ABSTRACT
Extracorporeal membrane oxygenation (ECMO) has gained a place as an alternative mode of treatment for newborn infants with life-threatening respiratory failure who do not respond to maximal conventional ventilatory support. To determine any possible changes in cardiac performance during the course of ECMO treatment, we evaluated left and right ventricular output in 10 newborn infants with pulsed Doppler ultrasound before, during, and after ECMO. Birth weight ranged from 2.5 to 4.2 kg and gestational age from 35 to 42 wk. During ECMO, left and right ventricular output decreased proportionally to the amount of bypass flow provided (r = -.82 and -.83, respectively; p less than .001), and were accompanied by a decrease in left ventricular contractility. Pulsed Doppler echocardiography provides a noninvasive method to estimate ventricular outputs during ECMO and to evaluate the response of both ventricles to volume loading during weaning from ECMO.
Subject(s)
Cardiac Output , Extracorporeal Membrane Oxygenation/methods , Respiratory Insufficiency/therapy , Apgar Score , Birth Weight , Echocardiography, Doppler , Gestational Age , Heart Ventricles , Hemodynamics , Humans , Infant, NewbornABSTRACT
Doppler ultrasound was used to study cerebral hemodynamics in the pericallosal artery of 21 newborn infants undergoing extracorporeal membrane oxygenation (ECMO) for intractable respiratory failure. Cerebral blood flow velocity waveforms were obtained pre-ECMO, after every major change in cardiopulmonary bypass flow during ECMO, and post-ECMO. The mean pulsatility index (PI) pre-ECMO was slightly higher than after decannulation, secondary to hypocarbia pre-ECMO. The PI decreased significantly at high (61 to 120 ml/min.kg) cardiopulmonary bypass flows. This was associated with an increase in mean arterial pressure, but not with changes in Hct, PaO2, or PaCO2. A negative curvilinear relationship between the amount of cardiopulmonary bypass flow and PI was found. These data suggest an increase in cerebral blood flow velocity and vasodilation of the cerebral vessels at high cardiopulmonary bypass flows, and may explain the occurrence of intracranial hemorrhage in infants undergoing ECMO.
Subject(s)
Cerebrovascular Circulation , Extracorporeal Membrane Oxygenation , Respiratory Insufficiency/physiopathology , Blood Flow Velocity , Blood Pressure , Carbon Dioxide/blood , Cerebral Hemorrhage/etiology , Extracorporeal Membrane Oxygenation/adverse effects , Humans , Infant, Newborn , Oxygen/blood , Partial Pressure , Respiratory Insufficiency/therapyABSTRACT
Iatrogenic lung perforation during closed tube thoracostomy for pneumothorax in neonates apparently occurs with disturbing frequency. This potentially lethal complication may be minimized by strict adherence to proper technique. In addition, an added margin of safety may be established by allowing some air to remain in the pleural space prior to placement of a chest tube. If iatrogenic perforation of the lung occurs despite appropriate precautions, surgical intervention may be indicated.
