Echocardiographic Inferior Vena Cava Measurement As An Alternative to Central Venous Pressure Measurement in Neonates

To evaluate the correlation between echocardiographic inferior vena cava (IVC) measurements and central venous pressure (CVP) in neonates. Also, to evaluate the correlation between IVC measurements and gestational age (GA) and body weight (BW).

This cross sectional analytical study was conducted from June 2014 through June 2016 in a level III NICU. All neonates requiring intensive hemodynamic monitoring and having umbilical venous catheter (UVC) in place for clinical indications were enrolled in the study. IVC measurements were recorded by echocardiography (ECHO) and CVP was measured concomitantly in neonates having appropriate sized UVC in place. IVC measurements were evaluated and compared for any correlation with the CVP, GA and BW.

Fifty neonates with median gestation of 37 wk [Q1 = 29.2, Q3 = 37.8, interquartile range (IQR) = 8.6 wk] and median birth weight of 2420 g (Q1 = 923.5, Q3 = 2850, IQR = 1926.5 g) were included in the study. A strong negative linear correlation was observed between IVC collapsibility index (IVC-CI) and CVP (r = -0.968, r² = -0.937, p 0.000). No correlation was observed between IVC-CI and GA or BW. IVC minimum and IVC maximum diameters did not correlate with CVP but correlated well with GA and BW.

Echocardiographic IVC-CI measurement has a good correlation with CVP measurement in neonates. The clinical use will depend on the ability of IVC-CI to predict surrogate markers of tissue perfusion in shock.