New rapid test for sepsis may help save thousands of lives

Researchers have developed an innovative, low cost test for earlier diagnosis of sepsis which could help save thousands of lives.

The simple system for sensitive real-time measurement of the life threatening condition is much quicker than existing hospital tests, which can take up to 72 hours to process, said researchers from the University of Strathclyde in the UK.

Using a microelectrode, a biosensor device is used to detect if one of the protein biomarkers of sepsis -- interleukin-6 -- is present in the bloodstream, they said.

IL-6 is a molecule secreted by the immune system and the levels of it in the blood increase in many of those who have the condition.

The results of the research project show that increased levels of the molecule can be detected by the test as quickly as two and a half minutes, researchers said.

The small size of the devices -- microelectrodes on a needle shaped substrates -- makes them ideal for initial testing and also continuous monitoring for sepsis, which is notoriously difficult to diagnose.

"The research shows that the tools we have developed could underpin a rapid test for sepsis," said Damion Corrigan from the University of Strathclyde.

"We have developed a needle shaped sensor with different electrodes and have shown we can detect one sepsis biomarker in almost real time, at the clinically relevant levels," Corrigan said.

"When levels go up, as they do in sepsis, we can detect that too. Sepsis is quite complex and difficult to diagnose but IL-6 is one of the best markers," said Corrigan.

"Our research so far shows you can measure a single sepsis marker, but there are actually eight sensors on the needle, each about the same diameter as a human hair and the idea is that in the future we can get multiple markers on the one microchip for a more comprehensive test," he said.

The device takes a pin prick of blood which is then put on the chip for the result to be read. Its needle shape means it can also be implanted and used on patients in intensive care.

The UK Sepsis Trust estimates that around 52,000 people in the UK die every year and six million globally from the condition, yet with early diagnosis and the correct treatment, most people make a full recovery.

Sepsis develops when the chemicals the immune system releases into the bloodstream to fight an infection instead cause inflammation throughout the entire body.

Without quick treatment, it can lead to multiple organ failure and death. A delay of just one hour for giving the correct antibiotic can mean an increase in the likelihood of death.

It is usually diagnosed based on simple measurements such as body temperature, heart rate and breathing rate, with patients often giving a blood test.

There is a reliance on clinical judgement and hospital laboratory techniques to diagnose the condition can take up to 72 hours to provide a result.

Researchers at the University of Leeds made the sensing element using microfabrication, while the Strathclyde team did all the measurements and developed the test using the sensor.

At the moment the 72 hour blood test is a very labour intensive process because the doctor orders the test on a computer with samples going to a central laboratory for processing and return of the result," Corrigan added.

"The type of test we envisage could for example be at the bedside and involve doctors or nurses being able to monitor levels of sepsis biomarkers for themselves," he said.