Quality Assessment of the Efficiency of the Warming Cabinet Method in Warming Fluids in Anaesthesia

In this observational study, we assessed the efficiency of the use of a 40° C warming cabinet method for heating intravenous (IV) fluids administered to patients during surgery. 24 bags of Ringers lactate were placed in a warming cabinet set at 40° C. Fluid temperatures at two points of the delivery system (bag and patient end) were measured every 3 minutes for 15 minutes after being removed from the warming cabinet.

Results: The bag temperature (34-31 °C) was significantly lower than 40°C but remained above room temperature throughout the study period. The patient–end temperatures were significantly lower than bag temperatures for all time-periods (p<0.01) and were similar to room temperatures within 3 minutes. We conclude that the quality of the warming cabinet technique used in operating theatres to warm fluids prior to IV infusion, is clinically inefficient and fails to deliver the IV fluids at a warm enough temperature and may therefore put patients at risk of unanticipated hypothermia. We recommend that the practice of the studied method of fluid warming needs to be revised and replaced by another method which could be more clinically effective and reliable in keeping the patient’s temperature within normal limits under anaesthesia.

Keywords: Hypothermia; Prevention; Hypothermia; Physiology effects