[Non-invasive evaluation of central venous pressure derived from respiratory variations in the diameter of the inferior vena cava].

To evaluate non invasive means of estimating central venous pressure, the respiratory motion of the inferior vena cava (IVC) was analysed by echocardiography in 65 patients. The caval index was measured in subcostal views within 2 cm of the right atrium origin of IVC. Parameters were correlated with simultaneous measured central venous pressure (CVP) by catheter positioned in the internal jugular vein. Patients were classified in 3 groups: A) 45 patients with caval index > or = 20% and normal CVP; B) 6 patients with caval index > 20% and elevated value of CVP; C) 14 patients with caval index < 20% elevated value of CVP. Group A and B had no sign of cardiac failure, on reverse group C. Caval index was inversely related to mean CVP. A caval index > or = 20% indicate normal CVP, a caval index < 20% is related to an elevated value of CVP. This method appears to be useful for noninvasive estimation of mean CVP.