What are the recent guidelines for target temperature management in patients?

Recent Guidelines for Target Temperature Management (TTM)

Current guidelines recommend targeted temperature management (TTM) with a constant target temperature between 32°C and 36°C for at least 24 hours in comatose patients after return of spontaneous circulation (ROSC) following cardiac arrest. 1, 2

Patient Selection for TTM

TTM is recommended for different patient populations with varying levels of evidence:

• Strong recommendation: Out-of-hospital cardiac arrest (OHCA) with initial shockable rhythm 1, 2
• Weak recommendation: OHCA with initial non-shockable rhythm 1, 2
• Weak recommendation/Expert opinion: In-hospital cardiac arrest (IHCA) with any initial rhythm 1, 2

Temperature Selection

• Target temperature should be maintained constant between 32°C and 36°C 1
• No significant difference in survival or neurological outcomes has been demonstrated between TTM at 33°C versus 36°C 1
• Temperature selection considerations:
  • Higher temperatures (36°C) may be preferred for patients with bleeding risk or shock 1, 2
  • Lower temperatures (32-34°C) may be preferred for patients with seizures or cerebral edema 2
  • Initial patient temperature may influence selection - patients presenting at lower temperatures may be maintained at that level 2

TTM Implementation

1. Cooling methods:

   • Advanced servo-regulated cooling devices are strongly recommended for optimal TTM implementation 1
   • Surface or endovascular temperature control techniques with continuous temperature monitoring feedback systems are preferred 2

2. Duration:

   • Maintain target temperature for at least 24 hours 1, 2

3. Rewarming:

   • Perform controlled rewarming at a rate of 0.25-0.5°C per hour 2
   • Avoid rapid rewarming to prevent complications 2

4. Fever prevention:

   • Actively prevent fever (temperature >37.5°C) for at least 72 hours in patients who remain comatose 1, 2
   • It may be reasonable to actively prevent fever after TTM 1

Important Cautions and Contraindications

• Do not initiate TTM with infusion of large volumes of cold saline solution during transportation to the hospital 1

  • This has been associated with increased occurrence of re-arrest after ROSC and pulmonary edema 1

• Monitor for and manage potential complications:

  • Bradycardia (may actually be beneficial) 1, 2
  • Electrolyte disturbances 2
  • Increased vasopressor requirements (more common with lower temperatures) 1, 2
  • Seizures (occur in 12-22% of post-cardiac arrest comatose patients) 2

Special Considerations for Pediatric Patients

• In comatose children following resuscitation from OHCA or IHCA:
  • Recommend using TTM to maintain normothermia 1
  • Do not suggest using TTM between 32-34°C 1

Prognostication Timing

• The earliest time for prognostication using clinical examination in patients treated with TTM is 72 hours after normothermia 1
• For patients not treated with TTM, the earliest time to prognosticate poor neurological outcome is 72 hours after cardiac arrest 1

Quality Considerations

High-quality TTM implementation requires:

• Written standard operating procedures 3
• Feedback-controlled cooling devices 4, 5
• Adequate management of shivering (appropriate use of neuromuscular blocking agents) 4
• Consistent temperature monitoring and maintenance within target range 4, 5

Temperature deviations from target may be influenced by age, sex, body surface area, neuromuscular blocking agent doses, and type of cooling device used 4.