JEFFERSON REGIONAL MEDICAL CENTER
PATIENT CARE SERVICES DIVISION
POLICY MANUAL
ER, Cath Lab, ICU, CVU
Subject
Therapeutic Hypothermia
Post Cardiac Arrest
Policy Number
60.1.87
Series Number
60
Series Category
Clinical Functions
I.
GENERAL PROVISIONS
A.
Policy Objectives:
The objective of this policy is to optimize the care of comatose cardiac
arrest survivors.
B.
Purpose:
Patients ordered post cardiac arrest therapeutic hypothermia will have
nursing care provided according to the following policy and procedure.
C.
Scope of Coverage:
Registered Nurses working in the Emergency Department, the Cardiac
Cath Lab, ICU and CVU, in which use of the post cardiac arrest
therapeutic hypothermia protocol is approved by the Medical Directors of
those departments.
D.
Authority:
The Vice President and Chief Nursing Officer is the administrator
responsible for interpretation and implementation of this policy and
procedure.
II.
POLICY AND PROCEDURE
A.
Therapeutic Hypothermia is defined as patient cooling to 32º - 34ºC of
surviving comatose, post cardiac arrest patients in an attempt to optimize
cardiopulmonary function and systemic perfusion especially to the brain
and help to improve long term neurologically intact survival.
Therapeutic Hypothermia Post Cardiac Arrest
Page 2
B.
Inclusion Criteria:
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C.
Comatose non traumatic cardiac arrest survivors on ventilator with
return of spontaneous circulation and Glasgow Coma Motor Score
<6 pre sedation
Age >18years
Pre arrest cognitive status not severely impaired (i.e. performed
ADL independently)
No other obvious reason for coma and ROSC (Return of
Spontaneous Circulation) was within 60 minutes of cardiac arrest
Patient has ROSC to a systolic BP of >90 with or without
vasoactive drugs
Patient does not have a code status prohibiting resuscitation
Temperature after ROSC is >34ºC
Time to initiation of hypothermia is less than 6 hours
Hemodynamically stable with no evidence of uncontrolled
dysrhythmias
No existing, multi system organ dysfunction, severe sepsis, or
comorbidities with minimal chance or meaningful survival
independent of neurological status
Exclusion Criteria
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Uncontrolled GI bleeding
Presence of Advance Directive or Code Status prohibiting
resuscitation
Recent major surgery within 14 days (hypothermia may increase
the risk of infection and bleeding)
Systemic infection / sepsis as hypothermia may inhibit immune
function and is associated with a small increase in risk of infection
Patients in a coma from other causes (drug intoxication, preexisting
coma prior to arrest, head trauma, stroke)
Trauma
Pregnancy in third trimester
Temperature of <30ºC following arrest
Known or preexisting coagulopathy
Absence of need for mechanical ventilation as a part of the
resuscitative effort
Patients who have a known pre arrest terminal illness
Patients who are alert and oriented following the initial arrest
Refractory hypotension <90systolic BP with pressors
Not indicated for patients with isolated respiratory arrest
Therapeutic Hypothermia Post Cardiac Arrest
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D.
Effects of Therapeutic Hypothermia
Temperature Conversion Table
Celsius
Fahrenheit
38.0
100.4
37.0
98.6
36.0
96.8
35.0
95
34.0
93.2
33.0
91.4
32.0
89.6
31.0
87.8
30.0
86
1.
Brain temperature during the first 24 hours after resuscitation from
cardiac arrest may have a significant effect on survival and
neurological recovery. Cooling to 32º-34ºC for 24 hours may
decrease chance of death and increase the chance of neurological
recovery.
2.
Hypothermia activates the sympathetic nervous system causing
vasoconstriction and shivering. Shivering increases oxygen
consumption by 40-100%. Sedatives, opiates, and neuromuscular
blockers can counteract these responses and enhance the
effectiveness of active cooling. However, initiating paralysis in a
patient that is already hypothermic should be avoided because it
can result in a precipitous drop in core body temperature. Elderly
patients will cool more quickly than younger or obese patients.
3.
Hypothermia initially causes sinus tachycardia, then bradycardia. It
is extremely important to keep temp >32ºC. <32º, increased risk for
arrhythmias and <28ºC increased risk for ventricular fibrillation.
