Timing of Implementation of Therapeutic
Hypothermia Post Cardiac Arrest
OHSU School of Nursing – Monmouth
NRS 322 – Acute Nursing II
Instructors – Bret Lyman & Allison Kooistra
Senior Student Nurse (Project Leader) – Kira Biron
Junior Student Nurses - Sarah Aulerich, Kylee Bell,
John Brun, Melissa Knudsen, Amy Pieren, Oscar Ramos,
Megan Vorderstrasse & Kimberly Washburn
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Out-of-hospital cardiac arrest (OHCA) is a
leading cause of mortality and severe
neurological disability.
Recent literature suggests that therapeutic
hypothermia can improve survival and
neurological outcome in some groups of
comatose patients after cardiac arrest.
Uncertainty exists over the best way (method)
and at what point to implement this treatment
to assure best outcomes.
Therapeutic Hypothermia is already
implemented in the ICU using the
Alsius endovascular cooling system,
but some talk has been done to
possibly start the process sooner &
consistently in the ED with other
bridging methods.
Is a process of systematically & safely
lowering a patient’s overall body
temperature to a target of 33 C (91.4 F)
degrees to slow down cell death which
can increase the chance of full
neurological recovery.
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Decreases free radical production & dangerous buildup
of calcium levels
Decreases intracranial pressure
Decreases cerebral metabolic rate as well as its need for
oxygen and glucose
Decreases the damage that cerebral reperfusion injury
can produce on patients with ROSC
Prevents mitochondrial damage & breakdown,
reducing tissue necrosis and/or apoptosis
Prevents immune system attack on cells due to
abnormal ion levels
Provides a better chance of recovery with intact
neurological function
P
O
Patients with return of spontaneous
circulation after cardiopulmonary
arrest who remain comatose upon
admission
Intervention Therapeutic hypothermia in the prehospital or ED setting
Comparison Therapeutic hypothermia in the ICU
setting (Is the sooner the better?)
Outcome
Neurological outcome
T
Time
I
C
Population
Until death or hospital discharge (6
months after D/C)
“For patients with return of spontaneous
circulation (ROSC) after cardiopulmonary
arrest who remain comatose upon
admission, does sooner implementation of
Therapeutic Hypothermia in the prehospital or ED setting as compared to later
implantation in the ICU, make a difference
in neurological outcomes over time”
The following key variables/terms provided to us by our Senior Student Nurse (Project Leader)
were located via online research using CINAHL(EBSCO), MEDLINE (Ovid), PubMED
(OHSU) & Nursing Reference Center:
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Inclusion criteria: When should hypothermia be initiated and for which patients?
 Cardiac arrest
 Comatose
 Within 6 hours of arrest
Exclusion criteria: Which patients should not get hypothermia therapy?
 Head trauma
 Overdose
Adverse effects/prevention
 Sedation/shivering prevention
 Electrolyte imbalances
 Hyperglycemia
 Cardiovascular/hemodynamic effects
Positive effects
 Neurological outcomes
 Statistics
 Decreased metabolism
 Decrease in excitatory amino acids
 Suppresses inflammatory response
 Decreases free radical production
 Prevention of apoptosis
The located articles where first given a rating of strength for the evidence, based on this evidenceleveling hierarchy provided to us by our Project Leader which she retrieved from the American
Association of Critical Care Nurses (American Journal of Critical Care)
First, the articles were critiqued with the following
topics provided by our Project Leader:
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Sample size
Research Methods
Findings
Study Limitations
* These articles were then synthesized to provide preliminary
recommendations to our Project Leader as she prepared to
present to information to a Salem Hospital EBP meeting.
Second, the articles were critiqued with the following topics
provided by our Instructor:
 Qualifications of author(s)
 Quality of the source
 Currency of the work
 Evidence that suggests bias
 Methods used to generate information or source from
which information was obtained
 Primary findings, suggestions and/or recommendations
& extent to how they are supported by the information
previously presented
 Overall quality of the document as compared to other
sources
 Original contribution the article makes to the field of
nursing knowledge and/or to our nursing practice
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Next the findings suggestions, and/or
recommendations that were well-supported in
the evidence where identified.
These findings suggestions, and/or
recommendations were then synthesized into
coherent statements that a clinician could
incorporate into his/her practice.
Statements were then qualified by the strength
of the evidence supporting them.
Team Response
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Extensive worldwide evidence has
demonstrated that early
implementation of TH, reduces
mortality and leads to better
neurological outcomes for patients
with return of spontaneous
circulation (ROSC) post cardiac
arrest while they were comatose.
