E-nose can 'sniff' out deadly bug

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An electronic nose has been developed which can identify potentially-fatal strains of pneumonia by "smelling" the breath of a patient.

The Breathatron, developed by doctors at Gloucestershire Royal Hospital, works by detecting chemicals in saliva.

It is being tested on intensive care patients on ventilators who are at risk of contracting pneumonia from the very equipment helping them to breathe.

Identifying the exact strain of the disease makes it easier to treat.

Metal oxide sensors

Patients given artificial breathing are most at risk of contracting Ventilator Acquired Pneumonia (VAP).

The consultant in charge of critical care at the Gloucestershire Royal Hospital, Chris Roberts, said: "The problem is the patient on a ventilator needs to be sedated and have a tube pushed down their nose and by being sedated they are often not able to cough and clear the secretions which can pool and track down into the lungs despite our best effort to stop this."

About one-in-four patients who are ventilated in intensive care units end up getting VAP and it can take days for laboratories to come back with results of what type of pneumonia they have.

Professor Hugh Barr, gastro-intestinal surgeon from the Gloucestershire Royal Hospital, has found a way of diagnosing VAP simply by smelling the vapour on a patient's breath.

The Breathatron has a metal oxide sensor that is affected in different ways by what are known at volatile organic compounds, which are given off by our lungs and gullet.

Preliminary results show the technology used by the machine can identify bacteria from pneumonia that can be treated with antibiotics.

For intensive care patients, it is simply a matter of diverting samples of their breath for instant analyses.

It's straightforward and easy to use. The science is complicated but the device is very straightforward Professor Hugh Barr

But Professor Barr says it will be some time before their final results are ready.

"We collect the data in a Breathatron and we also collected (samples) to store, to analyse the very specific smells," he said.

"And at the moment we are working out the details of what we have found.

"It's straightforward and easy to use. The science is complicated but the device is very straightforward.

"It is 80% to 90% accurate at the moment."

Pneumonia can often be very resistant to antibiotics, which is why it is essential to find the exact strain of the bug.

The machine, developed in conjunction with Cranfield University, was funded by the Cheltenham-based charity Gloucestershire Chest Fund and costs between £5,000 and 10,000.

A total of 100 ventilated patients have already used the machine as part of the clinical trial.

The Breathatron is also being developed for other trials in the detection of cancer and tubercolosis (TB).

The researchers said they believed it could eventually help to save more than a million people worldwide who die from TB every year.