Simulated clinical evaluation of four fluid warming devices*

Area of Science:

• Medical Devices
• Biomedical Engineering
• Anesthesiology

Background:

• Maintaining normothermia during medical procedures is crucial for patient safety.
• Various fluid warming devices are used to prevent hypothermia.
• Understanding the performance of these devices under different conditions is essential.

Purpose of the Study:

• To evaluate the fluid warming capabilities of four commonly used devices: Bair Hugger, Hotline, Standard Ranger, and Fluido.
• To compare device performance under gravity flow and pressurized conditions.

Main Methods:

• Laboratory evaluation of fluid warming devices.
• Testing under gravity flow (1m fluid head) and pressurized flow (300 mmHg).
• Measurement of fluid flow rates (70-450 ml/min) and delivered fluid temperatures at 22°C room temperature.

Main Results:

• No device consistently warmed fluid to the target 37°C at tested flow rates and room temperature.
• Standard Ranger (gravity) and Fluido (gravity and pressurized) achieved the highest temperatures (35°C).
• Bair Hugger and Hotline (gravity and pressurized) and Standard Ranger (pressurized) achieved lower temperatures (24-31°C).

Conclusions:

• Under tested laboratory conditions, none of the evaluated fluid warmers achieved 37°C.
• Calculations suggest all devices could reach target temperatures at their respective manufacturer-specified flow rates.
• Device performance is flow-dependent, highlighting the importance of adhering to manufacturer guidelines for optimal warming.