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

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. 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. 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. 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.