Good Samaritan Hospital Hypothermia Therapy :A New Frontier in Reducing Morbidity and Mortality in the

Post-Cardiac Arrest Patient

Missi Chittum RN, BSNVickie Wolnitzek RN, BSN

• Sudden cardiac arrest (SCA) is a leading cause of death in the US

• Approximately 295,000 US out-of-hospital arrest per year• Less than 10% of people who present to the hospital survive

to discharge• Up to 65% initially comatose survivors suffer debilitating

neurological outcomes  

Roger VL,Go AS, Lloyd-James DM, et al. Heart disease and stroke statistics-2011 update: a report from the American Heart Association Statistics . CIRCULATION. 2011:123(4)c18-c209.

Scope of the Problem:

What is Mild Therapeutic Hypothermia?

• Clinically induced hypothermia 32-34 degrees for 12-24 hours within 4 to 8 hours of spontaneous circulation (ROSC)

• Evidence based care• Brain-protective treatment to prevent/reduce reperfusion

injury following cardiac arrest and return of circulation• Improves chance for good neurological outcome

AHA Guidelines for Cardiopulmonary Resuscitation and Emergency CV Care. Part 9. CIRCULATION 2010

History of Therapeutic Hypothermia

• 1950s: First described but with no formal testing• 1960s: Temperature targets were 28-32°C and research

                    findings were not favorable • 1980s: Revival of interest using dogs after cardiac

arrest   with temperature targets of 32-34°C had positive   outcomes

• 1990s: Therapeutic hypothermia was revisited: Can we safely cool patients? What is the best cooling method?

• 2000s: Using evidence based practice from prior                    research trials                  

Evidence Based Research:

1. Dr. Bernard’ s study- one of the first

2. Mauro Oddo study –appropriate temperature range

3. HACA- a larger group of people with positive     outcomes

4. Sebastian Wolfrum- showed it was possible to Hypothermia Therapy along side PCI despite the higher risk of bleeding with anticoagulants

Dr. Bernard’s Study

• European study• Decrease in mortality and

      improved neurological outcomes• 77 patients

        - 43 hypothermia        - 34 normothermia• Results

         -49% of hypothermic patients had good outcomes           compared to 26% normothermic patients

    

  Bernard SA, et al. “Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia.” NEJM 2002; 346 (8): 546-556. 

Mauro Oddo:• Researcher Mauro Oddo• Implementation Study

109 comatose out of hospital arrests Retrospective Determined feasibility of Therapeutic Hypothermia

(TH) to 33 degrees C in clinical practice VF as initial rhythm Good outcomes: TH 56% , standard care 26%

• TH safely applied to patients with initial rhythm of PEA and asystole. Outcomes were poor, though the subset was small

Oddo M. et al. from evidence to clinical practice : Effective implementation of therapeutic hypothermia to improve patient outcome after cardiac arrest. Critical Care Medicine 2006: 34 (7): 1865-1873

HACA Study (Hypothermia After Cardiac Arrest)

Multi-center trial• 275 patients- 137 Hypothermia- 138 Normothermia

Results- 55% Hypothermia group favorable outcome- 39% Normothermia group favorable outcome   

The Hypothermia After Cardiac Arrest Study Group. “Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest.” NEJM 2002 ; 346 (8): 549-556.

Wolfrum German Study• Objective: Is it feasible, safe, and beneficial to combine

hypothermia therapy with percutaneous intervention(PCI)?

• Patients: 33 cardiac arrest w/ v-fib, ROSC, unconscious , and with acute ST elevation MI (STEMI)

• Results: 1.Did not result in longer door-to-balloon times2.Target temp was reached w/i 4 hours3.No increase in bleeding complications &

infections4.Trend toward lower mortality (25% vs 35%)5.Improved neurologic outcome

AHA 2010 Post Arrest Guidelines

1. Post VF arrest patients who are unresponsive with a ROSC after 0ut-of-hospital cardiac arrest should be cooled to:

1.32 ° C to 34 °C2.Duration of 12-24 hours

2. Therapeutic Hypothermia (TH) may also be considered for comatose adult patients with ROSC after initial rhythm is

PEA or asystole3. Therapeutic Hypothermia can be considered for in-hospital

arrests 4. Transport patients to appropriate hospitals that can manage and implement post cardiac arrest care to include TH  

