Myocardial, erythropoietic, and metabolic adaptations to anemia of prematurity.
We determined the effects of anemia of prematurity on myocardial, metabolic, and erythropoietic functions. Twelve anemic (hemoglobin range, 65 to 78 gm/L) infants without symptoms (gestational age, (mean +/- SD) 28 +/- 2 weeks; birth weight, 1178 +/- 326 gm) were studied at a postconceptional age of 35 +/- 1.6 weeks. All measurements were done before and 36 to 48 hours after a transfusion of packed erythrocytes. Cardiac output, heart rate, and myocardial function were assessed. Oxygen consumption, carbon dioxide production, resting energy expenditure, arterial oxygen pressure for 50% hemoglobin saturation, and the concentrations of erythropoietin and 2,3-diphosphoglycerate were also determined. After transfusion, increased hemoglobin level (75 +/- 4 to 150 +/- 16 gm/L) and decreased oxyhemoglobin affinity (20.8 +/- 1.7 to 23.6 +/- 2.1 gm/L; p < 0.05) caused a decrease in plasma erythropoietin concentration (from 21.1 +/- 6.2 to 5.8 +/- 1.5 mU/ml; p < 0.01). There was a decrease in heart rate (from 155 +/- 10 beats/min to 146 +/- 7 beats/min) and cardiac output (from 281 +/- 73 ml/kg per minute to 199 +/- 62 ml/kg per minute; p < 0.05). Myocardial function indexes, weight gain, and metabolic demands were normal before and after transfusion. These results suggest that oxygenation is adequately maintained in symptom-free infants with anemia of prematurity.
Lachance
C
C
Department of Neonatology, Hôpital Ste-Justine, University of Montreal, Canada.
Chessex
P
P
Fouron
J C
JC
Widness
J A
JA
Bard
H
H
D000751:Anemia, Neonatal / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D004734:Energy Metabolism; D017707:Erythrocyte Transfusion; D004921:Erythropoietin / Q000097:blood; D006321:Heart / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D010100:Oxygen / Q000378:metabolism
D004921:Erythropoietin; D010100:Oxygen