Estimation of Central Venous Pressure Using Cardiac Ultrasound of Inferior Vena Cava in Ventilated Children: A Prospective Multicenter Observational Study

Background: Although ultrasound (US) parameters of the inferior vena cava (IVC) cannot be used to estimate central venous pressure (CVP) in adults under mechanical ventilation (MV), the limited pediatric literature reports highly contradictory results. Pediatric evidence was awaited. Methods: This prospective, multicenter, observational study, conducted in six pediatric intensive care units, included children aged 2 days to 12 years who were under MV and had a central venous catheter in the superior vena cava to monitor CVP. US measurements were performed by experienced intensivists in order to calculate the following parameters: i) IVC-Collapsibility: [(IVCdmax - IVCdmin)/IVCdmax] x 100, ii) IVC-Distensibility: [(IVCdmax - IVCdmin)/IVCdmin] x 100, iii) IVC/Aortic: (IVCdmax/Ao) x 100. The search for correlation was studied using scatter plot and Pearson and Spearman's correlation tests for linear and monotonic relationships, respectively. Results: We included 120 children with a median age of 11.5 [2.0; 46.3] months and a median weight of 9.0 [5.0 ;15.0] kg. A third of the patients were admitted for post-operative care, including cardiac surgery, and a fourth for respiratory failure, with a median CVP of 7.5 [5.0; 10.3] mmHg at inclusion. No significant relationship was found between CVP and IVC-Collapsibility (Pearson r = -0.05, p = 0.55; Spearman r = -0.09, p = 0.32), IVC/Ao (Pearson r = 0.16, p = 0.08; Spearman r = 0.17, p = 0.06), or IVC-Distensibility (Pearson r = -0.003, p = 0.97; Spearman r = -0.09, p = 0.29). Conclusion: There is no correlation between CVP and IVC-US parameters in children under MV.