CFD Modeling of Hydrodynamics of Drug Infusion in Human Vein and Effect on Thrombophlebitis.

Patients receiving an intravenous (IV) drug infusion are at risk of developing thrombophlebitis, which is characterized by redness and swelling of the blood vein. The connection between IV infusion and thrombophlebitis is not entirely clear. It is crucial to characterize the evolving hemodynamic environment around the infusion site when developing new intravenous formulations, since too rapid dilution may cause precipitation in the vein, while too little dilution might cause phlebitis. In this study, a Large-Eddy Simulation (LES) turbulence modeling inside a Computational Fluid Dynamics (CFD) framework has been utilized to simulate the flow and mixing characteristics of an infusion entering the bloodstream. This work represents the first such study reporting transient flow fields for intravenous infusions using LES CFD simulations with a realistic non-Newtonian blood model. The output of the CFD model closely resembled the flow and mixing patterns generated in benchtop tests for infusions into a blood analogue and water as the venous fluid across a wide range of flow rates. These models were then investigated further to compare how changes to the fluid rheology model, needle orientation and needle position within the vein resulted in altered mixing regimes at different flow rates.