Therapeutic hypothermia after cardiac arrest podnos

Therapeutic Hypothermia after Cardiac Arrest

Steven Podnos MD

Sudden cardiac death (SCD) is an unexpected death due to cardiac causes occurring in a short time period in a person with known or unknown cardiac disease in whom no previously diagnosed fatal condition is apparent

Approximately half of all cardiac deaths can be classified as SCDs

Often the first expression of cardiac disease in many individuals presenting as out-of-hospital patients with cardiac arrest

SUDDEN CARDIAC DEATH

SCD accounts for approximately 325000 deaths per year in the United States

gt lung cancer breast cancer or AIDS ~ 40 unwitnessed For most survival depends on competent performance of basic life

support defibrillation and advanced life support and hospital transfer Roughly 20 of patients who have out-of-hospital cardiac arrest

survive to hospital discharge The most important determinants of survival include

(1) an unsupported systolic blood pressure gt 90 mm Hg(2) a time from loss of consciousness to return of spontaneous circulation (ROSC) of less than 25 minutes(3) some degree of neurological responsiveness

30-80 of cases result in anoxic encephalopathy

Incidence Morbidity and Mortality

HYPOTHERMIA-THEORY OF ACTION

Reduce Metabolic Rate and Oxygen Consumption in setting of Reduced Oxygen Supply

Suppress Reperfusion Injury

2005 AHA Guidelines

Providers should not actively rewarm hemodynamically stable patients who spontaneously develop a mild degree of hypothermia (33degC [915degF]) after resuscitation from cardiac arrest

Unconscious adult patients with ROSC after out-of-hospital cardiac arrest should be cooled to 896degF to 932degF for 12 to 24 hours when the initial rhythm was VF (Class IIa)

Similar therapy may be beneficial for patients with non-VF arrest out of hospital

Clinical Trial Outcomes

Among patients surviving out-of-hospital cardiac arrest use of induced hypothermia treatment leads to improved (almost twice as good) neurological outcomes at 6 months in three trials One of three trials suggested an improved overall survival

Side Effects of Hypothermia

1048698darrdarrHR 1048698darrdarrPhosphate and potassium concentration 1048698darrdarrGut motility 1048698uarruarrBlood Glucose 1048698uarruarrVascular resistance 1048698uarruarrsolubility of gases in blood 1048698Prolongs clotting times

Whorsquos a Candidate

Out-of of-Hospital cardiac arrest with return of spontaneous circulation (ROSC) Intubated and Ventilated Treatment within 6 hours after ROSC Systolic BP gege90 mmHg (with or without vasopressorvasopressor) Coma or GCS = 3

Cautions with Hypothermia

Intracranial hemorrhage Major Surgery within 14 days (uarruarrrisk of

infectionbleeding) Systemic infectionsepsis (inhibits immune function) Known bleeding disorders or active bleeding Temperature lt 30 degrees C after cardiac arrest

Cooling Techniques

Non-Invasive Techniques and 1048698 Cooling blanketspads 1048698 Ice packs 1048698 Caps or helmets 1048698 Immersion in cold water 1048698 Self-adhesive hydrogel cooling pads Invasive Techniques 1048698 Infusion of cold IV fluids 1048698 Heat exchange catheter 1048698 Extracorporeal circulating cooled blood 1048698 Retrograde jugular vein flush 1048698 Nasal nasogastric lung amp rectal lavage 1048698 Peritoneal lavage with cold exchanges 1048698 Intraventricular cerebral hypothermia

Cooling

Avoid initial rewarming Continue other therapies as indicated Begin treatment early-after excluding IC Bleed Usually initiation begins in the ED Trend towards EMS initiating cooling in fieldTrend field Treatment is then continued in the cath lab andor ICU

Cooling Phase

Continuously Monitor Temperature with Core temp probes (ie esophageal pulmonary artery bladder probe etc)

Connected to Cooling Unit Use a Cooling secondary temperature to monitor

patient temperature-Done every 30 minutes during cooling and rewarming

Done every hour during maintenance-Bladder probe is only accurate when there is adequate urine output

Prevent Shivering

Usually use Paralytics when Temp less than 36 degrees

Testing

Tests 1048698CBC with Diff 1048698Chem 1048698Glucose 1048698Troponin 1048698PTPTTINR 1048698Magnesium 1048698Phosphorus 1048698CPK 104869812 Lead EKG 1048698Portable Chest 1048698UA Dip 1048698AcchuCheckQ 2 hours 1048698ABG 1048698Labstests at 6 12 amp 18 hours can include 1048698Potassium 1048698Glucose 1048698Troponin 1048698ABG

Supportive Therapy

Keep MAP 80-100 Norepinephrine may be used beginning to titrate

MAPgt 80 mmHg Monitor for arrhythmia Most commonly bradycardia Discontinue hypothermia for Significant dysrhythmias Hemodynamic instability Active bleeding

Rewarming

The rewarming phase may be the most critical as the constricted peripheral beds start to dilate sometimes leading to hypotension

Literature recommends rewarming slowly at a temperature of 03-05deg C every hour

It will take about 8 hours to rewarm

Rewarming

Rewarming is initiated 24 hours after the initiation of cooling

Maintain sedation until temp of 35 degrees is reached

If neuromuscular blockade is in use to prevent shivering DC the blockade first and then discontinue sedation

Monitor for hypotension secondary to vasodilatation induced by rewarming

Discontinue potassium infusions Goal of rewarming is normothermia

SUMMARY

Evidence supports use of therapeutic hypothermia in the comatose survivors of out-of-hospital cardiac arrest

Should be initiated ASAP after Return of Spontaneous Circulation but appears successful even if delayed (eg 4--6 hours)

Sudden cardiac death (SCD) is an unexpected death due to cardiac causes occurring in a short time period in a person with known or unknown cardiac disease in whom no previously diagnosed fatal condition is apparent

Approximately half of all cardiac deaths can be classified as SCDs

Often the first expression of cardiac disease in many individuals presenting as out-of-hospital patients with cardiac arrest

SUDDEN CARDIAC DEATH











2005 AHA Guidelines













Cooling Techniques


Cooling


Cooling Phase





Prevent Shivering


Testing


Supportive Therapy



Rewarming




Rewarming






SUMMARY













2005 AHA Guidelines













Cooling Techniques


Cooling


Cooling Phase





Prevent Shivering


Testing


Supportive Therapy



Rewarming




Rewarming






SUMMARY












Cooling Techniques


Cooling


Cooling Phase





Prevent Shivering


Testing


Supportive Therapy



Rewarming




Rewarming






SUMMARY



Cooling


Cooling Phase





Prevent Shivering


Testing


Supportive Therapy



Rewarming




Rewarming






SUMMARY



Cooling Phase





Prevent Shivering


Testing


Supportive Therapy



Rewarming




Rewarming






SUMMARY



Prevent Shivering


Testing


Supportive Therapy



Rewarming




Rewarming






SUMMARY



Testing


Supportive Therapy



Rewarming




Rewarming






SUMMARY



Supportive Therapy



Rewarming




Rewarming






SUMMARY



Rewarming




Rewarming






SUMMARY



Rewarming






SUMMARY



SUMMARY



Therapeutic hypothermia after cardiac arrest podnos

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