4.
Hypothermia shifts the oxyhemoglobin curve to the left and may
result in decreased oxygen delivery. However, the metabolic rate is
also lowered, decreasing oxygen consumption and carbon dioxide
production. Ventilator settings should be adjusted due to
decreased CO2 production, using temperature corrected blood
gases.
5.
Hypothermia decreases cardiac output and increases systemic
vascular resistance
Therapeutic Hypothermia Post Cardiac Arrest
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6.
Hypothermia can induce coagulopathy, which is treatable with
platelets and FFP.
7.
Hypothermia induced diuresis is to be expected and should be
treated aggressively with fluid and electrolyte repletion.
Magnesium, phosphorus and potassium should be monitored
closely and maintained in the normal range as a rebound to a
higher range can occur with re warming.
8.
Decreased insulin secretion and sensitivity leads to hyperglycemia,
which should be treated aggressively
9.
Re warming must proceed slowly to prevent vasodilation,
hypotension, and rapid fluid and electrolyte shifts.
Potential Lab Anormalities Associated with Hypothermia
Potential lab abnormality
Increased amylase
Increased LFT’S
Increased serum glucose
Decreased K, Mg, Phos, Ca
Increased lactate
Metabolic acidosis
Thrombocytepenia
Leukopenia
Increased PT/PTT
E.
Treatment
No intervention unless persistent after
rewarming
No intervention unless persistent after
rewarming
Follow insulin protocol
Correct as needed
Optimize oxygen delivery
Optimize oxygen delivery
Correct if active bleeding
No intervention unless persistent after
rewarming
Correct if active bleeding
Initiation of TH following out of hospital arrest where cooling initiated pre
hospital or initiated in the ER:
1.
Continue prehospital cooling until cooling is initiated in the ED.
2.
Pre Procedure:
a.
Review eligibility, contraindications, advance directives and
overall prognosis. Provide family an explanation of the
purpose of hypothermia and the need for pharmacologic
paralysis.
b.
Obtain order from physician using TH protocol order sheet.
Physician to indicate internal or external cooling method.
Therapeutic Hypothermia Post Cardiac Arrest
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Procedure can be ordered by Emergency Physicians,
Cardiologist, Cardiac Surgery, or Critical Care Physicians
only.
c.
Exclude other causes of coma and document Glasgow
Coma Motor Score (See attached)
d.
Obtain the following lab tests stat:
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ABG with ionized calcium
CBC, PT/INR, PTT, Fibrinogen
Comprehensive Metabolic Panel (Magnesium and
phosphorous)
Lactate
CPK-MB and Troponin
Cortisol Level
Urinalysis
Amylase and Lipase
Urine HCG if female <50
e.
Chest X-Ray and EKG
f.
If cardiac cath is indicated, hypothermia should not be
delayed. Patient will be transported to cath lab with cooling
apparel on and patient will be connected to hypothermia
machine in cath lab so that cooling can continue during
procedure. If patient for cardiac cath use left groin for
catheter insertion.
g.
Assist physician with insertion of arterial line and central
venous catheter BEFORE cooling. Use femoral site for CVP
catheter in case patient needs cold saline infusion to assist
with decreasing temperature as the safety of infusing cold
saline through the jugular or subclavian site is not yet known
h.
Place temperature probe indwelling bladder catheter.
Protect indwelling catheter and temperature probe from
coming into contact with cooling blanket.
i.
Thorough skin assessment prior to applying cooling system
wraps.
j.
Obtain Cincinnati Sub Zero Hypothermia Machine and Kool
Kit.
Therapeutic Hypothermia Post Cardiac Arrest
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2.
k.
Connect the head wrap, vest, and lower body blanket to the
hypothermia machine and pre-fill prior to placing on patient.
Set patient temperature to 33ºC and depress auto control
button. Ensure that cooling blanket in and out flow tracts are
unobstructed and that fluid is filling wraps when machine is
turned on. You may need to add more water to the device.
l.
