What is the protocol for targeted temperature management in cardiac arrest?

Targeted Temperature Management Protocol for Cardiac Arrest

All comatose adult patients with return of spontaneous circulation (ROSC) after cardiac arrest should receive targeted temperature management (TTM) with a target temperature between 32°C and 36°C maintained for at least 24 hours. 1

Patient Selection and Temperature Targets

• Strong recommendation for TTM in:

  • Ventricular fibrillation/pulseless ventricular tachycardia (VF/pVT) out-of-hospital cardiac arrest (OHCA) 1
  • Non-shockable rhythms (asystole or pulseless electrical activity) 2, 1
  • In-hospital cardiac arrest (IHCA) 2, 1

• Temperature selection considerations:

  • 36°C: Preferred for patients with bleeding risk or coagulopathy 1
  • 32-34°C: Preferred for patients with seizures or cerebral edema 1
  • No significant difference in survival or neurological outcomes has been demonstrated between TTM at 33°C versus 36°C in high-quality trials 1

Implementation Protocol

Phase 1: Induction

• DO NOT use pre-hospital cooling with rapid infusion of large volumes of cold IV fluid
  • Increases risk of re-arrest and pulmonary edema (Class III: No Benefit) 2, 1
• Begin cooling in-hospital using temperature control devices with feedback systems 1
• Options include:
  • Water or air circulating blankets/pads
  • Intravascular heat exchangers
  • Surface cooling devices

Phase 2: Maintenance

• Maintain target temperature for at least 24 hours 2, 1
• Continue even if target temperature is not fully achieved 1
• Use continuous temperature monitoring with feedback systems 1
• Monitor for and manage complications:
  • Bradycardia
  • Electrolyte disturbances
  • Increased vasopressor requirements
  • Seizures (occur in 12-22% of post-cardiac arrest comatose patients) 1
  • Hypothermia conditions may delay antiplatelet agent action (clopidogrel, ticagrelor, prasugrel) 2

Phase 3: Rewarming

• Controlled rewarming at 0.25-0.5°C per hour 1
• Avoid rapid rewarming as it may worsen neurological outcomes 1

Phase 4: Post-TTM Management

• Actively prevent fever (temperature >37.5°C) for 36-72 hours in patients who remain comatose 1
• Rebound hyperthermia is associated with increased mortality and worse neurological outcomes 1

Special Considerations

• Coronary angiography: TTM should not delay primary PCI in STEMI patients 2
• Prognostication: Earliest time for neurological prognostication is 72 hours after normothermia 1
• Ventilation management: Avoid hypoxia and hyperoxia, maintain PaCO₂ within normal physiological range 1

Common Pitfalls and Caveats

1. Pre-hospital cooling with cold IV fluids: Despite theoretical benefits of early cooling, pre-hospital infusion of cold fluids is not recommended and may be harmful 2, 1

2. Inadequate temperature monitoring: Continuous temperature monitoring with feedback systems is essential for effective TTM 1

3. Rapid rewarming: Can cause cerebral edema and worsen neurological outcomes; maintain controlled rewarming at 0.25-0.5°C per hour 1

4. Failure to prevent post-TTM fever: Active fever prevention should continue for 36-72 hours after TTM 1

5. Early prognostication: Clinical examination for prognostication should not be performed before 72 hours after normothermia 1

6. Antiplatelet medication effects: Be aware that hypothermia conditions may delay the action of antiplatelet agents 2