Hemodynamic assessment in acute settings

Doppler echocardiography is increasingly used as a first-line method for th e hemodynamic assessment of patients with acute circulatory failure. Diagno stic algorithm depends on the clinical setting, medical history and ongoing treatment. Diagnostic accuracy and therapeutic impact are particularly rel evant in the presence of acute circulatory failure which is usually associa ted with typical echocardiographic findings. In cases of increased central venous pressure, obstructive shock due to tamponade or massive pulmonary em bolism, or a right ventricular infarction must be excluded. In cases of inc reased pulmonary venous pressure, severe left ventricular systolic dysfunct ion associated with a restrictive Doppler profile of left ventricular filli ng indicate a cardiogenic shock. In the absence of suggestive clinical find ings, echocardiography should exclude a hypovolemic shock. In the normal he art, hypovolemia is associated with low preload (grossly assessed by the en d-diastolic surface) and low filling pressures (assessed by Doppler). In th e presence of cardiac disease, the evaluation of cardiac preload is not rel iable and a restrictive Doppler profile of ventricular filling precludes fl uid loading. New Doppler echocardiographic techniques, the analysis of hear t-lung interactions in patients on ventilators and sequential examinations after therapeutic interventions appear very useful for identifying mild hyp ovolemia or hypovolemia occurring in patients with cardiac disease. Hyperki netic shock remains a diagnosis of elimination. The increasing use of Doppl er echocardiography for hemodynamic assessment raises the issue of the spec ific training of intensivists responsible for the management of severely il l patients.