Preventive effect of fluid warmer system on hypothermia induced by rapid intravenous infusion

The changes in body temperature induced by rapid intravenous infusion of lactated Ringer solution and the effect of a fluid warmer system (HOT LINE(TM), Level 1 Technologies, Inc., Rockland, MD) were investigated in 35 patients undergoing cardiovascular surgery. The patients were divided into 5 groups by categories of the fluid temperature (~19 or ~38°C), infusion route (radial or right subclavian vein), and infusion rate of lactated Ringer solution (1000 or 250 ml for 30 min). Pulmonary arterial, esophageal, bladder, and forehead deep temperatures, which reflect core temperature, were significantly decreased by the rapid infusion of unwarmed solution (0.8- 1.0°C, P < 0.05). In contrast, these temperatures were maintained in the warmed solution groups as well as in the group of slow infusion rate. With regard to the infusion route, there was no significant difference in the temperature between the radial vein and subclavian vein groups. Plantar deep temperature showed no significant change during this study. In conclusion, infusion of warmed solution using HOT LINE(TM) could prevent hypothermia induced by rapid intravenous infusion, and this effect is not greatly influenced by route of venous infusion.