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