Is targeted temperature management indicated for patients with Return Of Spontaneous Circulation (ROSC)?

From the Guidelines

Targeted temperature management (TTM) is indicated for comatose adult patients with return of spontaneous circulation (ROSC) after cardiac arrest, with a recommended target temperature between 32-36°C maintained for at least 24 hours 1.

Key Considerations

• TTM is particularly important for out-of-hospital cardiac arrests with an initial shockable rhythm.
• The implementation involves cooling the patient using external cooling devices or internal methods.
• Patients require sedation and possibly neuromuscular blockade during TTM.
• Core temperature should be continuously monitored via esophageal, bladder, or intravascular probes.

Benefits and Mechanism

• TTM works by reducing cerebral metabolism, decreasing free radical production, and limiting reperfusion injury, thereby protecting neurological function after the global ischemia that occurs during cardiac arrest.
• The optimal duration for mild induced hypothermia and TTM is unknown, although it is currently most commonly used for 24 h 1.

Patient Selection

• TTM is recommended for adults after out-of-hospital cardiac arrest (OHCA) with an initial shockable rhythm who remain unresponsive after ROSC 1.
• TTM is suggested for adults after OHCA with an initial nonshockable rhythm who remain unresponsive after ROSC.
• TTM is not universally recommended for all ROSC patients, particularly those with severe hemodynamic instability, active bleeding, or pre-existing severe neurological disability.

Monitoring and Rewarming

• After the maintenance period, rewarming should occur slowly at 0.25-0.5°C per hour to avoid complications.
• Patients should be monitored for potential complications, such as bradycardia, elevated lactate, and increased vasopressor support, during TTM 1.

From the Research

Targeted Temperature Management for ROSC Patients

• The use of targeted temperature management (TTM) in patients with return of spontaneous circulation (ROSC) after cardiac arrest is a topic of ongoing debate 2, 3, 4, 5, 6.
• Current guidelines recommend selecting and maintaining a constant target temperature between 32 and 36 °C for patients in whom TTM is used, as soon as possible after ROSC is achieved and airway, breathing, and circulation are stabilized 3.
• TTM at 32-34 °C does not appear to demonstrate improved outcomes compared with targeted normothermia, but fever should be avoided 2, 4, 5.
• The decision to opt for targeted hypothermia versus targeted normothermia should be made on a case-by-case basis, considering the individual patient's condition and the underlying cause of the cardiac arrest 3, 5.

Indications for Targeted Temperature Management

• Any survivor of cardiac arrest who is comatose should be considered as a candidate for TTM, regardless of the initial presenting rhythm 3, 6.
• TTM is advocated for adult patients who remain unresponsive following ROSC after either out-of-hospital cardiac arrest or in-hospital cardiac arrest 6.
• The benefit of TTM in patients with initial nonshockable rhythms is not clear, but some observational studies have suggested benefit 4, 5.

Temperature Control and Management

• The body temperature should be maintained at a constant value between 32 °C and 36 °C for at least 24 hours 6.
• To avoid rebound hyperthermia, fever following targeted temperature management should be prevented and treated for at least 72 hours after ROSC in persistently comatose patients 6.
• There is no evidence that any particular method of temperature regulation is superior 4.