Ultrasonic cardiac output monitor for predicting volume responsiveness in children with septic shock

Objective To assess the role of ultrasonic cardiac output monitor (USCOM) in predicting the volume responsiveness of children with septic shock. Methods The study was performed with prospective, observational cohort study method.Twenty-one mechanically ventilated children with septic shock were included.All children were treated with volume expansion (VE) test.Hemodynamic indicators such as stroke volume (SV), stroke volume index (SVI), cardiac index (CI), stroke volume index (SVI), systemic vascular resistance index (SVRI) and stroke volume variation (SVV) were measured by USCOM before and after each test.Based on the responsiveness of VE (children were considered to be responders to VE if SV increased≥10%), the sick children were divided into responsive group and non-responsive group, respectively.The comparisons between these 2 sorts of children were assessed by using t-test or χ2 test.The roles of SVV, central venous pressure (CVP) before fluid administration in predicting vo-lume responsiveness were evaluated by receiver operating characteristic curve (ROC). Results A total of 23 VE tests in 21 patients were evaluated and 13 responders and 10 non-responders were identified.There was no significant diffe-rence in the clinical data at incipient stage between 2 groups.Before VE test, the SVV was higher in responders in comparison with non-responders(P=0.003), and the CVP was not significantly different between the 2 groups(P>0.05). The area under the ROC curve (AUC) of SVV to predict volume responsiveness was 92.4% [95% confidence interval (95% CI): 0.821-1.000, P=0.001], the SVV>17.5% showed 75.0% of sensitivity and 81.8% of specificity for predicting volume responsiveness. The AUC of CVP to predict volume responsiveness was 92.4% (95% CI: 0.206-0.710, P=0.742), the CVP<5.5 cm H2O(1 cm H2O=0.098 kPa) was predictive of response to VE with a sensitivity of 41.7% and a specificity of 60.0%. Conclusions SVV measured by USCOM can predict the volume responsiveness in mechanically ventilated patients with septic shock fluid therapy, and it is more reliable than traditional indicators such as CVP and others in guiding fluid therapy for children. Key words: Ultrasonic cardiac output monitor; Volume expansion; Stroke volume variation; Septic shock