Acute hemodynamic effects of increasing hemoglobin concentration in children with a right to left ventricular shunt and relative anemia.

The short-term effects of increasing hemoglobin concentration were evaluated at cardiac catheterization in seven children (aged 0.3 to 7.5 years) with a right to left ventricular shunt and relative anemia. Diagnoses were tetralogy of Fallot in six and L-transposition of the great vessels with ventricular septal defect and pulmonary stenosis in one. Before and 20 minutes after isovolumic partial exchange transfusion with 20 ml/kg packed red cells, the following variables were measured: hemoglobin, partial pressure of oxygen (PO2), oxygen consumption, oxygen saturation and pressure in the aorta, superior vena cava and right and left atria. After partial exchange transfusion, hemoglobin increased from 13.7 +/- 0.5 to 16.4 +/- 0.4 g/100 ml (p less than 0.001, mean +/- SEM). Aortic PO2 increased from 55.0 +/- 3.5 to 62.0 +/- 4.1 mm Hg (p less than 0.01) and aortic oxygen saturation increased from 84.3 +/- 2.3 to 90.9 +/- 1.3% (p less than 0.002). Effective pulmonary blood flow increased by 17% from 2.72 +/- 0.10 to 3.17 +/- 0.10 liters/min per m2 (p less than 0.01), and right to left shunt decreased by 59% from 1.44 +/- 0.29 to 0.59 +/- 0.10 liters/min per m2 (p less than 0.01). Systemic oxygen transport increased from 658 +/- 48 to 738 +/- 46 ml/min per m2 (p less than 0.002). After partial exchange transfusion, systemic vascular resistance increased from 15.9 +/- 1.1 to 20.0 +/- 1.4 units (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)