Thermogard™ Efficacy Trial

Hypothermia in the severely burned has been shown to disrupt coagulation, impair myocardial function, weaken the host immune response, delay wound healing and increase mortality.

Current methods available for preventing and reversing hypothermia include administering heated, humidified oxygen, infusing warmed intravenous fluids centrally, performing peritoneal dialysis with warmed fluid, undergoing extracorporeal blood warming with partial bypass, and markedly increasing the ambient room temperature. These methods are either limited in their effectiveness or are impractical and potentially dangerous. Furthermore, the practice of markedly increasing the ambient room temperature creates a hostile work environment for health care providers which may impact patient care.

The FDA has classified the Alsius Thermogard™ heat exchange catheter as a Class II devices under 21 C.F.R §§ 870.5900. It is used in various clinical applications for cooling patients but it has not been FDA-approved for use in warming burn patients. The Thermogard™ is an integrated electro-mechanical heater/cooler that consists of a temperature monitor, a temperature controller unit, a heat exchanger unit, and roller pump. It supplies temperature controlled sterile saline to the indwelling catheter that is placed percutaneously in the patient. The catheter can be placed in the femoral vein (larger catheter with three heat exchange balloons) or the subclavian or jugular vein (smaller catheter with two heat exchange balloons).

Sterile saline is warmed (to a maximum temperature of 38 °C) in the external device and then pumped through the balloons coaxially mounted on the catheter, enabling direct warming of the blood. The catheter contains a temperature probe enabling a 'closed loop' temperature control system; the temperature is set at the desired level (the range of the device is 28-38°C, which may vary according to the installed software), after which the device warms the patient to this level by increasing or decreasing the temperature of the circulating saline. The core temperature is then maintained at the desired level for as long as the attending physician deems necessary. The catheter also has two ports for central venous access, which can be used to administer medication and/or for blood sampling.

The purpose of this study is to determine if the Thermogard™ central venous catheter can significantly impact the heat stress environment of the operating room by allowing severely burned patients to undergo surgery for debridement and grafting at lower ambient operating room temperatures when compared to control subjects.