2. Resuscitation After Cardiac Arrest:
A 3 Phase Time Sensitive Model
The Electrical Phase: 0 to 4 minutes post VF onset
If defibrillation is achieved, excellent outcome
Little need for ventilation or drugs
The Circulatory Phase: 4 to 10minutes post VF onset
Cardiac and CNS hypoxia
Poor organ function even if defibrillation is achieved
Provide circulation to ‘prime the pump’
Re-fibrillation common – consider anti-arrhythmics
The Metabolic Phase: >10 minutes post VF onset
Consider hypothermia
Is epinephrine harmful?
Weisfeld et al, JAMA 2002;288:23
3. Improving ACLS
Delaying defibrillation (CPR first)
Improving CPR- better thoracic vacuum during
decompression
Mono vs. biphasic defibrillation
Constant vs. incrementing energy defibrillation
Vasopressors
Epinephrine
Vasopressin – only shown to be better in Asystole
Antiarrhythmic drugs
5. Why do we need to improve post
resuscitative care?
The median incidence of EMS-treated cardiac arrest
across sites was 52.1 per 100 000 population; survival
ranged from 3.0% to 16.3%, with a median of 8.4%.
Median ventricular fibrillation incidence was 12.6 per
100 000 population; survival ranged from 7.7% to
39.9%, with a median of 22.0% with significant
differences across sites for incidence and survival
When polled people believe that there is a 65%
survivability of cardiac arrest vs. the actual 8.4%
Graham Nichol; Elizabeth Thomas; Clifton W. Callaway; et al.
JAMA. 2008;300(12):1423-1431 (doi:10.1001/jama.300.12.1423)
6. Why should we????
Only 10% of cardiac arrests that arrive at hospital alive
survive to go home !
About 60% of cardiac arrest survivors regain
consciousness
1/3 experience irreversible cognitive disabilities
…this is where therapeutic hypothermia has its effect
7. Therapeutic Hypothermia
The goal of therapy =
initiate within 2-4 hours of return of spontaneous
circulation
target core temperature of 32-34°C reached within 6
hours after initiation of treatment.
Theory is based in its ability to prevent the cascade of
events following a cardiac arrest which inhibit
neurologic functioning
8. How it is thought to work
Slows ongoing hypoxic neurologic damage following
cardiac arrest
Several mechanisms:
Reduces cerebral metabolic rate
Suppresses free radical production
Suppresses excitatory amino acid release
Suppresses calcium shifts
Effects recognized since the 1950’s
9. Therapeutic Hypothermia to Improve
Neurologic Outcome After Cardiac Arrest
Hypothermia
after Cardiac
Arrest Study
Group, NEJM
2002;346(8): 549
11. Neurological Outcome and Survival
at 6 months
0%
10%
20%
30%
40%
50%
60%
Favorable Death
Normothermia
Hypothermia
NEJM 2002, 346:549
12. Standard of Care
AHA Guidelines Nov 2005
Unconscious adult patients with spontaneous
circulation after out-of-hospital cardiac arrest should
be cooled to:
32°C to 34°C
for 12 to 24 hours when the initial rhythm was
ventricular fibrillation (VF).
Such cooling may also be beneficial for other rhythms
or in-hospital cardiac arrest. (Level of Evidence: IIb)
CIRCULATION AHA :105, 166560 V1 (1).
13. Who should get cooled?
Greater than 18 years of age
Non-traumatic cardiac arrest due to ventricular
fibrillation or pulseless ventricular tachycardia
return of spontaneous circulation without full
neurological recovery (i.e. comatose)
14. Who should not get cooled
Pregnancy
Severe cardiogenic shock
Primary coagulopathies
DNR status
Coma unrelated to cardiac arrest
Received CPR greater than 45 minutes
Suffered a cardiac arrest that is not due to primary VF
or Vtach (e.g. PEA, asystole, non-cardiac, etc)
15. Various cooling methods
They differ greatly by time to cool and cost:
Ice bags at axillae & groin
Rapid infusion of cold saline
Cooling Blanket
ThermoSuit
Ice Bath (Artic Sun)
Neural Cooling device
16. Speeds of Cooling
Plattner O et al,
“Efficacy of
Intraoperative
Cooling Methods”,
Anesthesiology:
Volume 87(5)
November 1997 pp
1089-1095
17. What does the treatment involve?
Temperature goal 32° - 34° C. within 2-6 hours.
Monitor temperature with esophageal probe Q1h
MAP goal 60-80 mm/Hg
Maintain HOB at 30 ° C elevation.
No heated humidification on the ventilator
Maintain PO2 90 – 100 mmHg
Maintain pH within normal range
Begin enteric feeding as soon as practical.
Passively re-warm (no heating blanket) after 24 hours
of cooling has been completed.
18. Pre-Hospital Cooling
Richmond Ambulance Authority
The VCU and RAA initiative, known as the Advanced
Resuscitation Cooling Therapeutics and Intensive Care
Center (ARCTIC)return of spontaneous circulation,
from 25 percent in 2001 using conventional treatments
to 46 percent in 2008.
"Resuscitation and Survival Rates". Published by the Richmond Ambulance
Authority, November 16, 2009. retrieved 10-16-10
http://www.raaems.org/content/view/95/2/
19. Pre-Hospital Cooling
Richmond Ambulance Authority
In turn, the survival rate to hospital discharge
improved from 9.7 percent in 2003 to 17.9 percent at
the end of 2008. The national average is less than 7
percent.
"Resuscitation and Survival Rates". Published by the Richmond Ambulance
Authority, November 16, 2009. retrieved 10-16-10
http://www.raaems.org/content/view/95/2/
20. Pre-Hospital Cooling
Richmond Ambulance Authority
ARCTIC has two goals: to restart the heart as quickly as
possible following onset of cardiac arrest, and to
protect the brain by starting cooling as early as
possible and bringing resuscitated patients to a single
specialized post-resuscitation facility.
"Resuscitation and Survival Rates". Published by the Richmond Ambulance
Authority, November 16, 2009. retrieved 10-16-10
http://www.raaems.org/content/view/95/2/
21. Pre-Hospital Cooling
Richmond Ambulance Authority
Between 2001 and 2008, the team evaluated 1,598 cases
of adult, out-of-hospital cardiac arrest events in
Richmond, Va., and concluded that a building block
strategy comprised of a unique combination of
mechanical chest compressions, airway management,
drugs that restart the heart, and cold saline given
during resuscitation prior to the return of spontaneous
circulation, sequentially improved patient outcomes.
"Resuscitation and Survival Rates". Published by the Richmond Ambulance
Authority, November 16, 2009. retrieved 10-16-10
http://www.raaems.org/content/view/95/2/
