A method for estimating the delivery temperature of intravenous fluids

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Clinical Practice

Background:

• Current clinical practice lacks assessment of actual intravenous (i.v.) fluid delivery temperatures at the patient infusion site.
• Monitoring and controlling fluid temperature within a warmer does not guarantee the temperature at delivery.
• A quality assurance framework is needed to correlate warmer settings with delivery temperatures.

Purpose of the Study:

• To develop a method for assessing and controlling intravenous fluid delivery temperatures.
• To establish a correlation between warmer temperature and actual delivery temperature at the patient site.
• To provide a quality assurance framework for i.v. fluid temperature delivery.

Main Methods:

• Directly measured delivery temperatures for various i.v. fluids (saline, HES, albumin, plasma, PRC) using intratubing thermocouple probes.
• Utilized polyvinyl chloride (PVC) i.v. tubing of 0.260- and 0.300-cm diameters.
• Developed a kinetic analysis to establish a relationship governing temperature equilibration in i.v. tubing: f = L/(24 Q + L).

Main Results:

• The developed method accurately predicts i.v. fluid delivery temperatures.
• Fluid type and tubing construction variability had negligible effects on delivery temperature.
• The kinetic model enables calculation of temperature equilibration fraction (f) and delivery temperature based on tubing length (L) and flow rate (Q).

Conclusions:

• Effective assessment and control of i.v. fluid delivery temperatures are achievable despite complicating variables.
• The established relationship allows for calculation of delivery temperature or determination of tubing length/flow rate for a desired target temperature.
• This method enhances patient safety and optimizes therapeutic efficacy of i.v. fluid administration.