Biomedical engineers investigate why millions of catheters fail

Researchers from the Harry Perkins Institute of Medical Research have helped explain the high failure rate of one of the most commonly used medical devices in the world.  

More than one billion disposable intravenous (IV) catheters are used every year and up to 50% of them fail, leading to an increased risk of infection for patients.

Catheters are small, flexible tubes often inserted into a vein to deliver medicines and fluids into the blood stream.

Biomedical engineer and head of the Perkins Vascular Engineering Laboratory (VascLab), Dr Barry Doyle, said catheter failure can arise when the connection becomes loose in the vein or blocked.

The team studied a range of factors, including the angle of insertion, the position of the catheter tip, the size of the catheter and the speed at which fluids are injected into the blood stream.

With that information they developed a computational model of the fluid movement.

By simulating the movement and forces of fluid in the veins they found that in certain circumstances, such as when the catheter tip is near the far wall of the vein, pressure on the vein can be up to 3500 times above normal.

Such significant pressure can cause damage to the blood cells and the vessel wall itself.

That damage could be triggering a biological response, such as inflammation or thrombosis, which could contribute to the device blocking or becoming loose and ultimately failing.

The researchers plan to use their findings in clinical studies and develop a simple look-up chart to help medical professionals choose the catheter to suit the vein and determine the impact of fluid pressure.

The aim is to help nurses, clinicians and specialists become more aware of the forces at play and how they co-contribute to catheter use failure.

The findings were published in the high impact journal Scientific Reports and were a collaborative effort between the Alliance for Vascular Access Teaching and Research (AVATAR), Harry Perkins Institute of Medical Research, The University of Western Australia, Griffith University and Queensland University of Technology.