The Correlation Between Inferior Vena Cava Diameter Measured by Ultrasonography and Central Venous Pressure.

OBJECTIVE: To find a correlation between inferior vena cava (IVC) diameters, IVC compressibility index (CI) and central venous pressure (CVP).

METHODS: Prospective observational study was done at pediatric intensive care unit (PICU) of Kalawati Saran Children's Hospital (KSCH). Fifty children aged 5-18 y, presenting with shock were enrolled for the study. IVC diameters, CI and relevant clinical data were noted at enrollment, 30 min, 1 h, 6 h, and 12 h. Central line was placed at the time of admission.

RESULTS: Of 50 children enrolled, 28 were boys, with a mean age of 11 y. More than 80% of cases were diagnosed as septic shock. Mean maximum and minimum IVC diameter of 8.3 ± 2 mm and 3.7 ± 1.7 mm, respectively CI 58.2 ± 7% and CVP of 5.4 ± 1.5 cm of H2 O was observed at admission. CVP and IVC diameters showed a serial improvement with treatment; CI showed a serial decrease with treatment. Heart rate (HR) and systolic blood pressure (SBP) also showed a serial improvement at 12 h (p < 0.05). CVP showed a positive correlation with IVC diameter (r +0.312; p < 0.05), and a negative correlation with CI (r -0.343; p < 0.05).

CONCLUSIONS: Effective fluid resuscitation improves IVC diameters with a decrease in CI. IVC diameter has a positive correlation to CVP and CI has a negative correlation to CVP.