If utilizing central cooling, obtain the Alsius Coolgard
machine, ICY femoral catheter, 500cc bag of sterile NSS
(not 1000cc), and Alsius CG start up kit. Follow quick set
up process. Attempt to pre cool system to maximize the
initial patient cooling rate. Set target temp to 33ºC and rate
at MAX power.
m.
Sedate patient per physician order and maintain sedation
scale of 0-1. Do not perform daily awakening and sedation
discontinuation on therapeutic hypothermia patients.
Settings:
a.
b.
c.
3.
Initially set to cooling automatic mode, and set point patient
temp to 33ºC if using external cooling machine. Also set
target temperature of 33ºC if utilizing internal cooling
machine.
Maintain at 32º - 34ºC for 24 hours after cooling initiated.
Never allow patient temperature to drop below 32ºC.
Monitoring:
a.
Monitor patient temperature continuously utilizing rectal
probe for therapeutic hypothermia machine and temperature
sensing foley. Must have rectal probe in place for external
cooling device to function properly in addition to the
temperature sensing foley. Document hourly patient
temperature on flow sheet. Also document water
temperature on external device and patient temperature
setting hourly on both devices.
b.
If utilizing internal cooling device may use one temperature
source but must be temperature sensing foley.
c.
Continuous cardiac monitor. Keep defibrillator at bedside
during entire process.
d.
Do not use warm humidification on the ventilator during the
period of therapeutic hypothermia or during rewarming.
Therapeutic Hypothermia Post Cardiac Arrest
Page 7
e.
Continuous pulse oximetry and document hourly
f.
Document hourly Bedside Shivering Assessment Scale
g.
Maintain MAP (mean arterial pressure 65-120)
h.
Document vital signs and rhythm hourly or more frequently if
patient condition dictates.
i.
Document hourly urine output (Hypothermia induced
diuresis is common and IV fluid resuscitation may be
required)
j.
Obtain temperature corrected ABG every 6 hours or as
needed.
k.
RBG every 6 hours ( may require more frequent monitoring
when cooled)
l.
CPK-MB and Troponin 6 hours after target temperature
achieved
m.
CBC, Platelets, PT/INR, PTT, Electrolytes, BUN, Cr, Ca, Mg,
PO4 and lactate level every 6 hours X4
n.
Saline gauze patches to eyes and frequent eye care.
Reposition every 2 hours and perform skin assessment for
thermal injury every 4 hours.
o.
Notify ordering physician if patient develops shivering or
seizures. Keep patient sedated to Sedation Scale of 0-1 to
prevent shivering and seizures. Document hourly bedside
shivering assessment scale.
p.
If target temperature not reached within 4 hours notify
physician. Add ice packs to groin and axilla and consider
additional bolus of cold NSS (500ml cooled to 4ºC.) over 10
minutes.
q.
Avoid temperature shifts if at all possible.
r.
Maintain cooling for 24 hours unless patients develops any
of the complications that are indication for discontinuation of
therapy. (See order set for criteria to stop therapeutic
hypothermia)
Therapeutic Hypothermia Post Cardiac Arrest
Page 8
s.
F.
Do not provide nutrition to the patient during the initiation,
maintenance or rewarming phases of therapy.
Induction of TH following in hospital cardiac arrest
1.
Pre Procedure:
a.
Review eligibility, contraindications, advance directives and
overall prognosis.
b.
Obtain order from physician using TH protocol order sheet.
Physician must indicate which method, internal or external,
to use. Must be ordered by ER physician, cardiologist,
cardiac surgeon, or critical care physician only.
c.
Exclude other causes of coma and document Glasgow
Coma Motor Score . (See attached.)
d.
Obtain the following lab tests stat:








ABG with ionized calcium
CBC, PT/INR, PTT, Fibrinogen
Comprehensive Metabolic Panel (Magnesium and
phosphorous)
Lactate
CPK-MB and Troponin
Cortisol Level
Urinalysis
Amylase and Lipase
e.
Chest X-Ray and EKG
f.
Head CT to rule out intracranial hemorrhage if deemed
medically necessary
g.
Consult cardiologist of attending choice if not already on
service. If cardiac cath is indicated, hypothermia should not
be delayed. Patient will be transported to cath lab with
cooling apparel on and patient will be connected to
hypothermia machine in cath lab so that cooling can
continue during procedure. Utilize left groin for catheter
insertion
h.