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Even a stronger recommendation
now exists to implement TH early
in ROSC post cardiac arrest as the
AHA has included TH as an option
in their 2010 Guidelines for
Cardiopulmonary Resuscitation &
Emergency Cardiovascular Care.
The recommendation from the EBP
research team is therefore is to start
therapeutic hypothermia
immediately after ROSC following
cardiac arrest in the ED (or prehospital care if on radio control of
EMS), for all patients that remain
comatose and who do not meet
certain exclusion categories.
Team response
NOT LIKE THIS
MORE LIKE THIS
Excerpts from recently approved policy following
presentation of recommendations from our
Project Leader to SH EPB Staff:
Steps & Key Points
I – Identification of Eligible Patients
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Emergency Department physicians, and nurses
evaluate for treatment eligibility in collaboration
with cardiology, critical care intensivists,
neurology and neurosurgery
INCLUSION CRITERIA
A.
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Cardiac arrest with ROSC
Neurological status is unresponsive after
ROSC (GCS <8)
MAP maintained at least 60mmHg
spontaneous or with fluids/pressors
Time from initiation of hypothermia is less
than 6 hours after ROSC
EXCLUSION CRITERIA
B.
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Hypotension (MAP< 60 mmHg for more
than 30 minutes after return of spontaneous
circulation with the use of fluids/pressors)
Conflict with DNR/Advanced Directive
Sepsis as suspected cause of cardiac arrest
Uncontrolled bleeding: Should be controlled
before initiating therapeutic hypothermia
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INITIATE COOLING AS SOON AS
POSSIBLE. COOLING CAN BE
INITATED UP TO SIX HOURS POST
EVENT.
DO NOT DELAY CARDIAC CARE TO
INITIATE COOLING.
A.
B.
C.
Emergency department must continue
therapeutic hypothermia if EMS initiates
treatment in the field if emergency department
physician determines eligibility per hospital
protocol (See Identification of Eligible Patients, I)
Emergency Department physician must
determine eligibility and initiate hypothermia as
soon as possible if EMS has not initiated
hypothermia. (See Procedure for induction and
maintenance of cooling, III)
Cooling must be continued in the cardiac
procedural lab.
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MAINTAIN TEMPERATURE
BETWEEN 32-34 DEGREES CELSIUS.
AVOID OVER COOLING.
Emergency Department
i. Obtain baseline CBC, CMP, Magnesium,
Phosphate, Cardiac enzymes, DIC Panel
Vital Signs and neurologic signs as
directed by physician
ii. Foley catheter placement with
temperature probe. (Oesophageal/ventral
venous temperature better reflects core
temperature, especially with rapid
cooling.
A.
iii.
iv.
v.
Notify Critical Care charge nurses early of
eligible hypothermia therapy patients
Administer analgesia, sedation, paralytics,
shivering agents as directed
Wrap hands and feet with dry towels to
decrease shivering stimulus
vi.
vii.
Administer bolus of 30ml/kg (not
exceeding 2 Liters) of 1-4 degree Celsius
Normal Saline/Lactated Ringers in
Second IV site over 30 minutes. Limit IV
fluids with dextrose, or control blood
sugar with insulin. Consider hypertonic
fluid to limit extravasation.
Place surface cooling blankets until
endovascular catheter placement is
possible
viii. Place
ix.
x.
ice packs on axilla, groin and neck
until endovascular placement is possible.
Endovascular cooling: Physicians and
nurses trained and competent in
endovascular cooling must be present
when this method is selected. Follow
manufacturers guidelines.
Monitor the skin carefully
Metabolic Effects – While most metabolic effects
will be more apparent during ICU, some may
present during the initial induction process done in
the ED:
A.
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Potassium: Hypothermia commonly causes
hypokalemia, which may be exacerbated by insulin
administration.
Glucose: Hypothermia causes insulin resistance
resulting in hyperglycemia. Blood glucose monitoring
may be required hourly. Arterial/central catheter
blood may be more accurate than fingersticks due to
vasoconstriction in extremities.
Drug Clearance: Hypothermia decreases drug
metabolism. Titrate accordingly.
B.
Cardiovascular/Hemodynamics
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Blood Pressure: Vasoconstriction may occur during
cooling. monitor blood pressure frequently, set a target
MAP with the team dependant upon patient
circumstances.
Heart Rate: Hypothermia can induce initial tachycardia
followed by bradycardia.
Arrhythmias: Risk increases as temperature drops.
AVOID OVERCOOLING.
Cardiac Output: CO will decrease. Usually supply
equals demand due to metabolism reduction.
Electrocardiogram: Prolonged PR intervals, increased
QT interval, and widening of the QRS complex.
Coagulation: Mild hypothermia can induce mild
coagulopathy.
Any questions?