Oesophageal PPG study
Research type
Research Study
Full title
Evaluation of photoplethysmographic (PPG) signals obtained simultaneously at two depths from the oesophagus
IRAS ID
139061
Contact name
Panayiotis Kyriacou
Contact email
Sponsor organisation
City University London
Research summary
When oxygen and blood delivery around the body is compromised – e.g. stress response or states of shock – blood is diverted away from the splanchnic area (gut and other abdominal organs) to more important organs such as the brain and heart, out of necessity to preserve life. It is vital to monitor the splanchnic region in critically ill patients as this situation can lead to the development of multiple organ failure and eventually death.
The proposed study aims to investigate reflectance photoplethysmographic (PPG) signals acquired from the mid and lower gullet (oesophagus) simultaneously. It is hypothesized that the lower oesophagus, which is supplied by branches of the celiac trunk, may have the capability of reflecting splanchnic perfusion. A miniaturised non-invasive optical probe comprising of two PPG sensors was developed to enable simultaneous monitoring and comparison of signals at two oesophageal levels.
In vivo studies will be firstly conducted on 20 patients undergoing general non-cardiac surgery, who require general anaesthesia and tracheal intubation as part of their procedure, in order to obtain a better understanding of the variations in blood supply of the entire length of the oesophagus. We will also conduct a larger study of 50 patients undergoing cardiac surgery (coronary artery bypass graft), where in such patients there might be a possibility of compromised perfusion which we hope will detect with the dual PPG probe.
Our research centre has shown the oesophagus to be a reliable and accurate monitoring site for PPG and pulse oximetry, and this study will provide a comparison to the different techniques that have been used in previous studies documenting variations of perfusion of the splanchnic circulation in cardiac surgery patients.
REC name
London - City & East Research Ethics Committee
REC reference
14/LO/0272
Date of REC Opinion
21 Mar 2014
REC opinion
Favourable Opinion