兒科學(xué)之小兒貧血

1、Anemia in childhood (小兒貧血)Dept. of pediatrics李圭華,第十五章,Teaching purpose,To understand features of hematopoiesis and blood in children.To comprehend clinical features, diagnosis and therapy of anemia.To understand th

2、e definition, grade division and classification of anemia in children.To master etiology, pathogenosis, diagnosis, therapy and prevention of nutritional iron deficiency anemia and nutritional megaloblastic anemia.,Featu

3、res of hematopoiesis in children,Hematopoiesis in fetal period（胎兒期造血） Developmental hematopoiesis occurs in three anatomic stages—mesoblastic（中胚層）, hepatic（肝）, and myeloid（骨髓）.,,Fig.Hematopoiesis in fetal period,,yolk

4、sac,liver,spleen,Bone marrow,lymph node,Features of hematopoiesis in children,Hematopoiesis after birth Hematopoesis in bone marrow Extramedullary hemopoiesis 　　（骨髓外造血）,Hematopoesis in bone marrow,Yellow bone marr

5、ow（黃骨髓） can come back to red bone marrow（紅骨髓） when hematopoetic need increases . Yellow bone marrow is deficiency in children, especially in infant and toddler period.,When hematopoietic demand increases, liver, spleen a

6、nd lymph nodes come back to the Status to produce blood cells, hepatomegaly（肝腫大） and splenomegaly（脾腫大） appears, and maybe there are immature erythrocytes and granulocytes in circulating blood. Extramedullary hemopoiesis

7、is the specific phenomena only appearing in infant and toddler.,Extramedullary hemopoiesis（髓外造血）,Features of blood in children,Erythrocyte and hemoglobin,,,,,,,,,,,,,,,,76543210,12h,10d,3m,6m,1y,RBC(× 1012/L)

8、,Years,,Hemoglobin,,,At birth,1 yr,2 yr,,,,,,,,,,,,Leucocyte count,WBC×109/L,9h,10d,1y,8y,1,2,3,,,,,,,,,,,%,20,40,60,80,0,5d,5y,Differential count of WBC(白細(xì)胞分類計數(shù)),Lymphocyte淋巴細(xì)胞,Granulocyte粒細(xì)胞,Morphological class

9、ification of anemia,,,,,,Blood routine Hypochromic microcytic Macrocytic Normocytic （Hb↓＞RBC↓） （Hb↓＜RBC↓) （Hb↓ =RBC↓）IDA （缺鐵性貧血） megaloblastic 　 acute bleedingThal

10、assemia 　　　　　Vit B12↓↓ hemolytic anemiasideroblastic anemia folic acid ↓ 　aplastic anemiaChronic infection most of secondary

11、 anemia,,,,,,,The criterion of anemia.,Nutritional iron deficiency anemia (IDA) 營養(yǎng)性缺鐵性貧血,Zhou, male, 10 months old. Paleness in face and lips for 4 mons. His f

12、acial expression became more and more pale since 6 months of age. Without fever and bleeding. He was premature birth at 33 weeks of gestational age and fed with Mother's milk only.,Case 1,PE: Pallor. no jaundice and

13、 hemorrhagic spots in skin and sclera; Bilateral submandibular lymph nodes are 0.8×0.8cm. Breath sounds in lungs are distinct; there are no rhonchi and moist rale. HR 100/min.There is II/VI systolic murmur in preco

14、rdial region. The liver and spleen enlarge to 4 cm and 3 cm below lower costa margin respectively.,Case 1,Blood routine test,,,questions,Do an anemia exist? Which kind of anemia does it belong?,answer,Hypochromic　microcy

15、tic anemia(小細(xì)胞低色素性貧血）,questions,What is the cause of anemia in the case above?,answer,The cause of anemia in the case above is deficiency of iron because he is premature and is fed with Mother's milk only.,etiology,

16、The etiological factors of nutritional iron deficiency anemia: Stored iron deficiency at birth. Inadequate diet. Rapidly growth. Malabsorption. Excessive loss of iron.,questions,Next examinations?,Smear of Blood,no

17、rmal,The patient’,Bone marrow,Bone marrow examination,The bone marrow is hypercellular, with erythroid hyperplasia（過度增生）. The normoblasts(幼紅細(xì)胞) may have scanty, fragmented cytoplasm with poor hemoglobinization. Leukocyte

18、s and megakaryocytes are normal. Hemosidenin cannot be demonstrated in marrow specimens by Prussian blue staining.,questions,How do iron deficiency cause anemia?,questions,Pathogenesis of nutritional iron deficiency anem

19、ia .,鐵缺乏　 貯存鐵　 血清鐵 血紅蛋白鐵↓ 酶鐵↓ 紅細(xì)胞內(nèi)Ｈｂ合成↓↓ 含鐵酶↓ 細(xì)胞分裂不受影響 　 　 鐵依賴酶↓　　　　　 Ｈｂ↓↓，RBC正?；颉?某些細(xì)胞功能紊亂，如 　　　 生物氧化、細(xì)胞呼吸小細(xì)胞低色素性貧血 　　 神經(jīng)

20、遞質(zhì)分解與合成等 　 　　　　　　　 　血液系統(tǒng)癥狀 　　　 非血液系統(tǒng)癥狀 一般貧血表現(xiàn) 　　　　 行為發(fā)育異常 髓外造血表現(xiàn) 　　 皮膚粘膜損害 心血管系統(tǒng)癥狀 細(xì)胞免疫功能↓缺鐵性貧血發(fā)病機(jī)理,,,,,,,,,,,,,,Iron study,,Therapy,good nu

