Welsh scientists hope to drastically reduce kidney and blood infections in UK hospitals after developing an early warning system for patients fitted with catheters.

Cardiff University academics say thousands fitted with the devices on a long-term basis are frequently at risk of serious complications because catheters can get blocked “without warning”.

They have now come up with a sensor that fits on to the tubes, which changes from yellow to blue/black before it becomes blocked, allowing doctors to treat infection before complications arise.

David Williams from Cardiff University’s School of Medicine, who led the development, said: “The implic-ation to a patient’s health if the catheter gets blocked is serious.

“Not only does it lead to extreme discomfort, but can cause other clinical problems which may prove fatal.

“There is currently no effective method to manage this problem. Catheter blockages remain uncontrollable, unpredictable and dealt with – more often than not – when it’s too late. This is extremely painful for the patient, frustrating for the doctors and a massive drain on finances.

“By developing the first early warning system for urinary catheter blockage we hope we can offer doctors and nursing staff an accurate way of predicting and preventing encrustation before it is too late.”