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Stroke volume variation during acute normovolemic hemodilution.
Gudrun Kungys1, David D Rose, Neal W Fleming
1Department of Anesthesiology and Pain Medicine, University of California Davis, Davis, California, USA.
Anesthesia and Analgesia
|November 20, 2009
Summary
Stroke volume variation (SVV) measured by the FloTrac/Vigileo system effectively tracks changes in intravascular volume during acute normovolemic hemodilution. This method correlates with 3D transesophageal echocardiography (TEE) left ventricular (LV) volume, suggesting its utility in fluid management.
Area of Science:
- Anesthesiology
- Critical Care Medicine
- Cardiovascular Physiology
Background:
- Optimizing intravascular volume in surgical patients is crucial to prevent complications from fluid imbalances.
- Acute normovolemic hemodilution (ANH) is a technique used during surgery that requires careful fluid management.
- Monitoring changes in cardiac output and fluid status is essential during ANH.
Purpose of the Study:
- To investigate if stroke volume variation (SVV) from an arterial pressure-based cardiac output (CO) monitor (FloTrac/Vigileo) reflects volume changes during ANH.
- To evaluate the correlation between SVV and 3D transesophageal echocardiography (TEE) left ventricular (LV) volumes during ANH.
Main Methods:
- Twenty-five patients undergoing ANH were studied.
- Measurements of CO and SVV were taken at baseline, after blood removal (5%, 10%, 15% estimated blood volume [EBV]), and after replacement with hetastarch to -10%, -5%, and baseline EBV.
- 3D TEE was used to measure LV end-diastolic and end-systolic volumes at each timepoint.
Main Results:
- SVV significantly increased from 9.2% to 20.3% (P < 0.001) after 15% EBV removal and returned to 7.2% after replacement.
- Indexed LV end-diastolic volume decreased from 42.1 to 36.9 mL/m² (P < 0.001) after 15% EBV removal and returned to 45.9 mL/m² after replacement.
- SVV measurements showed an inverse correlation with 3D TEE LV volume measurements.
Conclusions:
- SVV measured by the FloTrac/Vigileo system significantly changes during blood removal and replacement in ANH.
- These SVV changes correlate with LV volume variations assessed by 3D TEE.
- SVV shows potential as a tool for guiding intravascular volume optimization during surgery.
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