Respiratory Variation in Aortic Blood Flow Velocity as a Predictor of Fluid Responsiveness in Children After Repair of Ventricular Septal Defect

Abstract

This study aimed to compare respiratory variation in transthoracic echo-derived aortic blood flow velocity (∆Vpeak) and inferior vena cava diameter (∆IVCD) with central venous pressure (CVP) as predictors of fluid responsiveness in children after repair of ventricular septal defect (VSD). A prospective study conducted in pediatric intensive care unit investigated 21 mechanically ventilated children who had undergone repair of VSD. Standardized volume replacement (VR) was the intervention used. Hemodynamic measurements including CVP, heart rate, mean arterial pressure, transthoracic echo-derived stroke volume (SV), cardiac output, ∆Vpeak, and ∆IVCD were performed 1 h after patient arrival in the intensive care unit. Hemodynamic measurements were repeated 10 min after VR by an infusion of 6% hydroxyethyl starch 130/0.4 (10 ml/kg) over 20 min. The volume-induced increase in the SV was 15% or more in 11 patients (responders) and less than 15% in 10 patients (nonresponders). Before volume replacement, the ∆Vpeak (23.1 ± 5.7% vs. 14.0 ± 7.7%; p = 0.006) and ∆IVCD (26.5 ± 16.2% vs. 9.2 ± 9.1%; p = 0.008) was higher in the responders than in the nonresponders, whereas CVP did not significantly differ between the two groups. The prediction of fluid responsiveness was higher with the ΔVpeak, as shown by a receiver operating characteristic curve area of 0.83 (95% confidence interval [CI], 0.61-1.00; p = 0.01), a ΔIVCD of 0.85 (95% CI, 0.69-1.00; p = 0.01), and a CVP of 0.48 (95% CI, 0.22-0.73; nonsignificant difference). The ∆Vpeak and ∆IVCD measured by transthoracic echocardiography can predict the response of SV after volume expansion in mechanically ventilated children at completion of VSD repair.

Advanced Hemodynamic Monitoring in Critically Ill Children

“…64 In small children, variation in blood-flow velocity in the aorta using echocardiography can serve as a surrogate for arterial pressure variations. 52,53 Arterial pressure variations are a reliable indicator of fluid responsiveness in adults. 51,65,66 However, reliability decreases with spontaneous respiration, nonsinus rhythm, pulmonary hypertension, right heart failure, low tidal volume, or open-chest conditions.…”

“…Results from adult and pediatric studies have shown that only up to half of the fluid challenges increase SV. [51][52][53] To avoid unnecessary fluid overload, there is a great interest in predicting fluid responsiveness. Both static and dynamic parameters are used for this purpose.…”

“…Indeed, CVP does not predict fluid responsiveness and only poorly reflects preload in adults, children, and pediatric animal models. 6,19,20,26,52,55,56 The other static measure is GEDVI, which is measured by using the transpulmonary thermodilution technique incorporated in the PiCCO device (Pulsion, Munich, Germany). GEDVI is a virtual blood volume measurement that includes the end-diastolic volumes of left and right atria and ventricles, but it also includes the volume of central veins and aorta between the point of injection and the point of detection of the indicator.…”

Intraoperative fluid therapy in neonates

“…Studies in infants and neonates have shown that fluid responders did not have an associated rise in blood pressure. 65,[69][70][71][72] Monitors of end organ perfusion have been used to titrate fluid therapy. Near infrared spectroscopy (NIRS) has shown that a systolic blood pressure fall of 37% from baseline is associated with significant cerebral desaturation.…”

Pulse oximeter plethysmograph variation and its relationship to the arterial waveform in mechanically ventilated children

“…Dynamic preload indicators, such as arterial pulse pressure variation (DPP), are variables that quantify the effects of mechanical ventilation on cardiac stroke volume, and have been shown in adults to predict VR [5][6][7]. Pediatric studies examining dynamic preload indicators [8][9][10][11] have found that respiratory variations in aortic blood flow predict VR in children.…”