VCs in exhaled breath during intense exercise
Research type
Research Study
Full title
Ammonia and Volatile organic compounds in expired breath during intense exercise in healthy volunteers
IRAS ID
229877
Contact name
Angella Bryan
Contact email
Sponsor organisation
Manchester University NHS Trust
Duration of Study in the UK
0 years, 7 months, 31 days
Research summary
Research Summary
This study uses vigorous exercise on a bicycle ergometer to mimic the changes in metabolism that occur in severe illness.
There is a need for the development of new technologies to facilitate the clinical optimization of sick patients in the critical care unit and the operating theatre by providing real-time information about their clinical condition. Many of these patients develop systemic sepsis, which may lead to multiple organ failure.
Current technologies, such as continuous cardiac output monitoring or measurement of blood lactate concentrations, do not adequately reflect changes at cellular level. Systemic sepsis is characterized by disturbances in cellular metabolism, including a transition from aerobic (oxygen-using)to anaerobic (non oxygen-using) metabolism. Abnormal metabolism inevitably results in changes in the blood concentrations of many metabolic products.
Small molecules diffuse from the blood into the lungs and are present in exhaled breath. It has been demonstrated that many chemical products of cellular metabolism can be detected in exhaled breath as Volatile Compounds (VCs), using mass spectrometry (MS) as the detection method. It is not known how the pattern of these VCs changes in sepsis or other critical illness.
Ammonia is involved in many physiological and metabolic processes and can be used to monitor a number of conditions such as kidney and liver disorders. The potential use of breath ammonia as a non-invasive biomarker enabling metabolic information of a patient’s disease is a challenging area where Mass spectrometry (MS) is a new method of monitoring and may have a clinical utility in Critical care medicine.
We propose to use MS to measure ammonia and the exhaled concentrations of an array of VCs in 13 healthy volunteers capable of intense exercise.This information may be applicable in the future development of a novel bedside monitor for use in critically-ill patients.
Summary of Results
Exhaled ammonia and other volatile compounds following intense exercise in healthy volunteers.
We would like to thank all study participants. Unfortunately this study was terminated early due to local issues unrelated to the protocol and recruitment.
The research group consisted of Clinical Scientists and Anaesthetists . The study was undertaken within a clinical area at Manchester University Hospitals NHS Foundation Trust (MFT), Oxford Road, Manchester and sponsored by MFT.
It was linked to a previous study titled: Volatile organic compounds (VOCs) in exhaled breath during aerobic and anaerobic exercise in healthy volunteers: a metabolomics study (https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.1093%2Fbja%2Faew382&data=05%7C02%7Ccambsandherts.rec%40hra.nhs.uk%7Cd6fca605514345d4e7fc08dcd6589e13%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638620923321130458%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=jbIKBcR8C1mX%2BT8hpWiCz%2BoFGI5h%2FWWj0rgzYf6TB7I%3D&reserved=0) which demonstrated changes in the exhaled concentrations of several VOCs. In this study, it was hypothesized that intense exercise causes cells to metabolize abnormally resulting in specific changes to the VOCs that can be detected in breath-by-breath measurements and measured using a very sensitive monitor called a mass spectrometer. Several of these VOCs can serve as markers of health and one of which , ammonia, is a VOC which has been linked to disease states relating to the breakdown of proteins in major organs, similar to what happens to cells within major organs during severe infections. We asked healthy volunteers who were used to exercising beyond their lactate threshold i.e. at high levels of intensity, to cycle at increasing levels to their limit whilst being monitored by a breathing tube attached to a mass spectrometer and simultaneously , a device which measured oxygen consumption and carbon dioxide production. The high level of exercise acted as a trigger for cells to release intracellular ammonia and was detected by the mass spectrometer at low detectable levels.A total of three volunteers completed the study before it was terminated. These results will be used in the next phase of clinical studies which will monitor patients at the bedside.
REC name
East of England - Cambridgeshire and Hertfordshire Research Ethics Committee
REC reference
19/EE/0132
Date of REC Opinion
14 Jun 2019
REC opinion
Further Information Favourable Opinion