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Does inferior vena cava size predict right atrial pressures in patients receiving mechanical ventilation?

The inferior vena cava diameter and its respiratory response are used to estimate right atrial pressures in spontaneously breathing patients but its value in patients receiving mechanical ventilation is unvalidated. Forty-nine patients undergoing mechanical ventilation were prospectively evaluated in the intensive or coronary care units with two-dimensional echocardiography of the inferior vena cava and simultaneous measurements of mean right atrial pressures by central venous or pulmonary artery catheter. Correlation between inferior vena cava diameter at expiration and mean right atrial pressure was only 0.58. The correlation between inspiratory change in inferior vena cava diameter and mean right atrial pressure was poor (r = 0.13). Despite these correlations, an inferior vena cava diameter of < or = 12 mm predicted a right atrial pressure of 10 mm Hg or less 100% of the time, but sensitivity was only 25%. An inferior vena cava diameter > 12 mm had no predictive value for right atrial pressure.

Adolescent↗

PubMedDate not supplied

Canadian consensus recommendations for the measurement and reporting of diastolic dysfunction by echocardiography: from the Investigators of Consensus on Diastolic Dysfunction by Echocardiography.

Abnormalities of diastolic filling are increasingly recognized as a cause of symptoms and predictors of outcome in patients with most forms of heart disease. Noninvasive assessment of diastolic filling is possible in almost all patients, but accurate evaluation must relate echocardiographic Doppler measurements to the complex physiologic and hemodynamic factors responsible for normal and abnormal filling. This evaluation has been facilitated by recent correlation of Doppler measurement of mitral and pulmonary venous inflow with hemodynamic studies. These studies have confirmed that when a careful, integrated approach is taken, Doppler flow patterns can document a progressive pattern of abnormality in many conditions. Impaired left ventricular (LV) relaxation is seen early and is recognized by a decrease in early transmitral LV filling and an increased proportion of filling during atrial contraction. As abnormalities progress, increasing LV chamber stiffness and elevated left atrial pressure lead to a "pseudonormal" filling pattern that previously has caused considerable confusion. This can be unmasked by careful evaluation of pulmonary venous inflow and the use of the Valsalva maneuver. When marked diastolic abnormalities are present, LV filling has restrictive features characterized by rapid early filling, a very stiff left ventricle with high filling pressures, and a poor prognosis. Routine measurement of indexes of diastolic filling have been hampered by uncertainty as to what should be measured, what techniques should be used, definition of normal values, and a clear method of reporting findings. This report represents the efforts of a Canadian consensus group to define a national standard for the performance and reporting of echocardiographic Doppler studies of diastolic filling.

Aged↗