Cardiac Arrest, Hypothermia and Resuscitation Science

Lecture 2: CPR – the foundation of resuscitation care

Benjamin S. Abella, MD MPhil

Clinical Research Director

Center for Resuscitation Science

Department of Emergency Medicine

University of Pennsylvania

Coursera

July 2012

An introductory course for the educated lay public and health care providers

Dr. Abella: conflicts of interest disclosures

Employment: University of Pennsylvania

Research funding: National Institutes of Health

Philips Healthcare

Medtronic Foundation

Consulting: Velomedix, Inc.

HeartSine Technologies

Volunteer: American Heart Association Sudden Cardiac Arrest Association

No equity or intellectual property related to resuscitation science

Refresher from Lecture 1: What is cardiac arrest?

Without any blood flow to the lungs or brain,

the victim of cardiac arrest is technically

“dead” and appears lifeless

(For brief minutes, may have “gasping” or

“seizure” activity)

The immediate actions required to restore blood flow:

1. Cardiopulmonary resuscitation (CPR)

2. Electrical defibrillation

Both of these can be done by the lay public

Refresher from Lecture 1: Survival from cardiac arrest is highly variable

Survival from cardiac arrest depends on where you live

From a large research study in 2008, showing survival to hospital discharge for victims of cardiac arrest:

Su

rviv

al to

dis

ch

arg

e

Dallas Pittsburgh Portland Seattle

4.5% 7.0%

10.6%

16.3%

Nichol et al, JAMA 2008

Why is survival so variable?

CPR is key to variable survival

In a given community:

Lay public factors:

How many people know CPR?

How many people deliver CPR?

What is the quality of the CPR?

Professional factors:

What is the time to professional CPR delivery?

What is the quality of professional CPR?

What do we know about CPR training among the lay public?

Many organizations offer CPR training:

American Heart Association American Red Cross

local training organizations

Millions trained each year, but most are health professionals

Performing re-certification

Imagine a map showing areas with High or low CPR training rates –

No such map exists!

What do we know about CPR delivery among the lay public?

Approx. 26-38% of cardiac arrest victims receive layperson CPR

In one large study, striking difference between private / public location

Home/private

public

Rate of bystander CPR

0 10 20 30 40 50

26%

45%

Weisfeldt et al, 2011

The quality of CPR makes a big difference in survival

Study of CPR in New York City

Lay public CPR was observed by

arriving EMS professionals

CPR quality was judged as “high”

or “low” quality

Victims receiving high quality CPR were FOUR TIMES more likely

To be resuscitated

Gallagher et al, 1995

Detailed study by Ken Nagao et al (Japan)

In Japan, some regions had emergency dispatch

protocols that INCLUDED breaths, and some that OMITTED breaths

Should we provide breaths during CPR?

Important to note: study of bystander

CPR provided by the public, and the

CPR wasn’t measured….

Investigators asked: did it matter?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

80

60

40

20

0

30

da

y s

urv

iva

l, %

Minutes from bystander CPR to defibrillator

Chest compressions only

standard CPR with breaths

SOS-KANTO et al, 2007

Breaths during public CPR don’t help, and they may hurt

Better survival with only

chest compressions, no

matter how long it took to

respond!

Bystander

contacted

9-1-1

survival to hospital discharge

11.5% 14.4%

standard CPR (n=960) chest compression alone (n=981)

The DETAILS of CPR delivery makes a big difference

CPR with chest compression alone or with rescue breathing

T Rea et al, 2010

Berg et al, 2001

Blo

od

pre

ssu

re

Time

= chest compression

Why pauses in chest compressions may be a bad thing

Berg et al, 2001

Blo

od

pre

ssu

re

Time

= chest compression

Few compression pauses lead to better blood flow