Transcript No Pressure” A Physiological Approach to the Management of

Time and Temperature is Brain:
Mild Therapeutic Hypothermia
for Post Cardiac Arrest Syndrome
Scott M. Silvers, MD
Mayo Clinic Jacksonville
Department of Emergency Medicine
2008 American Academy of Emergency Medicine
Scientific Assembly FERNE Symposium
February 8, 2008
Case
• November 11, 2007 at 0155 hours
• Patient is a 26yo male found unresponsive in a
pool of vomit by a friend in a corner of a garage
where he was spending the night.
• Unknown downtime
• EMS was called and found patient 's pupils fixed
and dilated upon arrival, and there has been no
spontaneous movement.
• He was treated with multiple drugs including
Narcan, glucose (secondary to a low glucometer
reading), epi, atropine, lidocaine, and bicarb.
• He was reportedly shocked x 2 for VFib and
arrived bradycardic and hypotensive with a
faintly palpable femoral pulse.
Case
• ET tube placement confirmed by auscultation and
ETCO2. Patient's pupils fixed and dilated, no
spontaneous movement. No corneal reflex.
• Temperature 33 °C. Accu-Check, 200+.
• The patient received 1 hour of continuous CPR
with defibrillation for VF and multiple doses of
ACLS drugs (see CPOE record and nursing notes)
• VF ocurred intermittently with asystole
• Ultrasound of his heart during this time revealed
no spontaneous movement.
• Finally, after a bolus of vasopressin and forceful
CPR, the patient developed a bradycardic rhythm
and weak pulse.
• Critical-care transported patient to the unit..
Case
Case
Question
• Can we offer anything more to improve
the outcome beyond hemodynamic
stabilization?
Arctic Sun Cooling System
Application of Pads
Continuous temperature
feedback with bladder
thermister
Hospital Discharge
• 12/19/07 (5 week stay)
• 26-year-old male who was found
unresponsive at a friend's house after
consuming cocaine and benzodiazepines.
• He was dependent on mechanical ventilation
for a week as well as vasopressors and
dialysis
• A tracheostomy was performed.
• After 2 days, we were able to discontinue the
oxygen support, and the patient was able to
breathe with good saturations through the
tracheostomy.
Hospital Discharge
• He was weaned off vasopressors.
• Nephrology concluded that he would be able
to be discharged without requiring further
dialysis.
• The patient was discharged afebrile,
hemodynamically stable, with no electrolyte
imbalances, with a normal urinary pattern and
without any respiratory issues.
American Heart Association
Background
• “Post Resuscitation” vs “Post Cardiac Arrest”
• 1953 First large multi-center report (N = 672)
– Adult inhospital cardiac arrest survival = 50%
• 2006 National Registry of CPR
– N = 19,819 adults; N = 524 children
– Adult inhospital cardiac arrest survival = 67%
– Children inhospital cardiac arrest survival = 55%
• 2007 AHA Statistics
– Adult OOH cardiac arrest survival = 6.3%
Ann Surg. 1953;137(5):731-744.
JAMA. 2006;295(1):50-57.
JAMA. 1966;198(4):372-379.
Post-Cardiac Arrest Injuries
• Brain Injury
• Myocardial dysfunction
• Systemic ischemia / reperfusion
response
• Unresolved pathologic process leading
to cardiac arrest
Post-Cardiac Arrest
Barriers to Care
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Pre-hospital and Hospital providers
Multiple hospital disciplines
Non-protocolized care
Limited ability for early prognostication
(< 72 hours post-arrest)
• Differing definitions among studies
Resuscitation. 2003;56(3):247-263.
Crit Care Med. 2006;34(7):1865-1873.
Resuscitation. 2007;74(2):227-234.
Resuscitation. 2006;70(3):404-409.
Resuscitation. 2007;73(1):29-39.
Survivor Outcomes
• Cerebral Performance Category (CPC)
– CPC 1: Good cerebral performance
– CPC 2: Moderate cerebral disability
• Outcomes of CPC 1 or 2
– Adults = 68%
– Children = 58%
JAMA. 2006;295(1):50-57.
Therapeutic Strategies
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General Measures
Monitoring
Hemodynamic Optimization
Oxygenation and Ventilation
Circulatory Support
Managing Underlying Pathology
Therapeutic Hypothermia
Sedation and Neuromuscular Blockade
Therapeutic Strategies
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Seizure Control and Prevention
Glucose Control
Neuroprotective Pharmacology
Adrenal Dysfunction Management
Renal Failure Management
Infection Management
AICD Placement
Long-Term Rehabilitation
Therapeutic Hypothermia
• 2 RCTs and a meta-analysis showed
improved outcome among adults remaining
comatose after OOH VF cardiac arrest
• Cooling to 32 - 34°C for 12 – 24 hours
• 4 studies with historical controls showed
benefit after non VF arrest
• Observational studies showed benefit with
other initial rhythms and in other settings.
Crit Care Med. 2005;33(2):414-418
Acta Anaesthesiol Scand. 2006;50(10):1277-1283.
Ann Emerg Med. 1997;30(2):146-153. Resuscitation. 2006;69(1):29-32.
Crit Care Med. 2006;34(7):1865-1873.
Meta-analysis
Alive at hospital discharge with favorable neurologic outcome:
Survival Risk Ratio = 1.68 (1.29 – 2.09); NNT = 6
Alive at 6 months with favorable neurologic recovery
Survival Risk Ratio = 1.44 (1.11 – 1.76); NNT = 6
Crit Care Med. 2005;33(2):414-418
Therapeutic Hypothermia
• Only therapy shown to increase survival
following cardiac arrest
• Ideal patients, technique, target temperature,
duration, and rewarming rate not yet
established
• Neuroprotection may decrease as the delay
in initiation of therapy increases
• Time to target temperature = 2 – 8 hours
Therapeutic Hypothermia
3 Phase Practical Approach
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Induction
Maintenance
Rewarming
If cooling not possible, prevent hyperthermia
– Risk highest 48 hours after resuscitation
– Poorer neurologic outcome each 1 °C > 37 °C
– Treatment: Antipyretics or active cooling
Therapeutic Hypothermia
Practical Approach
• Induction
– “Auto-cooling” or “after-drop” within 1st hour
– Ice chilled cold fluids (30 ml/kg NS or LR)
– Ice packs (head, neck, axilla, groin)
– Shivering prevention (sedation, NMB)
Therapeutic Hypothermia
Practical Approach
• Maintenance
– Continuous temperature feedback
– Surface or internal cooling
• Cooling blankets or pads
• Central Intravascular cooling catheters
• Cold wet blankets and ice
– Time consuming and less reliable
– Cold fluid infusions alone are not adequate
– 12 to 24 hours
Therapeutic Hypothermia
Practical Approach
• Rewarming
– Passive rewarming
– Active rewarming
• Internal or external cooling devices
• Other heating systems
– Goal 0.25 °C – 0.5 °C  per hour
– Careful monitoring
• Plasma electrolyte concentrations
• Hemodynamics
Key Points
• Our work is not completed after return of
spontaneous circulation
• Post-Cardiac Arrest Syndrome represents a
complex interaction of underlying pathologies
and the body’s response to hypoxia and
hypoperfusion
• Mild Therapeutic Hypothermia represents a
proven therapy that should be provided to
comatose, post-cardiac arrest patients
• Consider initiation of therapy in the ED for
patients remaining > 1 hour after ROSC
Thank you!
Questions?
[email protected]