AHA Guidelines for Cardiopulmonary Resuscitation and Emergency CV Care. Part 9. CIRCULATION 2010

Pathophysiology…

• Cardiac arrest = No blood flow to the brain• Depletes brain O2 stores within 20 seconds• Results in irreversible brain damage if circulation is not

restored. • Research has proven that it is not the lack of oxygen

during the arrest that causes brain death, yet it is the release of oxygen free radicals into the brain that causes post cardiac arrest brain injury when circulation is restored

More Pathophysiology…

Benefits of Therapeutic Induced Hypothermia

• Cerebral metabolism will decrease by 5%-7%for every 1° C reduction in core body temperature (Oku et al.,1993)

• Reduces intercellular acidosis

• Decreases the inflammatory response and cytokines release

• Protects the blood brain lipomembranes

Complications of Therapeutic Hypothermia

• Depressed myocardial function• Dysrhythmias• Coagulopathy• Immunosupression• Fluid and electrolyte imbalances• Slow drug metabolism

Inclusion Criteria• Post cardiac arrest

(VF/pulseless VT)• Witnessed arrest• Time of collapse to

ROSC <30 minutes• Initiation of therapy within

6 hours of arrest time

• Initial temperature > 30 degrees C

• No command following• NO level of brain death

precludes cooling

Exclusion Criteria• DNR, terminal illness,

poor baseline function• Hemorrhagic CVA, status

epilepticus• Active severe bleeding• Trauma until ruled out

• MAP < 60 mmHg for > 30 mins and requiring > 1 pressor

• Uncontrolled cardiac arrhythmias

• History of Cryoglobulinemia

• Pregnacy

The most important exclusion to remember is…

Don’t chill the awake and talking patient!

Please don’t freezeme!!!

Key Clinical Priorities: Pre-Induction Phase

(Time Sensitive)• Confirm witnessed v-fib arrest• EMS-consider transporting patient to hospital with

hypothermia therapy• Determine ROSC time• Patient not responsive and following commands• Initiate cooling- mechanism dependent on where patient is• EKG – AMI requiring PCI• Record Glasgow Coma score

Key Clinical Priorities:Induction Phase

• Head CT• Record an initial temperature- rectal the best• Central line placement• Continue cooling method• Baseline labs• Initiate sedation/paralytic meds• Shivering • Transfer to appropriate critical care unit

Key Clinical Priorities:Maintenance Phase

• Focus on cardiac & cerebral resuscitation• Nursing care 1:1• Maintain existing cooling methods• Use hospital approved cooling method and temperature

monitoring device• Monitor patient for side effects and complications

Importance of Rewarming Phase…

• Rewarming should occur at 0.3 to 0.5 °Celsius per hour • Avoid complications of rapid rewarming, i.e. dangerous

electrolyte shifts and rebound hyperthermia• Monitor lab values: K+ will increase & glucose decrease• Discontinue sedation and paralytics once goal temp is

achieved

Physiologic Effects of Hypothermia Therapy by

Body Systems

Cardiovascular

• Ventricular arrhythmias- atrial and ventricular fibrillation• Myocardial depression, bradycardia, AV block• Increased SVR, decreased CO, decreased contractility

Respiratory• Decreased RR• Hypoventilation• Suppression of cough and mucociliary reflexes from

hypothermia therapy may lead to hypoxemia, atelectasis, and pneumonia

• Shift in oxyhemoglobin dissociation curve to the left (less oxygen is released from oxyhemoglobin to the soft tissues)

Metabolic

• Hypothermia will cause glucose levels to elevate • When shivering is allowed, there is an increase in

glucose utilization and levels then can remain NORMAL• Yet shivering increases the metabolic rate, CO2

production and O2 consumption and myocardial work• Slowed drug metabolism

Gastrointestinal• Decreased motility, liver function, • Ileus• Stress Ulceration

Renal• ↑ urine output• ↑ loss of electrolytes• ↓ creatinine clearance• Tubular dysfunction

