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

Abstract

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.

Fluid responsiveness in the pediatric population

“…An ultrasonic cardiac output monitor (USCOM; USCOM Ltd., Australia) is a noninvasive, continuous-wave Doppler monitor that can be used to measure cardiac output via a probe applied to the suprasternal notch. SVV measured with USCOM can be used to predict fluid responsiveness after congenital heart surgery in children [35]. However, the issue of mathematical coupling should be considered because the cardiac output is calculated using the stroke volume obtained from USCOM.…”

“…However, the issue of mathematical coupling should be considered because the cardiac output is calculated using the stroke volume obtained from USCOM. Additionally, the accuracy of SVV for predicting fluid responsiveness was reported to be higher among patients with inotropic score > 10 than among those with inotropic score ≤ 10 [35] (Table 1). In addition, in another study, cardiac output measurements using USCOM in children did not reliably represent absolute cardiac output values as compared with measurements using the thermodilution technique with a pulmonary artery catheter [36].…”

Diagnostic accuracy of stroke volume variation for predicting fluid responsiveness in children undergoing cardiac surgery: A systematic review and meta‐analysis

“…All included studies were published from 2011 to 2017, with a mean sample size of 42 in the 6 studies (range from 26 to 60) and 251 pediatric patients. In studies included in our meta‐analysis, diagnoses of FR by SVV were performed based on pulse index continuous cardiac output (PiCCO Plus ® , Version 6.0, Pulsion Medical Systems, Munich, Germany), 14 ultrasonic cardiac output monitor (USCOM, Sydney, Australia), 21 noninvasive cardiac output monitor (NICOM, Cheetah Medical, Wilmington, DE, USA), 1 or/and a transesophageal echocardiogram (TEE, Philips iE33 and Cardio QP TM , Deltex Medical TM , Chichester, UK 3,22 monitoring device. In these included studies, all patients were sedated and ventilated with tidal volumes (TVs) of 8–10 ml/kg 23 .…”

“…Volume therapy for the patients used crystalloids or colloids. Two studies used multiple liquids (crystalloid or colloid) 3,22 as fluid boluses, three studies 1,2,14 used colloids as a fluid bolus, and one study 21 used 6% hydroxyethyl starch (130/0.4). Six studies were performed in the intensive care unit after congenital heart surgery.…”

“…Six studies were performed in the intensive care unit after congenital heart surgery. In five studies, a change in SVV of at least 15% for FR was defined as a threshold, 1,14,21,22,24 except for one study that used a cutoff of 17% 3 . We used QUADAS‐2 to assess the quality of all studies, which is detailed in Figure 1.…”