Assist physician with insertion of arterial line and central
venous catheter BEFORE cooling. Use femoral site for CVP
Therapeutic Hypothermia Post Cardiac Arrest
Page 9
catheter in case patient needs cold saline infusion to assist
with decreasing temperature as the safety of infusing cold
saline through the jugular or subclavian site is not yet known
2.
i.
Place temperature probe indwelling bladder catheter.
Protect indwelling catheter and temperature probe from
coming into contact with cooling blanket.
j.
Thorough skin assessment prior to applying cooling system
wraps.
k.
Obtain Cincinnati Sub Zero Hypothermia Machine and Kool
Kit.
l.
Connect the head wrap, vest, and lower body blanket to the
hypothermia machine and pre-fill prior to placing on patient.
Set patient temperature to 33ºC and depress auto control
button. Ensure that cooling blanket in and out flow tracts are
unobstructed and that fluid is filling wraps when machine is
turned on. You may need to add more water to the device.
m.
If utilizing central cooling, obtain the Alsius Coolgard
machine, ICY catheter for femoral insertion, 500cc bag of
sterile NSS (not 1000cc), and Alsius CG start up kit. Follow
quick set up process. Attempt to pre cool the system to
maximize the initial patient cooling rate. Set target
temperature to 33ºC and rate at MAX power.
n.
Sedate patient per physician order and maintain sedation
scale of 0-1. Do not perform daily awakening and sedation
discontinuation on therapeutic hypothermia patients.
Settings:
a.
Initially set to cooling automatic mode, and set point patient
temp to 33ºC if using external cooling machine. Also set
target temperature of 33ºC if utilizing internal cooling
machine.
b.
Maintain at 32º - 34ºC for 24 hours after cooling initiated.
c.
Never allow patient temperature to drop below 32ºC.
Therapeutic Hypothermia Post Cardiac Arrest
Page 10
3.
Monitoring:
a.
Monitor patient temperature continuously utilizing rectal
probe for therapeutic hypothermia machine and temperature
sensing foley. Must have rectal probe in place for external
cooling device to function properly in addition to the
temperature sensing foley. Document hourly patient
temperature on flow sheet. Also document water
temperature hourly when utilizing external cooling and
temperature setting hourly on both devices.
b.
If utilizing internal cooling device may use one temperature
source but must be temperature sensing foley.
c.
Continuous cardiac monitor. Keep defibrillator at bedside
during entire process.
d.
Continuous end tidal CO2 monitoring while on vent and
document hourly
e.
PCO2 should be maintained between 35-45mm Hg.
f.
Do not use warm humidification on the ventilator during the
period of therapeutic hypothermia or during rewarming.
g.
Continuous pulse oximetry and document hourly
h.
Document hourly Bedside Shivering Assessment Scale
i.
Maintain MAP (mean arterial pressure) 65-120
j.
Continuous CVP monitoring and document hourly. A
minimum CVP of > 8 is a reasonable target. All CVP
readings should be obtained with the patient in the flat
position.
k.
Document vital signs and rhythm hourly or more frequently if
patient condition dictates.
l.
Document hourly urine output (Hypothermia induced
diuresis is common and IV fluid resuscitation may be
required)
m.
Obtain temperature corrected ABG every 6 hours or as
needed.
Therapeutic Hypothermia Post Cardiac Arrest
Page 11
n.
RBG every 6 hours (may require more frequent monitoring
when cooled)
o.
CPK-MB and Troponin 6 hours after target temperature
achieved
p.
CBC, Platelets, PT/INR, PTT, Electrolytes, BUN, Cr, Ca, Mg,
PO4 and lactate level every 6 hours X4
q.
Saline gauze patches to eyes and frequent eye care.
Reposition every 2 hours and perform skin assessment for
thermal injury every 4 hours.
r.
Notify ordering physician if patient develops shivering or
seizures. Keep patient sedated to Sedation Scale of 0-1 to
prevent shivering and seizures.
s.
If target temperature not reached within 4 hours notify
physician. Add ice packs to groin and axilla and consider
additional bolus of cold NSS (500cc cooled to 4ºC.) over 10
minutes.
t.
