Soto N, Towle Millard HA, Lee RA et al.
Purdue University, West Lafayette, IN, USA.
J Small Anim Pract 2014;55:415–9.
Kelly Bowlt’s review: The authors of this study aimed to determine whether or not pre-warming of intravenous fluids produces superior output temperatures compared with room temperature fluids at common anaesthetic fluid rates for small animal patients. This is important for the practitioner because a significant amount of nursing time can be taken up by warming fluids in a water bath or a costly fluid-warmer. In addition, warmed fluids can be utilised in anaesthetic-induced hypothermic animals in order to increase body temperature. Therefore, it is important to determine whether or not this is time and money well spent, or whether alternative methods of warming patients should be preferentially pursued. Anaesthetic-induced hypothermia results in numerous complications, including coagulopathies, myocardial ischaemia, resistance to or prolonged duration of drug action, and decreased resistance to infection.
This was a prospective, randomised, in vitro fluid-line, test-vein study. Nine flow rates were analysed (10mL/h, 20mL/h, 60mL/h, 100mL/h, 140mL/h, 180mL/h, 220mL/h, 260mL/h, and 300mL/h) for room temperature fluids (21°C) and for five pre-warmed fluids (40°C, 45°C, 50°C, 55°C, and 60°C). For each flow rate tested, room temperature fluids and pre-warmed fluids never exceeded 25.0°C and 25.5°C, respectively, at any time-point. The mean output temperatures of the pre-warmed fluids (at all of the pre-warming temperatures studied) were only significantly warmer than the room temperature fluids at a flow rate of 300mL/h.