VALUE OF DOPPLER ULTRASONOGRAPHY IN NEONATAL AND PEDIATRIC INTENSIVE-CARE

In neonatal or pediatric intensive care patients, Doppler echocardiography is an extremly valuable tool that provides information on heart structure and function, aortic and pulmonary blood flows, and even pressures under specific conditions. Doppler echocardiography is especially useful in severe neonatal hypoxemia, patent ductus arteriosus, and shock. 1) In hypoxic neonates, evaluation of ductus arteriosus and atrial shunting and of pulmonary blood flows establishes whether hypoxia is due to intrapulmonary and/or extrapulmonary shunting and whether extrapulmonary shunting is the result of high pulmonary resistance, abnormal compliance of the right or left ventricle, or left ventricular dysfunction. 2) In patients with worsening respiratory distress, the contribution of a left-to-right shunt through a patent ductus arteriosus can be suspected clinically and evaluated by Doppler echocardiography. 3) In patients with a clinical suspicion of shock based on physical and roentgenographic findings, Doppler echocardiography provides additional information, allowing to confirm a clinically suspected diagnosis of low output syndrome in patients with normal blood pressure or to differentiate cardiovascular collapse with normal blood pressure or to differentiate cardiovascular collapse with normal, increased or decreased left ventricular output in patients with arterial hypotension. The limitations of noninvasive hemodynamic evaluation are discussed. These limitations can be overcome by scrupulously adhering to technical rules and by comparing Doppler echocardiography findings with those of M-mode and B-mode echocardiography, physical examination and chest films. Under these conditions, the information provided by Doppler echocardiography is usually adequate for selecting the most appropriate management strategy in patients with cardiovascular failure.