Avoid temperature shifts if at all possible.
u.
Maintain cooling for 24 hours. Discontinue therapeutic
hypothermia for any of the following:
v.
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
Ventricular tachycardia or fibrillation
Asystole
Sustained supraventricular tachycardia
Refractory hypotension (defined by the need for more
than 2 pressors

Suspected sepsis
Do not provide nutrition to the patient during the initiation,
maintenance or rewarming phases of therapy.
G.
Rewarming:
1.
Begin 24 hours after cooling initiated NOT 24 hours after target
temperature achieved.
2.
Rewarming must be done slowly over 10-12 hours. Goal of
rewarming is 0.25ºC per hour. Rewarming too rapidly can cause
Therapeutic Hypothermia Post Cardiac Arrest
Page 12
vasodilatation, hypotension, and rapid electrolyte shifts. To avoid
complications prior to rewarming:


H.
Volume load with NSS to compensate for reductions in blood
pressure, and CVP if needed.
Potassium shifts to extracellular compartment during
rewarming. Stop all potassium containing fluids, however,
always correct hypokalemia, and other electrolytes, to the
normal range. Monitor potassium level every 4 hours during
rewarming.
3.
Continue hourly monitoring of all parameters until temperature
36.5ºC, then routine ICU / CVU vitals.
4.
Monitor temperature corrected ABG every 2 hours during
rewarming.
5.
If patient paralyzed, maintain paralysis until patient reaches 36ºC.
6.
Discontinue active rewarming when patient temperature reaches
36.5ºC. Keep on hypothermia machine or Cool Gurard for at least
24 hours post rewarming to maintain normothermia.
7.
Monitor RBG every 2 hours during rewarming as insulin resistance
resolves and patient at increased risk for hypoglycemia
Management of Shivering:
Bedside Shivering Assessment Scale
Score
Definition
0
None, no shivering noted on palpation of the
masseter, neck, or chest wall
1
Mild, shivering localized to the neck and / or
thorax only
2
Moderate, shivering involves gross movement
of the upper extremities (in addition to the neck
and thorax)
3
Severe, shivering involves gross movements of
the trunk and upper and lower extremities
1.
Observe for shivering and document hourly.
2.
May apply warm blankets to the feet and hands
3.
Follow medication protocol orders for shivering. May need to start
neuromuscular blockade if ineffective.
Therapeutic Hypothermia Post Cardiac Arrest
Page 13
REFERENCES:
Hypothermia after Cardiac Arrest Study Group (2002). Mild Therapeutic Hypothermia to
improve the Neurologic Outcome After Cardiac Arrest. New England Journal of
Medicine, 346(8): 549-556
Bernard SA, Gray, TW, Buist MD, et al. (2002). Treatment of Comatose Survivors of
Out of Hospital Cardiac Arrest with Induced Hypothermia. New England Journal of
Medicine, 346 (8): 557-563
Sagalyn, Emily et al. (2009). Therapeutic Hypothermia after cardiac arrest in clinical
practice: Review and compilation of recent experiences. Critical Care Medicine,
Volume 37, S223-227.
Seder, D. M.D., Van der Kloot, T., M.D. (2009). Methods of cooling: Practical aspects
of therapeutic temperature management. Critical Care Medicine, Volume 37, S211-219.
Vice President & Chief
Title Nursing Officer
Signed
Original Date
Revision Date(s)
1/10
Therapeutic Hypothermia Post Cardiac Arrest
Page 14
ATTACHMENT 1
Glasgow Coma Scale
Eye opening
response
Verbal Response
Motor Response
Spontaneous open with blinking at baseline
4
Opens to verbal command, speech or shout
3
Opens to pain, not applied to face
2
None
1
Oriented
5
Confused conversation, but able to answer
questions
4
Inappropriate responses, words discernible
3
Incomprehensible speech
2
None
1
Obeys commands for movements
6
Purposeful movement to painful stimuli
5
Withdraws from pain
4
Abnormal (spastic) flexion, decorticate
posture
3
Extensor (rigid) response, decerebrate
Posture
2
None
1