Correlation between Inferior Vena Cava Diameter and Central Venous Pressure in Critically Ill Patients
Weerapan Wiwatworapan MD*, Nuchapa Ratanajaratroj MD*, Buncha Sookananchai MD*
Affiliation : * Department of Medicine, Maharat Nakhon Ratchasima Hospital, Nakhon Ratchasima, Thailand
Background : The inferior vena cava (IVC) diameter is often used to estimate central venous pressure (CVP); however, the
correlation and the cutoff of IVC compared with CVP have not yet been described in a Thai-population.
Material and Method: A cross-sectional study evaluated the critically ill patients in the medical intensive care unit who had
a central venous catheter inserted. The correlation between CVP and IVC diameter measured by a 2-dimensional, long-axis
subxiphoid view at the end-expiratory phase with bedside ultrasonography were evaluated.
Results : Forty-seven patients with a mean age of 60 + 16 years (range, 18 to 91) were studied. Correlation (r) between end-
expiration IVC diameter and CVP was 0.75 (95% CI 0.59-0.85; p < 0.0001). An IVC diameter of < 10 mm predicted CVP
of 10 cmH2O (sensitivity 77% and specificity 91%) and IVC diameter of > 15 mm predicted CVP of 15 cmH2O (sensitivity
90% and specificity 89%).
Conclusion : The present study indicate that the measurement of the IVC diameter has a good correlation with CVP in Thai-
population and useful for assessment of the volume status. The measurement of the IVC by ultrasonography may be an
important additional evaluation of critically ill patients.
Keywords : Inferior vena cava, Central venous pressure, Ultrasonography
