Delivery temperature of heated intravenous solutions during rapid infusion

Warming of intravenous fluids may help to prevent shivering and hypothermia in the surgical patient. Increasing the fluid temperatures to as high as 60 degrees C has been suggested. An in vitro study was performed in which temperature changes following the rapid infusion of heated lactated Ringer's solution within a vein were measured. When 1 L of solution was warmed to 55 degrees C and then was infused over 4 min, local model vein temperatures rose from 37 degrees C to 44 degrees C. This effect of possible regional tissue heating may well occur in vivo. It is known that the rate of human blood cell hemolysis and membrane enzymatic function is affected by temperature. Further efforts need to be directed toward appreciating the effects of warmed intravenous fluids upon intact physiologic preparations and red blood cells.