Mechanical ventilation in a conscious male during exercise

A case report

authored by: Sarah Anne Angus, Joshua L Taylor, Leah Mann, Alex Williams, Eric J Stöhr, Jason S Au, Andrew William Sheel, Paolo B Dominelli
Abstract: We recently explored the cardiopulmonary interactions during partial unloading of the respiratory muscles during exercise. Expanding upon this work, we present a noteworthy case study whereby we eliminated the influence of respiration on cardiac function in a conscious but mechanically ventilated human during exercise. This human was a young healthy endurance-trained male who was mechanically ventilated during semi-recumbent cycle exercise at 75 Watts (W) (~30% Wmax). During mechanically ventilated exercise, esophageal pressure was reduced to levels indistinguishable from the cardiac artefact which led to a 94% reduction in the work of breathing. The reduction in respiratory pressures and respiratory muscle work led to a decrease in cardiac output (-6%), which was due to a reduction in stroke volume (-13%), left ventricular end-diastolic volume (-15%) and left-ventricular end-systolic volume (-17%) that was not compensated for by heart rate. Our case highlights the influence of extreme mechanical ventilation on cardiac function while noting the possible presence of a maximal physiological limit to which respiration (and its associated pressures) impacts cardiac function when the work of breathing is maximally reduced.
Organisation(s): Institute of Sports Science
External Organisation(s): University of Waterloo
University of British Columbia
Columbia University Irving Medical Center
Type: Article
Journal: Applied Physiology, Nutrition and Metabolism
Volume: 49
Pages: 1436 - 1440
No. of pages: 5
ISSN: 1715-5312
Publication date: 10.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Physiology (medical), Nutrition and Dietetics, Physiology, Endocrinology, Diabetes and Metabolism
Sustainable Development Goals: SDG 3 - Good Health and Well-being
Electronic version(s): https://doi.org/10.1139/apnm-2024-0100 (Access: Closed)