ABSTRACT
Partial liquid ventilation using conventional ventilatory schemes improves lung function in animal models of respiratory failure. We examined the feasibility of high-frequency partial liquid ventilation in the preterm lamb with respiratory distress syndrome and evaluated its effect on pulmonary and systemic hemodynamics. Seventeen lambs were studied in three groups: high-frequency gas ventilation (Gas group), high-frequency partial liquid ventilation (Liquid group), and high-frequency partial liquid ventilation with hypoxia-hypercarbia (Liquid-Hypoxia group). High-frequency partial liquid ventilation increased oxygenation compared with high-frequency gas ventilation over 5 h (arterial oxygen tension 253 +/- 21.3 vs. 17 +/- 1.8 Torr; P < 0.001). Pulmonary vascular resistance decreased 78% (P < 0.001), pulmonary blood flow increased fivefold (P < 0.001), and aortic pressure was maintained (P < 0.01) in the Liquid group, in contrast to progressive hypoxemia, hypercarbia, and shock in the Gas group. Central venous pressure did not change. The Liquid-Hypoxia group was similar to the Gas group. We conclude that high-frequency partial liquid ventilation improves gas exchange and stabilizes pulmonary and systemic hemodynamics compared with high-frequency gas ventilation. The stabilization appears to be due in large part to improvement in gas exchange.
Subject(s)
Hemodynamics/physiology , High-Frequency Ventilation , Pulmonary Gas Exchange/physiology , Respiratory Distress Syndrome, Newborn/physiopathology , Animals , Animals, Newborn , Gestational Age , High-Frequency Jet Ventilation , Humans , Infant, Newborn , Lung/pathology , Lung/physiopathology , Oxygen/blood , Pulmonary Circulation/physiology , Respiratory Distress Syndrome, Newborn/pathology , Sheep , Vascular Resistance/physiologyABSTRACT
Total anomalous pulmonary venous return (TAPVR) is an uncommon cause of cyanotic congenital heart disease in the neonatal period. This diagnosis is often made by echocardiography. We present two cases where echocardiography was not confirmatory. Computerized tomography (CT) scan of the chest and abdomen with contrast was performed instead of cardiac catheterization to establish the diagnosis. We suggest that CT with contrast is a noninvasive modality to obtain anatomic details of pulmonary venous drainage in TAPVR when echocardiography is inconclusive.