Evaluation of advanced cooling therapy's esophageal cooling device for core temperature control.

Managing core temperature is critical to patient outcomes in a wide range of clinical scenarios. Previous devices designed to perform temperature management required a trade-off between invasiveness and temperature modulation efficiency. The Esophageal Cooling Device, made by Advanced Cooling Therapy (Chicago, IL), was developed to optimize warming and cooling efficiency through an easy and low risk procedure that leverages heat transfer through convection and conduction. Clinical data from cardiac arrest, fever, and critical burn patients indicate that the Esophageal Cooling Device performs very well both in terms of temperature modulation (cooling rates of approximately 1.3°C/hour, warming of up to 0.5°C/hour) and maintaining temperature stability (variation around goal temperature ± 0.3°C). Physicians have reported that device performance is comparable to the performance of intravascular temperature management techniques and superior to the performance of surface devices, while avoiding the downsides associated with both.

Temperature modulation with an esophageal heat transfer device - a pediatric swine model study.

BACKGROUND: An increasing number of conditions appear to benefit from control and modulation of temperature, but available techniques to control temperature often have limitations, particularly in smaller patients with high surface to mass ratios. We aimed to evaluate a new method of temperature modulation with an esophageal heat transfer device in a pediatric swine model, hypothesizing that clinically significant modulation in temperature (both increases and decreases of more than 1°C) would be possible. METHODS: Three female Yorkshire swine averaging 23 kg were anesthetized with inhalational isoflurane prior to placement of the esophageal device, which was powered by a commercially available heat exchanger. Swine temperature was measured rectally and cooling and warming were performed by selecting the appropriate external heat exchanger mode. Temperature was recorded over time in order to calculate rates of temperature change. Histopathology of esophageal tissue was performed after study completion. RESULTS: Average swine baseline temperature was 38.3°C. Swine #1 exhibited a cooling rate of 3.5°C/hr; however, passive cooling may have contributed to this rate. External warming blankets maintained thermal equilibrium in swine #2 and #3, demonstrating maximum temperature decrease of 1.7°C/hr. Warming rates averaged 0.29°C/hr. Histopathologic analysis of esophageal tissue showed no adverse effects. CONCLUSIONS: An esophageal heat transfer device successfully modulated the temperature in a pediatric swine model. This approach to temperature modulation may offer a useful new modality to control temperature in conditions warranting temperature management (such as maintenance of normothermia, induction of hypothermia, fever control, or malignant hyperthermia).

Induction, maintenance, and reversal of therapeutic hypothermia with an esophageal heat transfer device.

AIM OF THE STUDY: To evaluate a novel esophageal heat transfer device for use in inducing, maintaining, and reversing hypothermia. We hypothesized that this device could successfully induce, maintain (within a 1 °C range of goal temperature), and reverse, mild therapeutic hypothermia in a large animal model over a 30-h treatment protocol. METHODS: Five female Yorkshire swine, weighing a mean of 65 kg (range 61-70) kg each, were anesthetized with inhalational isoflurane via endotracheal intubation and instrumented. The esophageal device was connected to an external chiller and then placed into the esophagus and connected to wall suction. Reduction to goal temperature was achieved by setting the chiller to cooling mode, and a 24h cooling protocol was completed before rewarming and recovering the animals. Histopathologic analysis was scheduled for 3-14 days after protocol completion. RESULTS: Average baseline temperature for the 5 animals was 38.6 °C (range 38.1-39.2 °C). All swine were cooled successfully, with average rate of temperature decrease of 1.3 °C/h (range 1.1-1.9) °C/h. Standard deviation from goal temperature averaged 0.2 °C throughout the steady-state maintenance phase, and no treatment for shivering was necessary during the protocol. Histopathology of esophageal tissue showed no adverse effects from the device. CONCLUSION: A new esophageal heat transfer device successfully and safely induced, maintained, and reversed therapeutic hypothermia in large swine. Goal temperature was maintained within a narrow range, and thermogenic shivering did not occur. These findings suggest a useful new modality to induce therapeutic hypothermia.