What is the management of Ventricular Fibrillation (VFib) arrest with Return of Spontaneous Circulation (ROSC) using Therapeutic Hypothermia (TTM)?

From the Guidelines

Management of a ventricular fibrillation (VFib) cardiac arrest with return of spontaneous circulation (ROSC) should include targeted temperature management (TTM) by cooling the patient to a target temperature between 32°C and 36°C for at least 24 hours, as recommended by the 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care 1. This approach can be achieved using external cooling devices or internal methods, and it is essential to start cooling as soon as possible after ROSC. Some key points to consider in TTM management include:

• Administering sedation and analgesia to prevent shivering
• Monitoring core temperature continuously
• Maintaining MAP >65 mmHg using vasopressors if needed
• Rewarming slowly at 0.25-0.5°C per hour after 24 hours to avoid hypotension, electrolyte shifts, and increased intracranial pressure. The European Resuscitation Council and European Society of Intensive Care Medicine 2015 guidelines for post-resuscitation care also support the use of TTM, recommending a target temperature between 32°C and 36°C for adults after OHCA with an initial shockable rhythm who remain unresponsive after ROSC 1. Additionally, the guidelines suggest that TTM may be beneficial for adults after OHCA with an initial nonshockable rhythm who remain unresponsive after ROSC. It is crucial to note that the optimal duration for mild induced hypothermia and TTM is unknown, but 24 hours is currently the most commonly used duration. The use of TTM has been shown to reduce cerebral oxygen consumption, decrease free radical production, and reduce excitatory amino acid release, thereby protecting the brain from secondary injury following cardiac arrest. In the context of real-life clinical medicine, it is essential to prioritize the patient's morbidity, mortality, and quality of life when making decisions about TTM management, and to consider the latest evidence and guidelines when developing a treatment plan. For example, the 2015 guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care recommends against the routine prehospital cooling of patients after ROSC with rapid infusion of cold intravenous fluids 1. Overall, TTM is a critical component of post-cardiac arrest care, and its use should be guided by the latest evidence and guidelines to optimize patient outcomes.

From the Research

VFIB Arrest with ROSC TTM Management

• The management of patients with return of spontaneous circulation (ROSC) following cardiac arrest is a critically important population requiring close monitoring and targeted interventions in the emergency department (ED) 2.
• Targeted temperature management (TTM) is the only strategy shown to reduce the risk of neurologic disability in cardiac arrest patients 3.
• TTM at 32-34° C does not appear to demonstrate improved outcomes compared with targeted normothermia, but fever should be avoided 2.
• A target temperature of 33 °C was not superior to 36 °C, suggesting that a lenient targeted temperature may be appropriate especially for patients unable to tolerate lower temperatures 3.
• The body temperature should be maintained at a constant value between 32 °C and 36 °C for at least 24 h 4.
• To avoid rebound hyperthermia, fever following targeted temperature management, defined as a temperature above 37.7 °C, should be prevented and treated for at least 72 h after ROSC in persistently comatose patients 4.

Optimal Time for TTM

• Survival and good neurologic outcome are closely associated with the time of collapse to ROSC 5.
• The optimal time for TTM is between 20-40 min of collapse to ROSC 5.
• Applying TTM with <20 min or more than 40 min of collapse to ROSC did not improve survival or neurologic outcome 5.

TTM in Specific Patient Populations

• TTM is effective in patients with VFIB arrest and ROSC, and can improve neurological outcomes 6.
• TTM can be used in patients with cardiac arrest caused by thyroid storm, and can improve outcomes 6.
• The routine use of prehospital cooling by rapid infusion of large volumes of cold i.v. fluid immediately after ROSC is not recommended 4.