VALUE OF DOPPLER ULTRASONOGRAPHY IN NEONA TAL AND PEDIATRIC INTENSIVE-CARE

In neonatal or pediatric intensive care patients, Doppler echocardiogr aphy is an extremly valuable tool that provides information on heart s tructure and function, aortic and pulmonary blood flows, and even pres sures under specific conditions. Doppler echocardiography is especiall y useful in severe neonatal hypoxemia, patent ductus arteriosus, and s hock. 1) In hypoxic neonates, evaluation of ductus arteriosus and atri al shunting and of pulmonary blood flows establishes whether hypoxia i s due to intrapulmonary and/or extrapulmonary shunting and whether ext rapulmonary shunting is the result of high pulmonary resistance, abnor mal compliance of the right or left ventricle, or left ventricular dys function. 2) In patients with worsening respiratory distress, the cont ribution of a left-to-right shunt through a patent ductus arteriosus c an be suspected clinically and evaluated by Doppler echocardiography. 3) In patients with a clinical suspicion of shock based on physical an d roentgenographic findings, Doppler echocardiography provides additio nal information, allowing to confirm a clinically suspected diagnosis of low output syndrome in patients with normal blood pressure or to di fferentiate cardiovascular collapse with normal blood pressure or to d ifferentiate cardiovascular collapse with normal, increased or decreas ed 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 rul es 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 echocard iography is usually adequate for selecting the most appropriate manage ment strategy in patients with cardiovascular failure.