Reducing Harm In Ventilated Patients: First In-patient Evaluation Of A Smart Endotracheal Tube
Lead Research Organisation:
University of Nottingham
Department Name: Faculty of Engineering
Abstract
In health, people can keep their airway open and breathe naturally. Seriously ill or anaesthetised patients however cannot do this, so clinicians often use an endotracheal tube (ETT) in the trachea (windpipe) to maintain an open airway and allow air to be delivered to the lungs via a mechanical ventilator. The tube is placed into the airway and a cuff (balloon) is inflated at the trachea to create a gas seal that allows air to be delivered to the lungs effectively.
To minimise injury and illness, it is important that this pressure is balanced correctly to avoid leaks and to protect the lungs from contamination. Unfortunately, due to the need for routine pressure measurements, tracheal injuries and ventilator associated pneumonia are common.
If the cuff pressure is too high this can cause injuries that range from moderate to severe sore throat in half of all patients after surgery (500,000 per year in the UK), to lifelong tracheal narrowing (Post Intubation Tracheal Stenosis, PITS) which occurs in around 2,000 patients per year in England. If the cuff pressure is too low this results in fluids leaking into the lungs which can lead to ventilator associated pneumonia (VAP). VAP affects as many as one in five people in intensive care, increases hospital stay by 6 days, costs the NHS £12,000 per episode and increases the likelihood of death. We aim to benefit intubated patients worldwide by creating a new medical device based on this world first technology.
iTraXS (intra tracheal multiplexed sensing) is a new endotracheal tube which uses fine optical fibre sensors in the cuff. The sensors use light to measure the pressure and blood flow at the interface between the cuff and trachea. Maintaining the correct cuff pressure can help to reduce tracheal injury and ventilator associated pneumonia. The sensors measure vital signs such as heart rate and oxygen saturation. The sensors can also identify when the ETT is incorrectly placed in the oesophagus, a potentially fatal situation. We think iTraXS is capable of improving the everyday experience of surgery for patients worldwide and will significantly reduce the suffering caused by VAP or PITS Within this project we will conduct the first clinical evaluation of this new technology with 40 adult participants undergoing elective surgery.
To minimise injury and illness, it is important that this pressure is balanced correctly to avoid leaks and to protect the lungs from contamination. Unfortunately, due to the need for routine pressure measurements, tracheal injuries and ventilator associated pneumonia are common.
If the cuff pressure is too high this can cause injuries that range from moderate to severe sore throat in half of all patients after surgery (500,000 per year in the UK), to lifelong tracheal narrowing (Post Intubation Tracheal Stenosis, PITS) which occurs in around 2,000 patients per year in England. If the cuff pressure is too low this results in fluids leaking into the lungs which can lead to ventilator associated pneumonia (VAP). VAP affects as many as one in five people in intensive care, increases hospital stay by 6 days, costs the NHS £12,000 per episode and increases the likelihood of death. We aim to benefit intubated patients worldwide by creating a new medical device based on this world first technology.
iTraXS (intra tracheal multiplexed sensing) is a new endotracheal tube which uses fine optical fibre sensors in the cuff. The sensors use light to measure the pressure and blood flow at the interface between the cuff and trachea. Maintaining the correct cuff pressure can help to reduce tracheal injury and ventilator associated pneumonia. The sensors measure vital signs such as heart rate and oxygen saturation. The sensors can also identify when the ETT is incorrectly placed in the oesophagus, a potentially fatal situation. We think iTraXS is capable of improving the everyday experience of surgery for patients worldwide and will significantly reduce the suffering caused by VAP or PITS Within this project we will conduct the first clinical evaluation of this new technology with 40 adult participants undergoing elective surgery.
Technical Summary
We have developed the world's first optical fibre sensor-equipped endotracheal tube (ETT), iTraXS (intra Tracheal multipleXed Sensing), an intelligent solution to provide personalised patient care during tracheal intubation and mechanical ventilation. It addresses the following unmet clinical needs:
(i) High cuff pressures cause tracheal injury: 3% of critically ill patients intubated >48hrs, suffer tracheal stenosis due to the cuff impairing mucosal perfusion (1900 resections per annum (pa), UK).
(ii) Tracheal inflammation (by the same mechanism) results in moderate/severe sore throat and voice changes in ~50% of intubated patients (0.5M pa, UK).
(iii) Low cuff pressure increases pulmonary aspiration of fluids, a major contributor to ventilator associated pneumonia (~15-25% of all critically ill patients, 5M pa, US, 235k pa, UK) with associated antibiotic treatment.
(iv) Unrecognised oesophageal intubation (~3% outside hospital) can result in cardiac arrest, severe brain damage or death due to hypoxia by asphyxiation.
iTraXS is a two-part device: a disposable sensor-equipped ETT, and a monitoring unit displaying cuff-trachea interface pressure, perfusion and oxygen saturation (SpO2). There is no ETT available that provides this monitoring capability to enable personalised care. For example, a 40kg, 1.5m tall, elderly person differs in internal tracheal geometry, vulnerability of tissue and disease pathology to a 120kg, 2m tall, otherwise fit 20 year-old. At present, this is bluntly addressed by a change in ETT size. Building on our healthy volunteer and animal studies, we are ready to take this potentially life-saving, innovative technology to 1st clinical evaluation (40 patients) to:
(i) Compare iTraXS SpO2 with blood gas analysis
(ii) Conduct measurements to inform ETT placement
(iii) Confirm the relationship between intracuff pressure, interface pressure and perfusion
(iv) Assess usability and inform future trials
(i) High cuff pressures cause tracheal injury: 3% of critically ill patients intubated >48hrs, suffer tracheal stenosis due to the cuff impairing mucosal perfusion (1900 resections per annum (pa), UK).
(ii) Tracheal inflammation (by the same mechanism) results in moderate/severe sore throat and voice changes in ~50% of intubated patients (0.5M pa, UK).
(iii) Low cuff pressure increases pulmonary aspiration of fluids, a major contributor to ventilator associated pneumonia (~15-25% of all critically ill patients, 5M pa, US, 235k pa, UK) with associated antibiotic treatment.
(iv) Unrecognised oesophageal intubation (~3% outside hospital) can result in cardiac arrest, severe brain damage or death due to hypoxia by asphyxiation.
iTraXS is a two-part device: a disposable sensor-equipped ETT, and a monitoring unit displaying cuff-trachea interface pressure, perfusion and oxygen saturation (SpO2). There is no ETT available that provides this monitoring capability to enable personalised care. For example, a 40kg, 1.5m tall, elderly person differs in internal tracheal geometry, vulnerability of tissue and disease pathology to a 120kg, 2m tall, otherwise fit 20 year-old. At present, this is bluntly addressed by a change in ETT size. Building on our healthy volunteer and animal studies, we are ready to take this potentially life-saving, innovative technology to 1st clinical evaluation (40 patients) to:
(i) Compare iTraXS SpO2 with blood gas analysis
(ii) Conduct measurements to inform ETT placement
(iii) Confirm the relationship between intracuff pressure, interface pressure and perfusion
(iv) Assess usability and inform future trials
