In 1989, transfusions of one or two units of blood at low flow rates (less than 25ml/min) accounted for more than 60% of the 3.2 million U.S. patients who received a total of 12.1 million units of red blood cells. A warming device that could deliver fluids, including blood, at normothermic temperature at low flow rates would prove useful for the prevention of hypothermia, particularly in neonatal and pediatric patients for whom low flow rate infusions and transfusions are the norm. The long-term objective of this proposal is to develop a warming device capable of delivering intravenous fluids and blood at normothermic temperatures at low flow rates consistent with neonatal and pediatric use. The innovative aspects of this device are that it will be small (less than 147cm3), lightweight (approximately 113g), and will have a small priming volume (less than 1.4ml). More important, this device will be designed to have no supply voltages in the heating cavity, thereby allowing the device to be located very close to the patient. This will substantially reduce patient-line cooling, yet allow more convenience of use compared with devices which are water-jacketed right up to the IV site.
A warmer that could safely deliver fluids at normothermic temperature at low flow rates would prove useful in the prevention of hypothermia, particularly in small patients. To accomplish this, the warming device should be located in close proximity to the patient. Commercial acceptance of such a device is assured.
