Cardiovascular function in children with severe anemia

We investigated the hemodynamic status of seven children (aged 7 months to 14 years) with severe iron-deficiency anemia or anemia due to renal disease before and after the anemias were corrected by isovolumetric exchange transfusions. In the anemic state (Hb 1.9 to 3.8 g/100 ml) mean values for cardiac index were 7.71 L/min/m 2 , for heart rates 129/min, for stroke index 61.7 ml/m 2 , for diastolic pressure 61 mm Hg, and for systemic vascular resistances 11.5 resistance units (RU). After the anemias were corrected, mean values for cardiac index fell to 4.58 L/min/m 2 , heart rate to 92/min, and stroke index to 50.5 ml/m 2 ; diastolic pressure rose to 74 mm Hg, and systemic vascular resistance to 22.8 RU. Post-exchange values were statistically significantly different from anemic values and were within normal limits for children. The mean cardiac index in anemic children was approximately the same as in adults with equally severe anemia; in children, increases in heart rate were greater and increases in stroke volume less than in equally anemic adults. Heart size (estimated by cardiothoracic ratio in eight anemic children) was increased. After the exchange transfusions it decreased from a mean of 55.4% to 51.2% ( P