1. Part 1 Union Hospital, Inc. Emergency Department

2. In the Media Newsweek July 2007 New York Times Dec 2008

3. Historical Perspective of Hypothermia Hypothermia for clinical purposes has ancient roots, used by Egyptians, Greeks, and Romans Hippocrates advocated packing wounded patients in snow and ice to reduce hemorrhage 1950’s Hypothermia was utilized for intracranial aneurysm clipping and for cardiac surgery during circulatory arrest 1960’s Clinical trials with hypothermia (30 degrees Celsius or lower) were discontinued because of the side effects, uncertain benefits, and management problems

4. Historical Perspective of Hypothermia 1980’s Animal studies showed benefits of mild (32-35 degrees Celsius) hypothermia rather than moderate or deep hypothermia (less severe side effects) 1997 first human study by Dr. Bernard with mild hypothermia Two landmark studies in 2002. 55% in the hypothermia group had favorable neurologic outcome within six months compared to 39% in normothermic group. 49% hypothermia vs 29% normothermia DC to home or rehab

5. Recommendations 2010 ILCOR (2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations) 2010 AHA guidelines for Post Resuscitation Induced Hypothermia

6. The Studies The Studies- 1. Bernard SA, Gray TW Treatment of comatose survivors of out-of- hospital cardiac arrest with induced hypothermia NEJM 2002;346:557- 563, Australia Results: 49% vs 26%, hypo vs normo, had a “good outcome”- as defined by discharge to home or rehab 2. Hypothermia After Cardiac Arrest Study Group. Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest NEJM 2002;346:549-556 Austria Results: 55% vs 39%, hypo vs normo, had a CPC-cerebral performance category score of “good recovery” or “moderate disability”

7. Epidemiology of Cardiac Arrest Approximately 450,000 people experience Sudden Cardiac Arrest (SCD) every year 95% of patients that have experienced SCD died before they reach the hospital

8. Pathophysiology Brain loses oxygen stores within 20 seconds Damage starts 4-6 minutes after the heart stops Glucose and adenosine triphosphate stores deplete (brain energy) Membrane depolarization Calcium influxes Glutamine is released Acidosis and edema develop Ischemia may persist for several hours after resuscitation (re-perfusion injury)

9. Cooling Cooling inhibits the process of cell destruction (apoptosis) caused by traditional resuscitation during reperfusion. When a patient is resuscitated, reperfusion sets off a series of chemical reactions that continue for up to 24 hrs, possibly causing significant inflammation in the brain.

10. Why make them Cool? ↓ Free Radical production ↓ ICP ↓ Cerebral metabolic rate ↓ Brains demand for 02 consumption Prevents mitochondrial damage and apoptosis Better chance of recovery with neurological function intact.

13. Cardiovascular Bradycardia Slight increase in blood Pressure (10mmHG) Mild arrhythmias Increased PR interval Increased QT interval Widened QRS Increased Systemic Vascular Resistance Increased Central Venous Pressure Decreased Cardiac Output

14. Hematologic Thrombocytopenia Impaired platelet function Leukopenia Impaired Leukocyte function Increased PT/PTT

15. Gastrointestinal Impaired Bowel Function Decreased GI motility/ Ileus Mild Pancreatitis (increased amylase) Increased liver enzymes

16. Pharmacokinetics Altered clearance of medications Clearance is slowed having a prolonged effect Keep this in mind when re-warming.

17. General Body attempts to maintain homeostasis Shivering Peripheral vasoconstriction Decreased circulation to skin

18. Metabolism Increased fat metabolism with increased production of glycerol, free fatty acids, ketonic acids, lactate Metabolic acidosis Decreased oxygen consumption Decrease CO2 production

19. Neurologic Decreased metabolic rate 5-7 % for each 1 degree C Decreased Cerebral Blood Flow (vasoconstriction) Decreased Magnesium- associated with worse outcomes. May Cause Cerebral and Coronary Vasoconstriction

20. Endocrine Increased epinephrine, Nor epinephrine, and Cortisol levels Hyperglycemia due to decreased insulin sensitivity and decreased insulin levels

21. Renal Diuresis Renal Tubular Dysfunction Electrolyte loss (K, MG, Ca, Phos)

22. Mechanics of Cooling Passive Cooling Ineffective have to wait on temperature to decrease to 33 ◦ Celsius Active Cooling Convection Air Cooling Blanket Therma cool Bair Hugger Conduction Ice packs Cold Blankets Infusion Cold NS infusion (2L over 4 hours)

24. Exclusion Criteria Pregnancy Age less than 18 years of age Known terminal illness/ Do Not Resuscitate Head Trauma Comatose state prior to cardiac arrest Coma for reasons other than cardiac arrest, such as drug overdose or seizure Active bleeding Core temp less than 86° F on admission Active infection requiring antibiotics at time of admission (systemic infection/sepsis)

25. Inclusion Criteria Cardiac arrest defined as absence of pulse requiring chest compressions regardless of location or presenting rhythm with return of spontaneous circulation (ROSC). Coma (does not follow verbal commands, no eye opening, no purposeful response to noxious stimuli) - Prior to sedation. Brainstem reflexes and pathologic posturing are permissible. Time down less than 60 minutes. Systolic Blood Pressure (SBP) > 90 mmHg and Mean Arterial Pressure (MAP) > 60 with or without the use of vasoactive medications. Intubated and ventilated via bag valve mask or mechanical ventilator. Initial temperature greater than 86° F. Confirmation of ICU Bed assignment.

26. Monitoring Vital Signs Q 15 min X 1 hour, then hourly. Core Temperature Q15 min until target reached then hourly. Continuous ECG monitoring. BIS Monitoring Glasgow Coma Scale hourly. FSBS hourly. I & O hourly. Assess skin Q2 hour. Obtain patient weight.

28. Complications of Hypothermia Pneumonia Risk Ventilator Dependency Decreased WBC / BM Suppression Decreased Inflammatory cytokines Elevated Glucose

29. Miscellaneous Complications Does NOT significantly increase metabolic acidosis or Lactate levels Will often cause mild HYPOTENSION, use Pressors to maintain MAP > 80 for cerebral perfusion (90 – 100) Drug Metabolism slowed significantly (Propofol / Fentanyl / Verapamil / Propanolol)

30. Shivering Increases O2 Consumption between 40 – 100% Shivering responses occur primarily between 30 – 35 C Sedation and anesthesia to halt shivering also increase Peripheral Blood Flow If you paralyze, you can’t screen for seizures Buspirone (Buspar) 30mg PO q 8hrs / hold for SCr > 1.7 Fentanyl 75mcg IV Use Paralytics as second line

31. The Future is in Our Hands

32. Reality is many patients with functional organs but non-functional Brain