The role of ventilation during CPR

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The role of ventilation during CPR

• Benjamin S. Abella, MD, MPhil
• Emergency Resuscitation Center
• Section of Emergency Medicine
• University of Chicago Hospitals
• Weekly code review April 8, 2005

E R C
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Guidelines optimal ventilation?
Ventilations good oxygenation maintain pH
(ventilation) Ventilations bad gastric
inflation ? increased abd pressure pauses in
chest compressions ? low CPP difficulty in
performing bystander reluctance increased
intrathoracic pressure
So what is the data?
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Chest compressions alone in out-of-hospital arrest
Bystander contacted 9-1-1
standard CPR (n279) chest compression
alone (n241)
29/279 (10.4) 35/241
(14.6)
Improvement, if any, due to ? less time to
train ? better CPR strategy
Hallstrom et al, 2000
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Chest compression/ventilation ratios
2.5 2.0 1.5 1.0 0.5 0


Neurologic deficit score
152 CC only 101 501 CPR
CPR CPR CPR
Survival 7 / 10 7 / 10 8 /
10 9 / 10 (ns)
Sanders et al, 2002
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Standard CPR (CCRB) vs. CC alone
1600 1200 800 400 0
iCPP (mm Hg sec)
CC only CC RB
0 2 4 6 8 10 12
Minutes of CPR
Berg et al, 2001
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Standard CPR (CCRB) vs. CC alone
Ao pressure
Time
chest compression
Berg et al, 2001
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Standard CPR (with breaths) vs. CC alone
Blood pressure
Time
chest compression
Berg et al, 2001
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Optimizing compressionventilation ratio during
CPR
computer modeling of resuscitaiton
1.40 1.20 1.00 0.80 0.60 0.40 0.20 0.00
Cardiac Output (L/min)
0 10 15 20 25 30 35 40 45
50
Number of compressions to each ventilation
Turner et al, 2004
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Optimizing compressionventilation ratio during
CPR
120 80 40 0
75 50 25 0
Flow/oxygen delivery index
Flow/oxygen delivery index
0 10 20 30 40 50
0 10 20 30 40 50
Compression/ventilation ratio
Compression/ventilation ratio
Professional Bystander
Babbs et al, 2002
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Measuring CPR
chest compression
ventilation
100 90 80 70 60 50 40 30 20 10 0
100 90 80 70 60 50 40 30 20 10 0
12 patients, 45 sec of recording per patient
Milander et al, 1995
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Hyperventilation in out-of-hospital cardiac arrest
16 seconds
v v v v v v v v
v v
mean ventilation rate 30 3.2
first group 37 4 after
retraining 22 3
Aufderheide et al, 2004
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Ventilation rates
200 180 160 140 120 100 80 60 40 20 0
n 454 segments mean rate 22.9 12.4
number of 30 sec segments
lt10 10-19 20-29
30-39 40-49
ventilation rate (breaths per minute)