The development of the world’s first iTraXS – an optical fibre sensor-equipped endotracheal tube – is moving forward at Nottingham University following an £801,874 funding boost from the Medical Research Council.
Endotracheal tubes (ETTs) are placed in the trachea in patients who need artificial breathing support. iTraXS aims to prevent pressure injury to the airway and to assist with monitoring vital signs.
An ETT has an inflatable, balloon-like cuff, which sits inside the trachea and forms a gas-tight seal to prevent leaks of oxygen-rich air and maintain effective ventilation. The seal also protects the lungs from contamination by vomit or blood which can lead to ventilator-associated pneumonia (VAP), a condition that occurs in 8-28 per cent of ventilated ICU patients and costs the NHS an average of £12,000 per episode.
If cuff pressure is too low, it can risk fluid getting past the cuff and causing VAP, but if pressure is too high it can cause pressure injury in the trachea. Pressure injuries range from moderate to severe sore throat, voice change or cough in half of all patients after surgery, to permanent scarring and narrowing of the windpipe tissue (post intubation tracheal stenosis, or PITS), which occurs in around 2000 patients annually. PITS is a disabling condition, with patients living ‘from breath to breath’ and reporting long-term adverse impact on quality of life.
According to Nottingham University, there is no medical device on the market to accurately and safely measure and monitor the contact pressure of the inflated cuff and the blood flow in the tracheal lining.
Current best practice recommends maintaining a fixed pressure in all patients whereas iTraXS will enable personalised care by allowing clinical staff to find the correct pressure for each patient, balancing a good seal against tissue pressure and blood flow.
iTraXS uses thin, flexible, optical fibre sensors incorporated into a standard disposable ETT, which is linked to an optoelectronic monitoring and display unit.
The device monitors the contact pressure and the blood supply at the cuff-trachea interface to ensure a good gas seal while avoiding windpipe injury. ITraXS measurements could also aid ETT placement and vital sign monitoring in pre-hospital conditions.
In a statement, Steve Morgan, Professor of Biomedical Engineering and co-director at the Centre for Healthcare Technologies, said, “iTraXS demonstrates the potential of emerging optical sensor technology to enable real-time monitoring inside patients, providing previously unavailable data to aid clinical decision making and improving the surgical experience of patients worldwide.”
With the MRC funding, the researchers aim to develop regulatory compliant software and hardware and expand the number and functionality of sensors built into iTraXS. At the end of the current project the device will be ready for clinical trials and could be CE-marked and brought to market within three years.
ITraXS has been developed in partnership with P3 Medical Ltd, a Bristol-based manufacturer of endotracheal tubes and Nottingham University Hospitals NHS Trust.