Hydrodynamic evaluation of intravenous infusion systems

Area of Science:

• Fluid dynamics
• Medical device engineering
• Clinical engineering

Background:

• Rapid fluid resuscitation is critical in emergency medicine.
• Understanding the hydrodynamic properties of intravenous (IV) infusion sets is essential for optimizing fluid delivery.
• Previous studies focused on overall flow rates, lacking component-specific hydrodynamic analysis.

Purpose of the Study:

• To quantitatively evaluate the hydrodynamic characteristics of IV infusion sets and their components.
• To determine flow resistance across various IV set parts under different infusion pressures.
• To identify key factors influencing flow rates for effective fluid resuscitation.

Main Methods:

• Developed a quantitative technique to measure flow resistance in IV sets and components.
• Tested standard IV sets with 14- and 18-gauge IV catheters.
• Evaluated performance across a range of infusion pressures from 50 mm Hg (gravity) to 400 mm Hg.

Main Results:

• Under gravity flow, the drip chamber resistance is comparable to the catheter's.
• With pressurized infusion and small catheters, the catheter dominates pressure drop.
• At high pressures with large catheters or tubing, the drip chamber becomes the primary flow resistance.

Conclusions:

• For gravity flow, low-resistance drip chambers or dual infusion sites are most effective for increasing flow.
• Under pressurized conditions (>200 mm Hg), larger gauge catheters (14 vs. 18) offer greater flow improvement than doubling infusion sites.
• Efficient drip chambers provide significant benefits; increased tubing diameter offers minimal advantage.