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Updated: Jul 18, 2026
Adult and Pediatric Porcine Model of Acute Volume Overload
Published on: January 12, 2024
Variation in blood pressure as a guide to volume loading in children following cardiopulmonary bypass
Henry Tran1, Norbert Froese, Guy Dumont
1Department of Electrical & Computer Engineering, The University of British Columbia, Vancouver, V6H 3V4, Canada.
Insights
Blood pressure variation measures like systolic pressure variation (SPV) and systolic volume variation (SVV) better guide fluid loading in children post-cardiopulmonary bypass than central venous pressure (CVP). Delta down was not useful for predicting fluid responsiveness.
Area of Science:
- Pediatric critical care medicine
- Cardiovascular physiology
- Anesthesiology
Background:
- Intravascular volume loading is crucial for optimizing cardiac output in pediatric patients after cardiopulmonary bypass.
- Central venous pressure (CVP) is commonly used but often inaccurately predicts fluid responsiveness.
- Arterial pressure waveform variation is a potential alternative predictor, validated in adults.
Purpose of the Study:
- To compare blood pressure variation measures against CVP for guiding fluid administration in children post-cardiopulmonary bypass.
- To evaluate the efficacy of Systolic Pressure Variation (SPV), Pulse Pressure Variation (PPV), and Systolic Volume Variation (SVV) in predicting fluid responsiveness.
Main Methods:
- Continuous real-time measurements were collected from 25 children undergoing volume loading post-cardiopulmonary bypass.
- Systolic Pressure Variation (SPV), Pulse Pressure Variation (PPV), and Systolic Volume Variation (SVV) were calculated.
- Fluid responsiveness was defined as a blood pressure increase of ≥80 mmHg/L/m².
Main Results:
- Central venous pressure (CVP) demonstrated poor predictive performance for fluid responsiveness (AUC 0.58).
- Systolic Pressure Variation (SPV) and Systolic Volume Variation (SVV) showed superior predictive accuracy (AUC 0.74), outperforming CVP and Pulse Pressure Variation (PPV, AUC 0.67).
- A negative relationship was observed between blood pressure change and Delta Down, indicating its lack of utility.
Conclusions:
- Blood pressure variation measures, specifically SPV and SVV, are more effective guides for volume loading in pediatric patients post-cardiopulmonary bypass than CVP.
- Delta down is not a reliable predictor of fluid responsiveness in this patient population.
- Prospective clinical trials are recommended to further validate SPV and SVV.
Objective:
Intravascular volume loading is used to optimize cardiac output in children following weaning from cardiopulmonary bypass. Central venous pressure (CVP) is frequently used to titrate fluid administration but it is often misleading in predicting fluid responsiveness. Variation in the arterial pressure waveform is exaggerated in patients with deficient intravascular volume and has been shown to be a good predictor of fluid responsiveness in adults following cardiac surgery. The aim of this study was to compare the measures of variation in blood pressure as a guide to volume loading in children following cardiopulmonary bypass.
Methods:
After ethical approval, we collected continuous real-time measurements from 25 children during volume loading after cardiopulmonary bypass. Subjects with moderate or severe tricuspid incompetence or who did not require volume loading during weaning from cardiopulmonary bypass were excluded from the study. Unstable readings were excluded from analysis. Systolic Pressure Variation (SPV), Pulse Pressure Variation (PPV) and Systolic Volume Variation (SVV) were retrospectively calculated before and after each bolus of fluid. Fluid responsiveness was classified as a change in blood pressure of > or =80 mmHg/L/m(2).
Results:
Forty-four boluses were analyzed from the 25 children. Respiratory variables were similar. CVP was a poor predictor of fluid responsiveness and a negative relationship between change in blood pressure and Delta Down was observed. Performance in predicting fluid responsiveness as measured by the areas under the ROC curves were CVP (0.58), PPV (0.67), SPV (0.74) and SVV (0.74).
Conclusions:
Variation in blood pressure was a better guide to volume loading in children than CVP. Delta down was not useful in predicting fluid responsiveness in children with open chests following bypass surgery. SPV and SVV require further testing in prospective clinical trials.
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