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
3
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
13
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