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The predictive value of the Pleth Variability Index on fluid responsiveness in spontaneously breathing anaesthetized
Frank Weber1, Bharat K Rashmi1, Gülhan Karaoz-Bulut1
1Department of Anesthesiology, Erasmus University Medical Center, Sophia Children's Hospital, Rotterdam, The Netherlands.
Insights
The Pleth Variability Index (PVI) can help predict fluid responsiveness in spontaneously breathing anesthetized children. However, a definitive cutoff value for PVI is not yet established due to overlapping values in responders and non-responders.
Area of Science:
- Pediatric Anesthesiology
- Critical Care Medicine
- Hemodynamic Monitoring
Background:
- Preoperative hydration status is crucial for children undergoing anesthesia.
- Routine fluid replacement during induction may not account for individual fluid status.
- Accurate assessment of fluid responsiveness is essential for optimal perioperative management.
Purpose of the Study:
- To evaluate the predictive value of the Pleth Variability Index (PVI) for fluid responsiveness in spontaneously breathing anesthetized children.
- To determine if PVI can guide fluid administration in this pediatric population.
Main Methods:
- Fifty pediatric patients under 6 years old were studied during anesthesia induction.
- Pleth Variability Index, stroke volume, cardiac index, blood pressure, and heart rate were measured.
- Fluid responsiveness was defined as a ≥10% increase in stroke volume after fluid administration or passive leg raising.
Main Results:
- PVI was significantly higher before fluid administration in fluid-responsive patients compared to non-responders (21.4% vs 15.3%).
- PVI decreased during fluid administration and passive leg raising in fluid responders.
- The area under the ROC curve for PVI predicting fluid responsiveness was 0.781, with optimal sensitivity (82%) and specificity (70%) at a PVI >15%.
Conclusions:
- The Pleth Variability Index shows potential as an additional tool for predicting fluid responsiveness in spontaneously breathing anesthetized children.
- A reliable cutoff value for PVI could not be established due to significant overlap between fluid responders and non-responders.
- Further research is needed to refine the use of PVI in pediatric fluid management.
Background:
In children, the preoperative hydration status is an important part of the overall clinical assessment. The assumed preoperative fluid deficit is often routinely replaced during induction without knowing the child's actual fluid status.
Aim:
We investigated the predictive value of the Pleth Variability Index as a measure of fluid responsiveness in spontaneously breathing anesthetized children.
Methods:
Pleth Variability Index, stroke volume and Cardiac Index, measured by electrovelocimetry, mean blood pressure, and heart rate were recorded during anesthesia induction in 50 pediatric patients <6 years. Baseline values were compared to values recorded after administration of 10 mL/kg of Ringer's lactate and during two passive leg raising tests (before and after fluid administration). Fluid responsiveness was defined as an increase of ≥10% in stroke volume.
Results:
Only in fluid responsive patients, Pleth Variability Index values were higher before fluid administration than thereafter (21.4 ± 5.9% vs 15.0 ± 9.4%, 95% CI of difference 1.1 to 11.8%, P = .02). Pleth Variability Index values at baseline were higher in fluid responders (21.4 ± 5.9%) than in fluid nonresponders (15.3 ± 7.7%), 95% CI of difference 1.6 to 10.6%, P = .009. The area under the receiver operating curve indicating fluid responsiveness was 0.781 (95% CI 0.623 to 0.896, P = .0002), with the highest sensitivity (82%) and specificity (70%) at a Pleth Variability Index of >15% (Positive predictive value 2.71 (95% CI: 1.4 to 5.2)). Only in fluid responders, the Pleth Variability Index decreased during passive leg raising, while stroke volume increased.
Conclusions:
The Pleth Variability Index may be of additional value to predict fluid responsiveness in spontaneously breathing anesthetized children. A significant overlap in baseline Pleth Variability Index values between fluid responsive and nonfluid responsive patients does not allow a reliable recommendation as to a cut off value.
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