RESUMO
This study was designed to compare the effectiveness of laboratory tests for iron deficiency (mean corpuscular volume, erythrocyte protoporphyrin, transferrin saturation, and serum ferritin) in predicting hemoglobin response to iron therapy in infants found to have low Hgb concentrations. Screening for anemia was performed on capillary blood of 1,128 healthy 1-year-old infants of United States Air Force personnel. The 25% who had Hgb values less than 11.5 gm/dl were asked to return for tests on venous blood before therapy and again after three months of therapy. Of the 188 infants completing therapy, 66 (35%) had a rise in Hgb concentration greater than or equal to 1.0 gm/dl and were designated responders. None of the confirmatory tests on venous blood reliably distinguished responders from those who subsequently showed no response. By using any one of the tests in combination with a capillary Hgb value less than 11.5 gm/dl, more than half of the infants with an abnormal value responded. But well over half of the responders would have been missed if treatment had been restricted to infants with abnormal values. Neither changes in the criteria for normality nor combinations of tests substantially improved our ability to distinguish the two groups. Because of the difficulty in distinguishing responders from nonresponders with additional laboratory tests and because of the simplicity, low cost, and relative safety of iron therapy in infants, we favor an initial therapeutic trial of iron first for determining the cause of low Hgb values in similar high-risk populations. Further costly workup can then be reserved for the small number of infants who still have unexplained Hgb concentrations less than 11.0 gm/dl after a therapeutic trial.
Assuntos
Anemia Hipocrômica/sangue , Ferro/uso terapêutico , Anemia Hipocrômica/tratamento farmacológico , Índices de Eritrócitos , Ferritinas/sangue , Compostos Ferrosos/uso terapêutico , Hemoglobinas/análise , Humanos , Lactente , Protoporfirinas/sangue , Transferrina/sangueRESUMO
Initial screening for anemia was performed on a capillary blood sample in 800 apparently healthy one-year-old white infants. Twenty-six percent had a Hgb or MCV below the estimated tenth percentile of normal and were asked to return for blood counts on a venous sample. They were then started on a three-month course of oral iron. Of the 151 infants who satisfactorily completed the treatment regimen, 54 had a greater than or equal to 1 gm/dl rise in venous Hgb (2.8 infants treated/response). If conformation of the capillary by the venous values had been a prerequisite for treatment, the size of the treatment group would have decreased from 151 to 87, the response rate would have been improved to 2.0 infants treated per response, but 11 of the infants who had a greater than or equal to 1 gm/dl response would have been missed. Since toxicity from iron therapy is rare, either the use of capillary blood counts alone or in combination with venous values constitutes a satisfactory basis for a therapeutic trial of iron in similar populations. Further evaluation can then be reserved for the small number whose Hgb remains below the lower limit of normal after treatment.
Assuntos
Anemia Hipocrômica/diagnóstico , Hemoglobinas/análise , Ferro/uso terapêutico , Anemia Hipocrômica/dietoterapia , Humanos , Lactente , Programas de RastreamentoRESUMO
The purpose of this study was to determine the Hgb response to a therapeutic trial of iron in infants with anemia compared to those with low-normal hemoglobin values. Hgb was determined in 1.128 one-year-old infants. The 278 infants (25%) who had an Hgb less than 11.5 gm/dl were given a three-month oral course of ferrous sulfate (3 mg iron/kg/day); the regimen was satisfactorily completed by 188 infants. Of the 75 infants whose initial capillary Hgb was in the anemic range (Hgb less than 11.0 gm/dl), 45% had an increase in venous Hgb greater than or equal to 1.0 gm/dl. Of the 113 infants with initial capillary values in the low-normal range (11.0 to 11.4 gm/dl), 28% had greater than or equal to 1.0 gm/dl Hgb response. Despite the lower rate of response in the low-normal group, almost half of the infants with a greater than or equal to 1 gm/dl response would have been missed by using the generally accepted cutoff value of 11 gm/dl for a therapeutic trial. Because of the low cost and simplicity of a therapeutic trial, we favor including the low-normal Hgb group for a therapeutic trial of iron in order to avoid missing iron-responsive individuals among groups of infants with a similarly high prevalence of iron deficiency anemia.