Correlation of Ultrasonographic Measurement of Inferior Vena Cava Collapsibility Index with Central Venous Pressure in Diagnosis and Management of Neonatal Shock

Background: Neonatal intensive care unit (NICU)Conventionally, Central Venous Pressure (CVP) monitoring has beenused by intensivists to measure intravascular volume. However, it is an invasive procedure resulting in many complications. Non-invasive ultrasonographic measurement of inferior vena cava collapsibility index (IVC-CI) is a promising alternative. Therefore, this study wasconducted to evaluate the correlation of central venous pressure with IVC-CIand establish the cut off valuesfor IVC-CI to diagnose and manage neonatal shock.Methods: The current research was a prospective longitudinal study.All sick neonates requiring intensive hemodynamic monitoring were enrolled in the study and umbilical vein catheterization was performedto measure CVP. IVC diameters and IVC-CI were measured using ultrasound. Based on CVP, the patients were classified into three categories: hypovolemic (CVP<5 cmH2O), euvolemic (CVP 5-8 cmH2O), and hypervolemic (CVP>8 cmH2O) and managed with intravenous fluid boluses and/or inotropes, accordingly. CVP and IVC-CI were again recorded after the intervention and compared with the previous values.Results: A total of 76(62.3%) males and 46 (37.7%) females were included in the study with a mean age of 27.16±17.5 years. There was a strong negative correlation,which was statistically significant, between CVP and IVC-CI (r= -0.913, n=122, P<0.001). After luid resuscitation in the hypovolemic group, CVP improved from 2.31±0.92 to 5.88±1.79 cmH2O and IVC-CI changed from 62.39±6.005 to 33.02±2.64% which was statistically signi icant(P<0.001). After the administration of inotropes in the hypervolemic group, CVP dropped from 10.86±9.07 to 9.07±1.85cmH2O and IVC-CI changed from 11.27±4.71 to 24.3±13.3% which was again statistically signi icant(P<0.001). The receiver operator characteristic (ROC) curve analysis indicated that the IVC-CI cut-off of 55% predicted CVP <5 cmH2O with 87.9% sensitivity, 82% speci icity, 75.3%positive predictive value and 58.9% negative predictive value. IVC-CI cut-off of 20% predicted CVP >8 cmH2O with 91.1% sensitivity, 83.2% speci icity, 71.8% positive predictive value and 50.6% negative predictive value.Conclusion: The obtained results revealed an inverse correlation between CVP and IVC-CI, and it was concluded that IVC-CI can provide a useful guide in the diagnosis and management of shock in sick newborns.