Comparison of inferior vena cava collapsibility, distensibility, and delta indices at different positive pressure supports and prediction values of indices for intravascular volume status

Abstract

Background/aim: To compare the inferior vena cava (IVC) indices, identify their variation rates at positive pressure values and accuratepredictive values for the volume status in patients with spontaneous respiration receiving different positive pressure support.Material and methods: The study included 100 patients who were divided into 4 pressure support groups, according to the differentpressure supports received, and 3 volume groups according to their CVP values. Ultrasonography was applied to all of the patients todefine their IVC diameters at different pressure supports. Dynamic parameters were derived from the ultrasonographic assessment ofthe IVC diameter [collapsibility (CI-IVC), distensibility (dIVC), and delta (ΔIVC) indices].Results: There were significant differences between the 3 indices (CI-IVC, dIVC, and ΔIVC) according to the pressure groups [(10/5),(10/0), (0/5), (t tube 0/0)]. The median value for the dIVC percentages was ≤18% for all of the positive pressure support hypervolemicgroups, apart from the hypervolemic t tube group (19%). For the hypervolemic groups, the best estimation according to the cut-off valueappeared to be for the dIVC. Values with the highest sensitivity for differentiation of the hypovolemic individuals were calculated withthe dIVC.Conclusion: The dIVC had a more accurate predictive role in predicting the volume status when compared with the CI-IVC and ΔIVC,and may be used reliably with positive pressure supports.