Identification of volume parameters monitored with a noninvasive ultrasonic cardiac output monitor for predicting fluid responsiveness in children after congenital heart disease surgery

No previous study has used an ultrasonic cardiac output monitor (USCOM) to assess volume parameters, such as stroke volume variation (SVV), in order to predict the volume status and fluid responsivenes in children after congenital heart disease (CHD) surgery. The present prospective trial aimed to investigate the ability of SVV and corrected flow time (FTc), which were assessed with a USCOM, for predicting fluid responsiveness in children after CHD surgery. The study included 60 children who underwent elective CHD surgery. Data were collected after elective CHD surgery. After arrival at PICU, the continuous invasive blood pressure was monitored. Once the blood pressure (BP) decreased to the minimum value, 6% hydroxyethyl starch (130/0.4) was administered (10 mL/kg) over 30 minutes for volume expansion (VE). The USCOM was used to monitor the heart rate, central venous pressure, stroke volume index (SVI), cardiac index, SVV, FTc of the children before and after VE. Additionally, the SVI change (ΔSVI) was calculated, and the inotropic score (IS) was determined. Children with a ΔSVI ≥15% were considered responders, while the others were considered nonresponders. The children were also divided into IS ≤10 and IS >10 groups. Of the 60 children, 32 were responders and 28 were nonresponders. We found that only SVV was significantly correlated with ΔSVI (r = 0.42, P < .01). SVV could predict fluid responsiveness after surgery (area under the curve [AUC]: 0.776, P < .01), and the optimal threshold was 17.04% (sensitivity, 84.4%; specificity, 60.7%). Additionally, the SVV AUC was higher in the IS >10 group than in the IS ≤10 group (0.81 vs 0.73). SVV measured with a USCOM can be used to predict fluid responsiveness after CHD surgery in children. Additionally, the accuracy of SVV for predicting fluid responsiveness might be higher among patients with an IS >10 than among those with an IS ≤10.