

• Reduce probability of successful defibrillation

… should be minimised


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Ventilation during CPR


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Circulation. 2004;109: 1960-1965)

Results not dueto hypocarbia


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The mantra for external cardiac compression

PUSH HARD!

PUSH FAST!

DON’T INTERRUPT!

DON’T VENTILATE NORMALLY!


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Research on compression-ventilation ratios


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Resuscitation

CouncilCompression-ventilation ratios

• Different C:V ratios investigated in animalmodels, mannequins and computer simulations(100:2; 50:2; 50:5; 15:2; 30:2; 5:1)

• 30:2 shorter time to return of spontaneouscirculation and better oxygen delivery (animalmodels)

• Mathematical modelling favours 30:2 for oxygentransport


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Effects of low compression-

ventilation ratios, eg, 5:1

1. Too much "hands off" during CPR (adult studies only)

2. Interrupts external cardiac compression causing BP tofall to zero

3. Too much ventilation in proportion to a limited cardiacoutput.

4. Impedes venous return and hence cardiac output.5. Causes hypocarbia and cerebral vasoconstriction.


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JT 2011


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JT 2011


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• External cardiac compression achieves aboutone-third of normal stroke volume


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Council… so how much ventilation is

needed (for V/Q matching)?

30%30% blood flow

100% ventilation = 100-120mL/min/kg

30% ventilation = 30-36mL/min/kg

= 6/min x 5-6 mL/kg

“Adequate chest rise” in adult is 5-6 mL/kg

If

If

then

then

100% blood flow


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Importance of end-tidal CO2 monitoring


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Predicting outcome from adult

cardiac arrest

• When ROSC occurs, end-tidal CO2 (PetCO2)

increases (2 studies)

• Level of PetCO2 predicts ROSC (13 studies)

• PetCO2


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Partial pressure of end-tidal carbon dioxide successfully

predicts cardiopulmonary resuscitation in the field: a

prospective observational study. Kolar et al., Crit Care 2008; !2: R115

• 737 intubated cases out-of-hospital cardiac arrest

• After 20 minutes of CPR:

• 402 cases of ROSC when PetCO2 mean 33+/-9 mmHg

• 335 cases of non-ROSC when PetCO2 mean 7+/-2 mmHg

• PetCO2

14 mmHg reliably predicts (100%) ROSC


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Council Assessing effectiveness of CPR

Krep H, Mamier M, Breil

M, et al. Resuscitation.

2007;73(1):86.

JT 2011

Non ROSC – low end-tidal CO2

ROSC – normal end-tidal CO2


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End tidal CO2 is a quantitative measure of

cardiac arrest. Sehra et al., PACE 2003; 26: 515-617

31 adults

Defibrillator

implantation


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Principles of Guideline Formulation

Survival = Science x Education x Implementation

JT 2011


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Why 15:2 not 30:2 for paediatrics?

• No human evidence

• Consensus with adult scientists NOT achieved. (Paediatricians notpersuaded by cardiac arrest studies in animals, mannekin or computersimulations)

• Rationale conjecture:• Paediatric ventilation requirement greater than adult

• Hypoxic arrest, not sudden arrhythmia arrest, more common inpaediatric practice

• In out-of-hospital paediatric cardiac arrest (Kitamura et al., Lancet 2010;375: 1347)

• Survival from asphyxial cause better (7.2%) with standard CPR(7.2%) vs compression-only CPR (1.6%) vs no CPR (1.5%)

• Survival from cardiac cause same with standard CPR (9.9%) vscompression-only CPR (8.9%) vs no CPR (4.1%)

• 15:2 previously used for children (one-person rescue)


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But … ventilations after intubation

ILCOR

“reduce”

AHA8-10/min (no circ)

12-20/min (circ)

ARC & NZRC10/min

ERC

10-12/min

JT 2011

2010


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Council ALS CURRENT RECOMMENDATIONS

(intubated)

Newborns 3:1 (90 comp‟, 30 breaths)

compressions interrupted

Infants

Children 10:1 (100 comp‟, 10 breaths)

compressions continuous

Adults 10:1, 15:1 (100 comp‟, 10-6 breaths)

compressions continuous


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... What is the best ratio for infants?

#*&^!

Whatever achieves adequate simultaneous

pulmonary blood flow and ventilation


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• Always monitor PetCO2 !

• During infant CPR – whatever ratio

• “Fine tune” compressions and ventilation

– Absent PetCO2

? Not intubated

– Low PetCO2

? Excessive ventilation? Inadequate compressions

? Both of above

– High PetCO2


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... the debate will continue, after all …

“Il n‟est pas nécessaire de tenir les choses

pour en raisonner ” (Pierre Beaumarchais. Le Barbier de Séville)

“It‟s not necessary to understand things inorder to argue about them ”
http://en.wikipedia.org/wiki/Le_Barbier_de_S%C3%A9villehttp://en.wikipedia.org/wiki/Le_Barbier_de_S%C3%A9ville

infant compression ventilation ratios jim tiballas

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