Comparing Therapeutic Hypothermia Using External and Internal Cooling for Post-Cardiac Arrest Patients

Controlled therapeutic hypothermia is a method of preserving neurological function post-resuscitation.It has been associated with improved functional recovery and reduced histological deficits in animal models of cardiac arrest.

Three randomized clinical studies have been reported showing improved neurological outcome and reduced mortality in post-resuscitation patients treated with hypothermia compared to controls. Of the various methods of inducing hypothermia, internal cooling using an endovascular catheter and external cooling using gel pads with a water based circulating system have shown the most promise. There have not been any studies looking at outcomes between the two methods of cooling.

• Device: Internal Device (Alsius Thermogard)
  The intravascular cooling system uses a single lumen (8.5 Fr,38 cm) central venous catheter inserted into the inferior vena cava via the left or right femoral vein. Normal saline is pumped through three balloons mounted on the catheter and returned to a central system in a closed loop. The saline flow within the balloons is in close contact with the patient's blood flow and serves as a heat exchange system. An automatic temperature control device adjusts the temperature of the circulating saline (4°C to 42°C) based on the patient's core temperature.
  Other Name: Alsius Thermogard
• Device: External Device (Arctic Sun)
  The gel-coated external cooling device consists of four water circulating gel coated energy transfer pads, and is placed on the patient's back, abdomen, and both thighs. Depending on the size used, the total surface area ranges between 0.60 and 0.77 m2. It is connected to an automatic thermostat controlling the temperature of the circulating water (4°C to 42°C) based on the patient's core temperature.
  Other Name: Arctic Sun

• Active Comparator: Surface Cooling
  Intervention: Device: External Device (Arctic Sun)
• Active Comparator: Internal Cooling
  Intervention: Device: Internal Device (Alsius Thermogard)

Inclusion Criteria:

1. Sustained return of spontaneous circulation (ROSC) after cardiac arrest, for more than 30 min
2. Patients aged between 18 to 80 years.
3. Patients who are hemodynamically stable, with a systolic BP > 90 mmHg with or without inotropic support.
4. Patients comatose or unresponsive post-resuscitation

Exclusion Criteria:

1. Hypotension despite fluid and/or vasopressor support
2. Positive pregnancy test in women below 50 years
3. Premorbid status bedbound and uncommunicative