Background and objective: Central venous pressure, intrathoracic blood volume, and left ventricular end-diastolic area are reliable measures of cardiac preload under stable clinical conditions. The purpose of this study was to compare different preload parameters over 24 h under conditions of multiple, frequently changing treatments in early septic shock.
Methods: In 28 mechanically ventilated patients within 6 h of the onset of septic shock, left ventricular end-diastolic area was measured using transoesophageal echocardiography. Intrathoracic blood volume, stroke volume variation, and central venous pressure were analysed as preload parameters. The relation between parameter changes and changes in therapy was examined with respect to cardiac index and stroke volume index.
Results: Regarding preload variables, linear regression analyses revealed a significant correlation between left ventricular end-diastolic area and stroke volume index (r2 = 0.59, P < 0.001) and cardiac index (r2 = 0.41, P < 0.001), respectively. Changes in left ventricular end-diastolic index and intrathoracic blood volume index reflected changes in the stroke volume index, whereas central venous pressure did not. Myocardial responsiveness also failed to predict changes in the stroke volume index.
Conclusion: Only the left ventricular end-diastolic area index may help predict preload in ventilated patients with early septic shock.