What are the indications for Continuous Therapeutic Temperature (CTT) management in adult patients?

Indications for Targeted Temperature Management (TTM)

All adults who remain comatose (not following commands) after return of spontaneous circulation (ROSC) from cardiac arrest should receive targeted temperature management, regardless of arrest location or initial cardiac rhythm. 1

Primary Indications

Comatose Patients After ROSC

• Comatose state is defined as lack of meaningful response to verbal commands or inability to follow commands 1
• This applies universally to all comatose post-arrest patients, making neurological status the key determining factor rather than arrest characteristics 1

Out-of-Hospital Cardiac Arrest (OHCA)

Shockable rhythms (VF/pVT):

• TTM is strongly recommended for comatose survivors with initial shockable rhythms (strong recommendation, low-quality evidence) 1
• This represents the most robust evidence base from landmark trials 1

Non-shockable rhythms (PEA/asystole):

• TTM is suggested for comatose survivors with initial non-shockable rhythms (weak recommendation, very low-quality evidence) 1
• While evidence is weaker, observational data supports benefit in this population 2

In-Hospital Cardiac Arrest (IHCA)

• TTM is suggested for comatose survivors with any initial rhythm (weak recommendation, very low-quality evidence) 1
• The same principles apply regardless of arrest location 1

Target Temperature Selection

Maintain a constant temperature between 32°C and 37.5°C:

• The 2024 AHA guidelines expanded the acceptable range to 32°C-37.5°C, reflecting recent trial data 1
• Previous guidelines recommended 32°C-36°C 1
• No specific temperature within this range has proven superior for different patient subgroups 1
• The choice between 33°C versus 36°C showed no difference in outcomes in high-quality trials 3, 4

Duration of Temperature Control

Minimum 24 hours after achieving target temperature:

• TTM should be maintained for at least 24 hours (weak recommendation, very low-quality evidence) 1, 5
• After the initial 24-hour period, strict fever prevention should continue until 72 hours after ROSC, maintaining temperature <37.5°C 5
• No proven benefit exists for extending beyond 24 hours 5

Critical Exclusions and Contraindications

Do NOT use rapid cold IV fluid infusion in the prehospital setting:

• Prehospital cooling with rapid infusion of large volumes of cold IV fluid is not recommended (strong recommendation, moderate-quality evidence) 1
• This applies specifically to the prehospital phase; controlled in-hospital cooling methods are appropriate 1

Common Pitfalls to Avoid

Spontaneous hypothermia management:

• Patients with spontaneous hypothermia after ROSC who remain unresponsive should NOT be actively or passively rewarmed faster than 0.5°C per hour 1
• Rapid rewarming can cause secondary brain injury 5

Fever prevention:

• After completing the initial TTM period, actively prevent fever in persistently comatose patients (weak recommendation, very low-quality evidence) 1
• Fever is associated with worse neurological outcomes 1

Prognostication timing:

• Do not use clinical criteria alone before 72 hours after ROSC to estimate prognosis in TTM-treated patients 1
• Residual sedation and paralysis can confound examination 1

Implementation Requirements

Hospitals should develop standardized protocols:

• Institutional protocols for post-arrest temperature control are recommended 1
• TTM should be delivered as part of comprehensive post-resuscitation care including hemodynamic optimization, ventilation management, and consideration for coronary angiography 1