Electrolyte Shifts• Find graph/picture

Hematologic• Increased blood viscosity (hemoconcentration)• Platelet dysfunction

Cooling methods…

• Initiate quickly as possible w/ goal to reach temperature 6 hours after ROSC

• Goal: 33°C / 91.4°F• Period of 24 hours once goal temp is achieved

Cooling Methods

• Surface cooling with ice packs• Surface cooling with cooling blanket• Cool room• Fan• Moist towels and exposed skin• Use your hospital approved

cooling device

Other Methods of Cooling:• Internal cooling with infusion of cool IV fluids• Internal cooling with gastric lavage of iced saline

Cooling Blankets:

Cooling Blanket

Thermo regulates to preset patient goal temperature 33° C with the use of a rectal or esophageal probe

Cooling Method: Endovascular Device

Core Cooling Methods

Pharmacological Agents for Prevention of Shivering

Nursing Care

Interdisciplinary Collaboration• Champions• Pre-hospital care• ER• Cath Lab• Intensivists• Cardiologists• Pharmacy• Critical Care Units• Family

Lessons Learned

Starting a Program

Usman Omar.8 Key Principes for Success. Muslim Strategic Initiative 2011

Successes

What Does The Future Hold?

1. Research using the new sophisticated internal and external cooling devices

2. Increased research to determine the optimal time to target temperature and the rates of cooling and rewarming

3. Future advances will require earlier initiation of therapy either prior to cardiac arrest or during CPR

4. Hydrogen sulfide to induce a hibernation-like state in animals seems to hold promise

    

Concluding Thoughts…• Studies have shown that only 6 patients need to receive

therapeutic hypothermia for 1 life to be saved.

• The ONLY supportive therapy for favorable neurological outcomes after an arrest

• The faster hypothermia therapy is induced, the better the outcomes

• Cool them down instead of warm them up

Hypothermia Therapy:

COOL MEDICINE… Are you doing it?

ReferencesBernard SA, Gray TW, Buist MD, Jones BM, Silvester W, Gutteridge G, Smith K. Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia. N Eng J Med 2002; 346(8):557-563.

Nair SU, Lundbye JB. The use of hypothermia therapy in cardiac arrest survivors. Therapeutic Hypothermia and Temperature Management 2011; 1(1):9-21.

Hypothermia after Cardiac Arrest Study Group. Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest. N Eng J Med, Feb 21 2002. 346(8): p. 549-56.

Peberdy MA, Callaway CS, Neumar RW, et al. Part 9:post-cardiac arrest care: 2010 American Heart Association Guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2010; 122(18 supp 3):S768-S786.

Polderman KH. Mechanisms of action, physiological effects, and complications of hypothermia. Crit Care Med. 2009; 37(supp 7):S186-S202.

Harden J. Take a cool look at therapeutic hypothermia. Nursing 2011. 2011;41(9):p 46-51.

Oddo M, Schaller MD, Feihl F, Ribordy V, Liaudet L. From evidence to clinical practice: effective implementation of therapeutic hypothermia to improve patient outcome after cardiac arrest. Crit Care Med. 2006 Jul; 34(7):1865-73.

Roger VL, Go AS, Lloyd-Jones DM, et al. Heart disease and stroke statistics-2011 update: a report from the American Heart Association Statistics. Circulation. 2011; 123(4):c18-c209.

Bahrt G. Cooler heart, better odds: Induced hypothermia. Nursing Management. 2009 Jul; 40(7):22-29.

Oku K, Sterz F, Safar P, Johnson D, Obrist W, Leonov Y, Kuboyama K, Tisherman SA, Stezoski SW. Mild hypothermia after cardiac arrest in dogs does not affect postarrest multifocal cerebral hypoperfusion. Stroke 1993:24:1590-1597

Hypothermia cooling techniques. Resuscitation Central. Online 12 November 2011.

Wolfrum S. Pieerau C, Radke PW, Schnkert H, Kurowski V. Mild therapeutic hypothermia in patients after out of hospital cardiac arrest due to accute ST elevation myocardial infarction undergoing immediate percutaneous coronary interventionCrit Care Med 2008 Jun;36(6):1780-6