Noninvasive tissue oxygen saturation measurements identify supply dependency
Mark E George1, Greg J Beilman, Kristine E Mulier
1Department of Surgery, University of Minnesota, Minneapolis, Minnesota 55455, USA.
The Journal of Surgical Research
|July 11, 2009
Summary
Noninvasive tissue oxygen saturation (StO(2)) measurements accurately reflect oxygen delivery during hemorrhagic shock. This method is reliable across various physiological conditions, aiding in patient outcome prediction.
Area of Science:
- Physiology
- Biomedical Engineering
- Critical Care Medicine
Background:
- Hemorrhagic shock can cause multi-organ failure and death.
- Noninvasive tissue oxygen saturation (StO(2)) predicts outcomes in hemorrhagic shock.
- Accurate monitoring of tissue oxygenation is crucial for managing shock.
Purpose of the Study:
- Compare invasive and noninvasive measurements of tissue hemoglobin oxygenation.
- Evaluate the impact of shock-related physiological conditions on tissue oxygenation.
Main Methods:
- Pigs were subjected to controlled shock models (hypothermia, hemodilution, vascular tone changes).
- Invasive and noninvasive measurements of StO(2), hemodynamics, and blood gases were obtained.
- Baseline and experimental values were recorded in hind limb tissues.
Main Results:
- Tissue hemoglobin oxygenation remained stable across physiological temperature ranges.
- Supply-dependent oxygen consumption was observed at low oxygen levels (<7 mL O(2)/min/kg).
- Noninvasive StO(2) correlated with oxygen delivery and supply-dependent consumption under shock conditions.
Conclusions:
- Noninvasive StO(2) measurements are valid and reliable across diverse physiological conditions.
- StO(2) correlates with invasively measured oxygen delivery.
- Noninvasive StO(2) monitoring is a valuable tool in managing hemorrhagic shock.
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