21、rsingremoval of etiological factors treatment with iron preparation,,Oral administration of simple ferrous salts 　ferrous sulfate　ferrous gluconate　ferrors fumarate　polysaccharide iron Dosage: 4-6mg/kg elemental i

22、ron per day,Oral iron preparation,,Administration the iron prior to meals Administration ascorbic acid with iron preparation. Therapeutic course: withdrawal of iron preparation 6-8 weeks after hemoglobin recover to nor

23、mal level or when SF and FEP is normal.,Oral iron preparation,,Parenteral iron To be administered only for gastrointestinal malabsorption or severe intolerance prevents effective oral iron therapy.,Reticulocytosis,,Tra

24、nsfusion,Prevention,Nutritional Megaloblastic Anemia（營養(yǎng)性巨幼細(xì)胞性貧血）,Folic acid and vitamin B12 deficiency are primary causes of megaloblastic anemia.,Case 2.,Zhou, male, 8 month old.　pallor for 2 mo . progressive drowsines

25、s and go asleep for 20 hr pre day. He can not smile and to raise his head, which can be done before. He was fed with Mother's milk only.,Case 2.,PE: emotional expression Sluggishness（呆滯）, Pallor. no jaundice, rashes

26、and hemorrhagic spots in skin; pallor in his lips. Breath sounds are distinct and there are no rale in lungs. Heart rate is 110 times per minute. The liver and spleen enlarge to 3 centimeters and 4 centimeters below lowe

27、r costa margin respectively.,Blood routine,,,,questions:,1.Which kind of anemia it belongs?,Answer,The clinic data shows a macrocytic anemia.,Smear of blood,patient,normal,Smear of patient’blood,BM(骨髓),Bone marrow examin

28、ation,The bone marrow is hypercellular because of erythroid hyperplasia. Megaloblastic changes are prominent, although some normal RBC precursors may also be found. Large, abnormal neutrophilic forms (giant metamyelocyte

29、s) with cytoplasmic vacuolation are seen, as well as hypersegmentation of the nuclei of megakaryocytes.,questions:,2. Is it caused by deficiency of folic acid or vitamin B12 ?,Answer,In this case, macrocytic anemia is ca

30、used by deficiency of vitamin B12.,Why?,questions:,3.what is the differences in clinical manifestation between deficiency of folic acid and deficiency of vitamin B12?,,葉酸↓ 四氫葉酸↓ 核苷酸尤其胸苷合成↓　

31、 VitB12↓ DNA合成↓ RNA合成正常 神經(jīng)髓鞘中脂 細(xì)胞分裂↓ 蛋白質(zhì),如Hb 蛋白合成不足 細(xì)胞增殖↓ 合成正常 神經(jīng)纖維功能 細(xì)胞巨幼變 不完整

32、 細(xì)胞數(shù)量下降 　　 表情呆滯,反應(yīng)差 RBC↓ WBC↓ PLT↓ 其它組織 發(fā)育落后,常倒退　　　　　　　 　　 細(xì)胞↓　 肢體震顫　　　　　　　　　　　　　　　　　　 可有病理反射 精神神經(jīng)癥狀 巨幼細(xì)胞性貧血,,,,,,,,,,,,,營養(yǎng)性巨幼細(xì)胞性貧血發(fā)病機(jī)理,

33、,,Answer,In the macroblastic anemia produced by deficiency of vitamin B12, the symptoms and signs include those of anemia and neuropathy. Patients develop a demyelinating lesion of neurons of the spinal column and cerebr

34、al cortex. This condition results in paresthesias(感覺異常) of the hands and feet, unsteadiness of gait, and eventually memory loss and personality（智力） changes. There is retard of intellective and physical development. Tremb

35、ling（震顫） of Extremities or head, hypertension of muscle, tendon reflex reinforcement, positive Babinski's sign may appear.,Diagnosis,Preliminary assessment of megaloblastic anemia,Diagnosis,Final diagnosis: To

36、distinguish the deficiency of folic acid with the deficiency of vitamin B12.,Marked symptoms and signs of central nervous system.( it supports defiency of vitamin B12.)Measurement of serum folate level and cobalamin lev

37、el.,Final diagnosis,Diagnosis,Therapy,To remove the etiological factors and ameliorate diet.,Special treatment:Vitamin B12 preparation to treat vitamin B12 deficiency. Not to use folic acid preparation in patients with

38、vitamin B12 deficiency only. Folic acid preparation to treat folic acid deficiency.,Treatment,Therapy,循征醫(yī)學(xué)思考題,什么是髓外造血？小兒紅細(xì)胞和血紅蛋白有何變化規(guī)律？什么是生理性貧血？各年齡組貧血的診斷標(biāo)準(zhǔn)是什么？小兒白細(xì)胞計數(shù)有何變化規(guī)律？白細(xì)胞計數(shù)兩次交叉的時間是什么？按形態(tài)學(xué)分類貧血分那幾類？兒科小細(xì)胞低色素性和大細(xì)胞

39、性貧血常見于那些疾??？那些病因可引起機(jī)體缺鐵？最常見的病因是什么？,人體缺鐵如何引起貧血及非造血系統(tǒng)系統(tǒng)癥狀？檢查機(jī)體缺鐵的較靈敏的化驗指標(biāo)有哪些？這些指標(biāo)反映是鐵缺乏的哪一階段？補鐵首選那種劑型？注射鐵劑是否比口服鐵劑好？補充鐵劑的療程應(yīng)多長？是否血常規(guī)恢復(fù)正常后即可停藥？判斷鐵劑治療有效的簡便，靈敏指標(biāo)是什么？缺鐵性貧血病人什么情況下考慮輸血？是成份輸血還是輸全血？是否貧血越嚴(yán)重輸血應(yīng)越快，越多，為什么？,那些原因可致維