Evaluation of four methods of warming intravenous fluids.

OBJECTIVE: The purpose of this in vitro study was to compare four methods of warming intravenous fluid (IVF) with a control of unwarmed IVF at flow rates of 200, 400, 600, 800, and 1000 ml/hr. DESIGN: A 5 x 5 factorial experimental design was used to evaluate the methods of warming IVF and the control at varied flow rates. METHODS: The methods of warming IVF in this study included the following: (1) the Level 1 System 250 fluid warmer with D-60HL tubing (Level 1 Technologies, Inc., Rockland, Mass.); (2) the Level 1 System 250 fluid warmer with D-50 tubing (Level 1 Technologies, Inc.); (3) the Hotline fluid warmer with L-70 tubing (Level 1 Technologies, Inc.); and (4) the Baxter DW 1000 D blood fluid warmer with blood cuff set tubing (Baxter Healthcare Corporation, Valencia, Calif.). The IVF temperatures were measured with thermocouples at three points: (1) in the intravenous solution bag, (2) in the tubing after the infusion pump, and (3) 2 cm proximal to the end of the tubing. Ambient temperature and the temperature at the three measurement points were recorded when the temperature at the point 2 cm proximal to the end of the tubing was stable for 3 minutes. RESULTS: With single-lumen tubing, fluids flowing at low rates (e.g., 200 ml/hr) were barely warm at the end of the tubing. In contrast, fluid warmed with triple-lumen technology was consistently kept warm throughout the tubing.