Erythrocythemia as a Cause of Respiratory Distress in the Newborn: Radiologic Findings

Abstract

The frequent occurrence of erythrocythemia and presumed transient hypervolemia (as a result of excessive placental transfusion, maternofetal hemorrhage, twin-to-twin transfusion, or excessive fetal red-blood-cell production) has been the subject of recent reports in the pediatric literature (1, 2). The occurrence in these babies of either neurologic, gastrointestinal, or cardiopulmonary abnormalities has been noted (3). That such infants may present a clinical picture similar to that of idiopathic respiratory distress syndrome has been apparent to pediatricians but less so to radiologists. We have seen several children referred for chest roentgenography with a possible diagnosis of idiopathic respiratory distress syndrome who presented with a typical clinical picture of erythrocythemia as evidenced by high hematocrits. In these infants, the respiratory distress was transient. From a radiological standpoint, at least six infants with cardiomegaly, pulmonary vascular congestion, and a small amount of pleural fluid or subpulmonary edema have been seen. The correlation between these findings and the elevation of the hematocrit has raised the possibility of a causal relationship. The radiologic appearance of the heart and lungs has been sufficiently constant that recently we have been able to suggest the presence of a high hematocrit from the appearance of the chest film. It is the purpose of the present report to describe the clinical and radiological findings in these cases. Case Report A Negro female infant, weighing 8 lb. 5 oz., presented with respiratory distress and plethoric cyanosis shortly after birth. Physical examination was within normal limits except for increased respiratory rate. Evaluation of the heart was within normal limits. A venous hematocrit was 75, and a clinical diagnosis of maternofetal transfusion was entertained. Because of the respiratory distress, the infant was referred for a chest film which revealed cardiomegaly, pulmonary vascular congestion, and a small amount of pleural fluid or subpleural pulmonary edema. The clinical course was uneventful, and the infant recovered over the next two days. At re-examination of the chest at forty-eight hours the findings were within normal limits. Comment: The radiologic and clinical findings in this infant were typical of at least 5 other infants who have come to our attention over the last two years. We suspect that a small amount of pleural fluid is present in these infants but lateral decubitus films have not been taken and none of the infants were tapped or came to autopsy. We cannot, therefore, be certain whether the appearance of the periphery of the lung is due to the presence of pleural fluid or subpleural pulmonary edema or hemorrhage. Discussion As in most infants with respiratory distress in a normal maternity population, it is impossible to be sure of the exact cause of the abnormality. Most of these infants survive, and therefore pathologic correlation is impossible.