Correlation between variation of aortic peak blood flow velocity, inferior vena cava diameter variation and stroke volume variation in children

Background: Non-invasive monitoring using ultrasound or Doppler assists in quick haemodynamic assessment and helps to improve outcomes in critical care. Parameters including aortic peak blood flow velocity variation (ΔVpeak), inferior vena cava diameter variation (ΔIVC) and stroke volume variation (SVV) have been commonly used in children. Objectives: The aim of this study was to assess the correlations between ΔVpeak from transthoracic echocardiography, ΔIVC from abdominal ultrasound and SVV from ultrasonic cardiac output monitoring. Settings and Design: A prospective observational cohort study was undertaken in the paediatric intensive care unit in a tertiary university hospital. Methods: ΔVpeak, ΔIVC and SVV were measured in mechanically ventilated children using ultrasound- or Doppler-based monitoring. Statistical Analysis Used: Pearson correlation coefficient was computed to assess the relationship. Results: A convenient sample of 55 patients with a median age of 31 months (range 6 months to 5 years) was enrolled. ΔVpeak, ΔIVC and SVV showed significant positive correlations between the three variables, i.e., ΔVpeak and ΔIVC (r = 0.415 with P = 0.002), ΔVpeak and SVV (r = 0.539 with P < 0.001) and ΔIVC and SVV (r = 0.524 with P < 0.001). Conclusions: In mechanically ventilated children, there is a positive correlation between ΔVpeak, ΔIVC and SVV. ΔVpeak and SVV provided the best, though moderate, correlation.