rosc lecture 2 part 2

8/12/2019 ROSC Lecture 2 Part 2

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Quality of chest compressions: rate

10-20 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90-100 100-110 110-120 R>120

Chest compression rate (rate per minute)

A m o u n t o f t i m e

a t a g i v e n r a

t e300

250

200

150

100

50

0

Abella et al, 2005



Clinical importance of chest compression rate

Abella et al, 2005

No ROSC

ROSC

10-20 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90-100 100-110 110-120 >120

Chest compression rate (per minute)

Mean rate, ROSC group

90 17

Mean rate,no ROSC group

79 18

210

180

150

120

90

60

30

0

A m o u n t o f t i



What this means: CPR guidelines 2010

New directions in CPR:

Hands-only CPR – evidencesuggests mouth-to-mouth maynot be required, especially forbystander response

New for 2010 guidelines:

Airway-Breathing-Circulationis now

Circulation-Airway-Breathing

CA B



Pause before shock

4:55 5:00 5:05 5:10

C o m p r e s s i o n s

E C G

Does CPR quality affect defibrillation?



0

20

40

60

80

100

≤10.3 10.5-13.9 14.4-30.4 ≥33.2

S h o c k s u c c e s s ,

% 90%

10%

55%

64%

Edelson et al, 2006

Pause before a shock – it really makes a big difference!

Pre-shock pause, sec



Adenosine triphosphate

How your cells store energy

(“charged battery”)

Adenosine diphosphate

Depleted energy store

(“spent battery”)

Visual model for how CPR may restore the heart

First, a little refresher from biology class….

energy

blood flow, oxygen



Visual model for how CPR may restore the heart



0-20 21-40 41-60 61-80 81-100

comp fraction, %

S u r v

i v a l t o d i s c

h a r g e ,

%

0

1 0

2 0

3 0

Compression “fraction” – amount of compressions given to a patient

Chr istenson J et al, Circ 2009

poo r surv iva l wi th lowest

compress ion fract ion in OHCA



40

32

24

16

8

0

1 2 3

CPR duration, min

C o r o n a

r y a r t e r y

B l o o d p

r e s s u r e

ICCM, 2005

2 inches vs 1.5 inches Survival:

100%

15%

The DETAILS of CPR delivery makes a big difference



More on chest compression depths

What is the role of chest compression depth during out-of-hospital

cardiac arrest resuscitation?

Ian G. Stiell, MD et al Critical Care Medicine 2012

20 30 40 50 60

0

1 0 %

2 0 %

3 0 %

s u

r v i v a l

compression depth

>2 inches



Aufderheide et al, 2004

Study of paramedic ventilations:mean ventilation rate was 30 per minute!(AHA recommended rate 8-10 per minute)

first group: 37 4 after retraining: 22 3

Does the quality of ventilations matter?

Slowerbreaths

Fasterbreaths



Aufderheide et al, 2004

Study of paramedic ventilations:mean ventilation rate was 30 per minute!(AHA recommended rate 8-10 per minute)

first group: 37 4 after retraining: 22 3

Does the quality of ventilations matter?

Slowerbreaths

Fasterbreaths

These rapid ventilations were tested in animals placed

in cardiac arrest and it KILLED ALL THE ANIMALSThe publication was entitled “DEATH BY HYPERVENTILATION”



May represent fatiguing (rescuer getting tired)

Other challenges to CPR performance: fatiguing during compressions



30 60 90 120 150

120

115

110

105

100

95

90

85

80

0

Time (sec)

C

C r a t e ( c o m p s p e r m i n )

Sugerman et al, Resusc 2009




30 60 90 120 150

Time (sec)

C C d e p t h ( m m )

Sugerman et al, Resusc 2009


55

50

45

40

35

0

rosc lecture 2 part 2

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