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Published on: January 20, 2023
Effect of tidal volume change on pressure-based prediction of fluid responsiveness in children
Sang-Hwan Ji1, Young-Eun Jang1, Jung-Bin Park1
1Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
Insights
Increasing tidal volume does not improve the ability of pulse pressure variation or systolic pressure variation to predict fluid responsiveness in children undergoing cardiac surgery. These dynamic parameters remain unreliable for guiding fluid therapy in pediatric patients.
Area of Science:
- Pediatric Anesthesiology
- Critical Care Medicine
- Cardiovascular Surgery
Background:
- Pulse pressure variation (PPV) and systolic pressure variation (SPV) are dynamic indicators used to predict fluid responsiveness in adults.
- Previous studies indicate PPV and SPV are unreliable in children.
- Augmenting tidal volume in adults improves the predictive capability of PPV and SPV.
Purpose of the Study:
- To investigate if increasing tidal volume can enhance the predictive value of PPV and SPV for fluid responsiveness in children.
- To assess the reliability of augmented PPV and SPV in pediatric cardiac surgery patients.
Main Methods:
- Prospective study involving children under 7 years undergoing atrial or ventricular septal defect repair.
- PPV and SPV were recorded at tidal volumes of 6, 10, and 14 mL/kg.
- Fluid responsiveness was assessed by a 15% increase in stroke volume index (measured via transesophageal echocardiography) after 10 mL/kg crystalloid bolus.
Main Results:
- Twenty-six children were included; 15 were responders.
- At a tidal volume of 14 mL/kg, the area under the ROC curves for PPV and SPV were 0.576 (p=0.517) and 0.548 (p=0.678), respectively.
- No significant differences in dynamic parameters were observed between responders and nonresponders.
Conclusions:
- Augmented PPV and SPV, even at increased tidal volumes, cannot reliably predict fluid responsiveness in children after simple cardiac surgery.
- Differences in arterial compliance and thoracic wall compliance may explain the ineffectiveness in children compared to adults.
Introduction:
It is known that pulse pressure variation and systolic pressure variation cannot predict fluid responsiveness in children. In adults, the ability of these dynamic parameters to predict fluid responsiveness is improved by increasing tidal volume. We planned to investigate whether pulse pressure variation or systolic pressure variation can predict fluid responsiveness in children when augmented by increasing tidal volume by conducting a prospective study.
Methods:
We enrolled children younger than 7 years who underwent cardiac surgery for atrial septal defect or ventricular septal defect. After sternum closure, pulse pressure variation and systolic pressure variation were continuously recorded while changing the tidal volume to 6, 10, and 14 mL/kg. Fluid loading was done with 10 mL/kg of crystalloids for 10 min, and stroke volume index was measured via transesophageal echocardiography. Children whose stroke volume index increased by more than 15% after the fluid loading were defined as responders to fluid therapy. We set primary outcome as the predictability of pulse pressure variation and systolic pressure variation for fluid responsiveness and measured the area under the curve of receiver operating characteristics curve.
Results:
Twenty-six children were included, of which 15 were responders. At the tidal volume of 14 mL/kg, the area under the curves of receiver operating characteristics curves of pulse pressure variation and systolic pressure variation were 0.576 (p = .517) and 0.548 (p = .678), respectively. The differences in dynamic parameters between responders and nonresponders were not significant.
Discussion:
Failure of pulse pressure variation or systolic pressure variation at augmented tidal volume in children may be due to difference in their arterial compliance from those of adults. Large compliance of thoracic wall may be another reason.
Conclusions:
Augmented pulse pressure variation or systolic pressure variation due to increased tidal volume cannot predict fluid responsiveness in children after simple cardiac surgery.
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