Update on Cardiopulmonary Resuscitation

Randall Brockman M.D.

Cardiologist/ElectrophysiologistMedical Officer for FDA

Circ System Devices Advisory PanelSept 2004

2

Several Goals

1. To address important issues in clinical trial design for new CPR devices

2. To provide a clinical summary of the history of CPR and devices to assist with #1

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Chain of Survival

• Rapid Access

• Cardiopulmonary resuscitation

• Early Defibrillation

• Advanced cardiopulmonary life support

4

The Beginnings of CPR

• Resuscitation of arrest patients has been attempted for over a century

• In the 1950’s, Safar et al and Elam et al “rediscovered” mouth to mouth

• In 1960, Kouwenhoven described chest compression

• These two techniques form the critical steps of modern CPR

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In-hospital Cardiac Arrest

• Essentially unchanged over the last three to four decades

• Return of spontaneous circulation (ROSC) in about 30% of patients

• Approximately 15% of patients are discharged neurologically intact

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Interposed Abdominal Counterpulsation14

0

10

20

30

40

50

60

ROSC Hosp D/C IntactNeuro

IAC

S-CPR

% occurrence

P=0.007

P=0.02

P=NS

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Out-of-hospital Arrest

• Hospital admission rates of 8-22%

• Survival to discharge with intact neurologic function 1-8%

• Largely unchanged despite multiple additions to the basic components of CPR

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No Long Term Benefit

• High dose epinephrine– Short term improvement (ROSC, hospital

admission) 17

– No long term improvement (hospital discharge and neurologic function) 17,18,19

• Vest CPR20

– Trend towards increased rate of ROSC and 24 hour survival but no difference in rate of hospital discharge

• Transcutaneous pacing21

– No improvement in rates of hospital admission or discharge

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Active-Compression Decompression

• Several studies found no improvement22,23

• Another study24 comparing ACD-CPR to S-CPR found improvement in several endpoints

05

1015202530354045

ROSC 24 Hr IntactNeuro Fx

ACD-CPR

S-CPR

% occurrence

P=0.0004

P=0.002

P=0.03

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Combination devices

• Inspiratory impedance threshold devices combined with ACD-CPR26,27

0

5

10

15

20

25

30

35

40

24 Hr HospD/C

24 Hr HospD/C

ACD-CPR+ ITD

S-CPR%

occurrence

P=0.033

P=0.41

P=0.02

P=0.63

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Automatic External Defibrillators28,29

0

10

20

30

40

50

60

Hosp D/C Intact Neuro Fx

all arrest

VF arrest%

occurrence

12

Public Access Defibrillation30

0

5

10

15

20

25

AED + CPR S-CPR

Survival to Hosp D/C

P=0.03

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Summary

• Survival rates with intact neurologic function have changed little over the past 30-40 years

• Choosing appropriate endpoints for clinical trials will be important to determine which devices will facilitate improvement in long-term outcomes

• Fostering an environment to enhance clinical research in this field will be important