留学生缺铁.ppt

1、Iron Deficiency Anemia,IDA,This is the most common cause of anemia in childhood. It usually results from inadequate dietary intake rather than loss of iron through hemorrhage,Introduction,Diagnosis points common 6-24m Pallor and fatigue Poor dietary intake of iron Chronic blood loss Microcytic, hypo

2、chromic anemia response to the administration of iron,Iron homeostasis,1.Source 2.Distribution and storage 3.Absorption 4.excretion,Iron requirements,The fetus absorbs iron from the mother across the placenta Term infants have adequate reserves for the first 4 months of life Preterm infants have lim

3、ited iron stores and because of their higher rate of growth, they outstrip their reserves by 8 weeks of age,1.Source of iron,Food: sea tangle, edible tree fungus, mushroom, liver, meat, beans and blood products Destructive red blood cells -80% recycle - 20% storage,Both breast milk and cows milk are

4、 low in iron concentration Most formula milk X10, but only 4% is absorbed Dietary sources of iron include red meat, fortified breakfast cereals,dark green vegetables and bread,10-15% absorbed Enhanced by ascorbic acid (vitamineC) Reduced by tannin in tea,2.Iron distribution,Hemoglobin:60-70% Ferriti

5、n and hemosiderin:30% myoglobin: 3% iron enzymes and combined with transferrin: thimbleful,3.Iron storage,2/3 of storage of iron in macrophages (spleen, bone marrow) 1/3 in Kupffer cell of liver In two ways of ferritin and hemosiderin,Regulation of iron absorption,Iron salts are absorbed into entero

6、cytes by the divalent metal transporter (DMT1) Iron is either stored in ferritin complexes or transported into portal circulation by ferroportin after several days, stored iron is lost when enterocyte sloughs off into lumen Fe deficiency increased DMT1 leads to increased absorption Fe overload- decr

7、eased ferroportin leads to increased storage in enterocytes,Iron transport,Food Ferrous iron(Fe+ ) Ferric (Fe+) Apoferritin Transferrin Storage,Iron loss,Excretion -bile -urine -sweat -mucous membrane cells (slough off),Stages of Iron Deficiency,ID: Iron Deficiency (Pre-latent) - ferritin is sensiti

8、ve IDE: Iron Deficiency of Erythropoiesis (latent) - FEP (free erythrocyte protoporphyrin) IDA: Iron Deficiency of Anemia (Frank iron deficiency) - microcytic hypochromic anemia,Stages of iron deficiency,ID: low ferritin, normal serum Fe IDE: low serum Fe, increased TIBC, variable Hb concentrations

9、IDA: microcytic, hypochromic anemia and other systemic symptoms,Microcytic anemia,Quantitative defect in hemoglobin production or globin synthesis DD(differential diagnosis) -iron deficiency -lead poisoning -thalassemia -sideroblastic anemia,1.Poor iron intake,Preterm infants require iron supplement

10、s from 6-8 weeks Term infants will develop iron deficiency after 4 months if Non-fortified formula Early cows milk Breast-feeding beyond 6-months without iron supplements Poor diet associated with low social-economic Strict vegetarians,2.Insufficient iron stores,Premature Twins Severe anemia in moth

11、er,3.Rapid growth,3-5m: 2 times of the weight at birth 1y: 3 times of the weight at birth Premature grows faster Pubertal growth spurt, poor diet menarche,General manifestation,Irritable, lethargy,fatigue, anorexia, palpitations, light-headed, tinnitus Pallor of the skin and mucous membranesmay be t

12、he only sign ( Lip, buccal mucosa, finger bed, conjunctiva),Lab exam,CBC -microcytic/hypochromic anemia -Hb RBC -anisocytosis,The red blood cells here are normal. They have a zone of central pallor about 1/3 the size of the RBC. The RBCs demonstrate minimal variation in size and shape . A few small

13、fuzzy blue platelets are seen. In the center of the field are a band neutrophil on the left and a segmented neutrophil on the right.,The nucleated RBC in the center contains basophilic stippling of the cytoplasm. This suggests a toxic injury to the bone marrow, such as with lead poisoning.,The most

14、common cause for a hypochromic microcytic anemia is iron deficiency.,Lab exam,2. BM -erythroid hyperplasia -absence of iron -the myeloid and megakaryocytes are normal,Lab exam,3. Biochemistry -serum iron -serum ferritin -free erythrocyte protoporphyrin -the total iron-binding capacity,Diagnosis,Diag

15、nosis is confirmed by the blood count and film, supplemented by investigations of iron status. If dietary deficiency is likely, the latter can be omitted and diagnosis confirmed by a positive response to a therapeutic trial of iron.,Diagnosis standard in China,1. Microcytic hypochromic anemia 2. Con

16、vincing evidence of iron deficiency and clinical features 3. SI 62.7umol/L 4. Transferrin satuation 0.15 5. Stainable BM granules disappear, sideroblast15%,Diagnosis standard in China,6.FEP(free erythocyte protoporphyrin in red blood cell)0.9umol/L 7.SF26.5umol 9.Response to the preparation of iron 1+every two of 2-9,Prevention,Assistant food: breast feeding until 5-6m,beyond 6m add Fe supplementation Fe-fortified formula for first 12m Fe-fortified cereal early with solid food Cooking with an iron-pot Avoid cows milk until 9-12m Prevention of