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Disturbances in renal cortical perfusion with reference to the microsphere technique
1Department of Anaesthesiology and Intensive Care, University Hospital, Uppsala, Sweden.
Acta Anaesthesiologica Scandinavica
|August 1, 1990
Summary
The microsphere technique for measuring renal blood flow may be invalid. Injecting fluids into the left atrium caused transient decreases in blood flow and oxygenation, questioning the method's accuracy.
Area of Science:
- Physiology
- Nephrology
- Medical Devices
Background:
- The microsphere technique is commonly used to measure regional blood flow.
- Accurate measurement of renal blood flow is crucial for understanding kidney function.
Purpose of the Study:
- To investigate the validity of the microsphere technique for assessing superficial renal cortical blood flow.
- To evaluate the impact of fluid injections on renal blood flow and oxygenation.
Main Methods:
- Anesthetized pigs were used for the study.
- Superficial renal cortical blood flow was measured using laser Doppler flowmetry.
- Tissue oxygenation was measured using an oxygen surface electrode technique.
Main Results:
- Injecting small volumes of plasma or saline into the left atrium caused rapid, transient decreases in renal cortical blood flow and oxygenation.
- These decreases occurred even when microspheres were not used and were not affected by injectate temperature.
- The timing of these decreases raised concerns about the accuracy of microsphere-based flow measurements.
Conclusions:
- The microsphere technique's validity for measuring superficial renal cortical blood flow is questionable due to transient flow reductions caused by injections.
- Further methodological studies are needed to refine or validate blood flow measurement techniques in the renal cortex.
