Many thanks to Dr. Kudenchuk for sharing his slides The Science of CPR.

21
Many thanks to Dr. Kudenchuk for sharing his slides The Science of CPR

Transcript of Many thanks to Dr. Kudenchuk for sharing his slides The Science of CPR.

Page 1: Many thanks to Dr. Kudenchuk for sharing his slides The Science of CPR.

Many thanks to Dr. Kudenchuk for sharing his slides

The Science of CPR

Page 2: Many thanks to Dr. Kudenchuk for sharing his slides The Science of CPR.
Page 3: Many thanks to Dr. Kudenchuk for sharing his slides The Science of CPR.
Page 4: Many thanks to Dr. Kudenchuk for sharing his slides The Science of CPR.

“Shock first” 1990-93, n=639

“CPR first” 1994-96, n=478

p=0.04

1 2 3 4 5 >5

50

40

30

20

10

0

1st Unit Arrival Interval (min)1990-93 n=22 91 205 164 86 711994-96 n=14 80 164 114 65 41

% S

urvi

val

CPR Prior to ShockFirst rhythm VF; n=1117

Cobb LA et al. JAMA 1999;281:1182-1188

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Compression• Increased intrathoracic

pressure• Ejects blood from heart and

lungs• “Good” compression

increases forward output and BP Decompression (recoil)

• Decreased intrathoracic pressure

• Refilling of heart and lungs• “Good” recoil vacuum

refilling forward output

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Decompression(“diastole”)

Criley JM et al. Circulation 1986;74(IV):42-50.

Compression(“systole”)

Hemodynamics of CPR

RT ATRIUM

AortaRT ATRIUM

Organ perfusion

LEFT VENTRICLE

Heart + organ perfusion

EXTRATHORAIC VEINS

60

40

0

mm Hg

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Coronary Perfusion Pressure and ROSC in Human CPR

Paradis NA., et al. JAMA 1990;263:1106-1113

*CorPP = Aorta – RA pressure gradient during relaxation (diastolic) phase of precordial compression

15-19

0-14

20-24

25-39

40-45

36%

57%50%

100%

80%

0%

ROSCn=24 CorPP 25.6±7.7 mm Hg

No ROSC n= 76 CorPP 8.4±10 mm Hg

n=100 patients with cardiac arrest

55+ (normal)

Coro

nary

per

fusi

on p

ress

ure

(Cor

PP)

Coro

nary

per

fusi

on p

ress

ure

(Cor

PP)

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Edelson DP et al. Resuscitation 2006;71:137-45

• n = 60 consecutive VF resuscitations/shock− 63% men, 65 y/o− Time to 1st shock = 3.7min

• Measurements− Compression depth = mm during 30 sec before 1st shock

• Outcomes− Successful shock = VF terminated ≥ 5 sec− ROSC = organized rhythm/pulse/BP ≥ 20 min

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Edelson DP et al. Resuscitation 2006;71:137-45

Effect of CC Depth on Shock Success

ORadj*1.99/↑5 mm compression depth (95%CI 1-08-3-66, p=0.028)*Arrest location, age, sex, time-to-shock

AHA recommendations 1.5-2” (4-5 cm)

††

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CPR “systole”

Paused CPR

Aorta

RA

CPR “diastole”

3 secs16 secs

30 compressions

The Price of CPR Pauses

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Aufderheide TP et al. Resuscitation 2005;64:353-62

CPR Performance: Observed vs Perceivedn=30 (19 EMTs, 11 Paramedics)

Manikin study

75% (70-90)

82%(75-90)

80% (75-90)

90% (88-90)

Correct CPR Performance Parameters

(25th

-75th

qua

rtile

s)

(50/50)

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Aufderheide TP et al. Resuscitation 2005;64:353-62

CPR Performance: Observed vs Perceived

p=0.002

n=30 (19 EMTs, 11 Paramedics)Manikin study

47% (42-48)

75% (70-90)

82%(75-90)

26% (24-57)

80% (75-90)

8% (7-60)

90% (88-90)

99% (85-100)p=0.01 p=0.02

NSD

Correct CPR Performance Parameters

(25th

-75th

qua

rtile

s)

(50/50)

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Wik L et al JAMA 2005;293:299-304

• n=176 adults with out-of-hospital cardiac arrest• Automated resuscitation monitoring– Compression rate, depth, “hands off” time– Ventilation rate– ECG– Events

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Quality of CPR During Out-of-Hospital Cardiac Arrest

Wik L et al JAMA 2005;293:299-304

n=176

Vs AHA Guidelineschest compression

100 ± 10/min(75 @ 30:2)

Vs AHA Guidelinescompression depth38-52 mm (1.5-2”)

60 25

64 23

35 10

34 9

*Average # compressions given per minute vs instantaneous rate at which compressions, when given, were administered (120 20)

*

49% 21

48% 18

† % time without spontaneous circulation or chest compressions

~12%@ 30:2

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Yu T et al. Circulation 2002;106:368-372

• 20 instrumented swine• 7 minutes of unsupported VF

CPR + AED

“Hands-off” interval prior to each shock(mimicking analysis and charge interval of AEDs (10-19secs))

3 secs 10 secs 15 secs 20 secs

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Yu T et al. Circulation 2002;106:368-372

Effect of Interrupted Precordial Compression on Resuscitation Outcome

100%

80%

40%

0

Successfully Resuscitated

Seconds of Interrupted CPRn=5 per group

p<0.05 p<0.01

p<0.05

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• n=9 instrumented swine

• 6 minutes untreated VF standard CPR* x 3 min CPR with 75% recoil (residual 1.2 cm sternal compression @ end decompression)

x 1 min standard CPR* x 1 min defib x 3 ACLS

Yannopoulos D et al. Resuscitation 2005;64:363-72

*Standard CPR = CC @100/min, 50% duty cycle, 5 cm depth, full (100%) recoil, 15:2 ratio

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Effect of Incomplete Chest Decompression On Coronary and Cerebral Perfusion Pressures

†(MAP – mean ICP pressure)*(Ao Diastolic-RAP)

p<0.05

p<0.05

mm

Hg

% Chest recoil

Yannopoulos D et al. Resuscitation 2005;64:363-72; Paradis et al JAMA 1990;263:3257-8

n=9 instrumented swine std CPR (100% recoil) x 3’ CPR (75% recoil) x 1’

* †

Critical pressure for ROSC

*†

*†

*†

**

*

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Percent Survival fromWitnessed VF Rhythm

Importance of High-PerformanceResuscitation

35%0

10

20

30

40

50

60

2000 - 2004 2005 - 2009

perc

ent s

urvi

val

48%

New Protocol

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Take home points

• Quality of CPR is critical– Rate– Depth– Recoil

• High Density CPR (also ‘high performance CPR’)

– Achieved with a carefully choreographed approach– Chest compressions must occur 90% of the time

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Annual Utstein Survival for Chelan/Douglas Counties

2010 2011 20120%

10%

20%

30%

40%

50%

60%

30.0%*

41.7%

53.8%

*Incomplete data for 2010