23 February 2018
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 a variety of problems such as increased risk of infection for patients.
These catheters are small, flexible tubes that are inserted into a vein to deliver medicine and fluids into the blood stream.
Biomedical engineer and head of the Perkins Vascular Engineering laboratory, Dr Barry Doyle, said catheter failure arises when the small tube becomes blocked or the connection becomes loose in the vein.
“We studied a range of factors, such as the angle that the IV catheter is inserted, 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 we developed a computational model of the fluid movement,” Dr Doyle said.
“We simulated the movement and forces of fluid in the veins and found that certain configurations of catheter and vein, such as when the catheter tip is near the far wall of the vein, results in very large forces on the vein, especially when the fluid is infused quite fast. We found that it can exceed the normal forces by about 3500 times.”
“We believe that significant fluid forces 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 then be contributing to the device blocking or becoming loose and ultimately failing.”
This study was developed with vascular access clinician and researcher Dr Peter Carr from the School of Medicine at UWA, who specifically investigates peripheral intravenous catheter failure.
“With this knowledge we can attempt to modify our insertion practice in addition to how we care and maintain these devices. The potential impact, when translated to clinical practice could be very significant for both patients and hospitals,” Dr Carr said.
The researchers plan to use their findings to move forward with clinical studies, with the hope of developing a simple look-up chart to help medical professionals choose the catheter to suit the vein and determine the impact of fluid pressure.
“We want to help nurses, clinicians and specialists become more aware of the forces at play and how they co-contribute to catheter failure,” Dr Doyle said.
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) group, Harry Perkins Institute of Medical Research, The University of Western Australia, Griffith University and Queensland University of Technology.