Observational in-vitro study comparing the efficacy of fluid warming devices: Ranger© 24500 versus ANIMEC AM-2S

Abstract

Background: Intraoperative hypothermia is detrimental to the patient. This, however, can be minimized with infusion of warmed fluids. Objectives: We investigated the warming capabilities of the Ranger© 24500 (Ranger) and ANIMEC AM-2S (ANIMEC) at various low infusion rates. We also examined the use of two ANIMEC warmers placed in series along the intravenous tubing. Methods: We had three comparative trial groups for our experiment. Trial group 1 involved the use of an ANIMEC fluid warmer. Trial group 2 involved the use of two ANIMEC fluid warmers placed in series. Trial group 3 involved the use of the Ranger. Three different infusion rates (1 ml/min, 5 ml/min and 10 ml/min) were examined. Results: The use of two ANIMEC fluid warmers delivered the warmest fluid in all three study infusion rates. The mean (SD) delivered temperature was 24.11 (0.62)°C at 1 ml/min, 29.59 (0.10)°C at 5 ml/min and 29.27 (0.10)°C at 10 ml/min. The Ranger delivered the lowest temperatures at infusion rates of 1 ml/min and 5 ml/min. The mean temperatures were 21.01 (0.38)°C and 23.87 (0.34)°C respectively. The mean temperatures of utilizing one ANIMEC fluid warmer were 21.49 (0.35)°C, 25.47 (0.08)°C and 24.78 (0.12)°C at infusion rates of 1 ml/min, 5 ml/min and 10 ml/min respectively. Conclusion: The ANIMEC performs better than the Ranger at low flow rates of up to 5 ml/min. A novel method of placing the two ANIMEC warming devices in series can further improve its warming capabilities.