Measuring Tissue Perfusion and PO2 in Conscious Animals to Investigate Organ Failure

Measuring Tissue Perfusion and PO2 in Conscious Animals to Investigate Organ Failure

Scientists present ground breaking research in models of Acute Kidney Injury (AKI). Methods used to gather these insights are made possible using the latest in fibre optic sensing technology to obtain dissolved oxygen and microvascular blood perfusion at the tissue level.

The survival of tissues and organs relies on an adequate supply of oxygen which is distributed together with nutrients and signal molecules via microvascular blood perfusion. Tissue oxygen tension (ptiO2) is a readout of oxygen availability at the cellular level representing the balance between oxygen supply and metabolic oxygen consumption. in addition, the measurement of microvascular blood perfusion provides critical information for research applications where blood supply has been disrupted. Combining these measurements gives the researcher a very powerful and unique tool to answer questions in the areas of physiology, oncology, cerebral monitoring, ischemia/reperfusion, ophthalmology and many more.

During this webinar, sponsored by Scintica Instrumentation, Professor Clive May and Dr. Yugeesh Lankadeva, from the Florey Institute of Neuroscience and Mental Health in Melbourne, discuss their research using Oxford Optronix OxyFlo™ and OxyLite™ tissue vitality monitoring systems to investigate the causes of acute renal failure in large animal models, the effects of resuscitation with volume or vasopressor drugs on renal perfusion and oxygenation in sepsis, and the measurement of bladder urinary pO2 as a real-time estimate of renal medullary ptiO2.

First, they present the development and validation of methodology to measure renal cortical and medullary tissue perfusion and oxygenation long-term in conscious animals. Specifically, they review selective changes in renal cortical and medullary tissue perfusion and oxygenation in response to alterations in total organ blood flow and administration of drugs.

In addition, Professor May and Dr. Lankadeva share data from their studies demonstrating changes in total renal blood flow, renal function and differential changes in renal cortical and medullary perfusion, and pO2 during resuscitation and in models of sepsis. They conclude the presentation with a focus on why the study of septic acute kidney injury is so important.

To download a PDF copy of the presentation, click on the “LinkedIn SlideShare” icon located in the bottom-right corner of the slide-viewer. From the SlideShare landing page click the “Download” button to retrieve the file.

Presentation Details:

  • 00:00 – 01:51: Webinar Introduction
  • 01:51 – 04:22: Importance of Measuring Tissue Perfusion and PO2 and Webinar Outline [C. May]
  • 04:22 – 09:48: Implantation of Renal Probes to Measure Tissue Perfusion and PO2 [C. May]
  • 09:48 – 13:22: Validation Studies for Long-Term Stability and Renal Artery Occlusion [C. May]
  • 13:22 – 17:17: Preclinical Studies on the Effect of Sepsis on Intrarenal Perfusion and Oxygenation [C. May]
  • 17:17 – 32:07: Preclinical Studies on Changes During Resuscitation With Noradrenaline and Angiotensin II [Y. Lankadeva]
  • 32:07 – 35:39: Measurement of Brain Perfusion and PO2 [C. May]
  • 35:39 – 37:58: Summary [C. May]
  • 37:58 – 51:26: Presenter Q&A Session

To download a PDF copy of the presentation, click on the “LinkedIn SlideShare” icon located in the bottom-right corner of the slide-viewer. From the SlideShare landing page click the “Download” button to retrieve the file.

Clive May, Ph.D.

Professor
Florey Institute of Neuroscience and Mental Health

Professor Clive May is head of the Pre-clinical Critical Care Unit at the Florey Institute of Neuroscience and Mental Health. Using his expertise in cardiovascular, renal, and neuro-physiology he has created a sophisticated large animal operative and critical care unit. This unit creates and supports relevant pre-clinical models of critical illness and injury, including septic shock, heart failure, myocardial infarction and cardiopulmonary bypass. These pre-clinical models enable exploration of the pathophysiology of critical illness and provide the opportunity to develop new therapeutics, biomarkers and devices ready for clinical testing in critically ill patients. Current studies in the Pre-clinical Critical Care Unit are focussed on the development of novel therapies to maintain blood pressure and kidney function in septic shock, establishing optimal perfusion parameters to reduce kidney injury during cardiopulmonary bypass, new treatments for myocardial ischaemia reperfusion injury and development of a brain machine interface.

Yugeesh Lankadeva, Ph.D.

Research Fellow
Florey Institute of Neuroscience and Mental Health

Yugeesh Lankadeva, Ph.D., is a National Heart Foundation Future Leader Research Fellow in the Pre-clinical Critical Care Unit at the Florey Institute of Neuroscience and Mental Health. His research focuses on the mechanisms underlying cardiovascular failure, acute kidney injury and immunosuppression in sepsis and the development of acute kidney injury following cardiac surgery on cardiopulmonary bypass. Dr. Lankadeva is particularly interested in the neural and hormonal control of the circulation, from reactivity of isolated blood vessels to integrated physiological studies in the conscious whole animal. He has demonstrated that selective renal hypoxia occurs very early in sepsis and that this may contribute to the development of kidney injury. In addition, his demonstration that urinary PO2 changes in parallel with renal medullary PO2, suggests that this may be used as a novel biomarker for early detection of the development of kidney injury and to continuously estimate renal medullary tissue PO2 during administration of therapies used in intensive care units. His goal is to understand the pathological changes that occur during sepsis and during cardiac surgery on cardiopulmonary bypass and, armed with this knowledge, to develop improved therapies to reduce the development of acute kidney injury and cardiovascular failure.