When a person enters cardiac arrest, chest compressions are typically performed over the midpoint of the sternum. For every minute that CPR efforts are delayed, the chances of survival decrease by 10 per cent.
"As a paramedic, resuscitation is very personal to me,” said Marshall.
“From delivering CPR, I have firsthand experience in the impact high quality CPR can make in a patient’s outcome. Even small improvements in how we do CPR gives patients the best chance at survival.”
Marshall’s Western College of Medicine (WCVM) research team tested if the placement of chest compressions could influence the amount of blood – and therefore, oxygen – pumped to the brain. Blood flow to the brain is vitally important for survival and recovery following a cardiac incident.
“It started as this simple, but abstract idea that maybe we can improve the quality of CPR by pumping more of the heart and not the chest.”
Using ultrasound technology to measure brain blood flow, the team found that performing compressions over the left ventricle of the heart – as opposed to over the sternum – increased the amount of blood pumped by the heart and, most importantly, to the brain.
This is the first research to demonstrate the effects of chest compression location on the amount of blood flow to the brain.
“If performing chest compressions over top of the left ventricle of the heart can increase the pumping capacity of the heart and blood flow to the brain during CPR, then it is likely that survival rates and quality of life for survivors will be improved,” said Marshall of the importance of the discovery.
This new knowledge could lead to more lives saved and improved recoveries for patients following a cardiac episode.
Marshall presented his work at the USask Veterinary Biomedical Sciences Graduate Symposium and the USask Life and Health Sciences Research Expo in 2021. He has also been invited to present the findings at the 2021 Canadian Resuscitation Outcomes Consortium National Assembly – the premier resuscitation conference in Canada.
In the future, Marshall hopes to investigate if and how left ventricle chest compressions could improve neurological outcomes for patients and move his work into a human clinical trial stage.
He plans to continue to conduct research on patient-centered care in an emergency health environment and hopes to return to graduate school to earn his doctorate.
“This work could have major implications for the future of CPR on the international stage,” said Marshall.
“Generating an opportunity for more people to survive and recover from cardiac arrest drives me to keep moving forward.”
Marshall successfully defended his thesis and received his Master of Science degree in Biomedical Science from the WCVM in July 2021. His research was supervised by Dr. Dylan Olver (PhD), an assistant professor in veterinary biomedical sciences.
“The opportunity to be involved in developing a better healthcare system for the public inspires me. Whether it is adaptation to treatment or a novel practice, striving to constantly improve the healthcare available to the public is what motivates me.”
The research has been funded by the USask Devolved Scholarship, the Canadian Resuscitation Outcomes Consortium Student Funding Grant program and the Saskatchewan Health Research Foundation.