外文讲义5
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外文讲义5

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外文讲义5 外文讲义5 Presentation Transcript

  • Nutritional iron deficiency anemia
  • Iron Deficiency a Global Problem
      • 58 % of pregnant women in developing countries are anaemic
    31% of children under 5 in developing countries are also anaemic
  • As iron deficiency chiefly influences the synthesis of heme, the production of Hb is decreased, and the red cells become microcyte and hypochromic. this anemia is also named nutritional microcytic anemia. Definition
  • The Hemoglobin Molecule α β
    • Protoporphyrin + iron heme
    • +
    • globin
    • IDA hemeglobin
    Mechanism
  • Iron source Dietary iron is important source, such as meat, fish, liver, yolk, bean… Recycled From the breakdown of red cells, 80 % iron is reutilized to produce Hb Iron metabolism
  • Iron cycle Fe Fe Fe Fe Fe Ferritin Hemosiderin slow Fe Fe Fe Fe Fe Fe Fe Fe Fe Ferritin Ferritin Transferrin Receptor RBC PRECURSOR CIRCULATING RBCs Fe Fe TRANSFERRIN MONONUCLEAR PHAGOCYTES
    •  
    • The iron content :
    • young adult male is about 50mg/kg
    • female average 35mg/kg
    • newborn about 60-90mg/kg
    • 2/3 functional - being used
      • 1/3 stored
    Iron metabolism
    • Iron distribution
    • 65-70% of total body iron content is
    • used to the composition of Hb
    • Smaller amounts of iron are found in
    • myoglobin , enzymes
    Iron metabolism
  • Storage (30%) two forms ferritin hemosiderin which are located primarily in the liver, spleen and bone marrow
      • Hemosiderin is an insoluble iron aggregate derived from ferritin
    Iron metabolism
  • Storage of iron
    • Tissues with higher requirement for iron
    • ( bone marrow, liver) contain more transferrin receptors.
    • Once in tissues, iron is stored as ferritin & hemosiderin compounds, which are present in the liver & bone marrow.
    • The amount of iron in the storage compartment depends on iron balance (positive or negative).
    • Ferritin level reflects amount of stored iron in the body & is important in assessing ID.
  • Plasma Fe 16% 65% 4% 15%
  • two forms of dietary iron: heme meat, fish, and poultry nonheme Flours, cereals, and grain Iron absorption Iron metabolism
  • Iron
    • Heme iron is part of hemoglobin and myoglobin
    • and is obtained from meat of all types.
      • About 20%-25% absorbed
    • Non-heme iron is found in leafy green vegetables,
    • legumes, and meat, and is absorbed at
    • about half (or less) the rate of heme iron.
    • Non-heme iron can also leach out of iron
    • cookware into food.
  • Iron: Heme vs. Nonheme Copyright 2005 Wadsworth Group, a division of Thomson Learning 10-17%
  • Food Gastrointestinal tract Fe 3+ Phosphates,oxalates (-) (+) ascorbic acid, meat Fe 2+ intestinal mucosa Fe 3+ Fe 3+ + apoferritin blood Fe 3+ +transferrin Ferritin bone marrow liver spleen (storage) heme Fe 3+ +apoferritin ferritin hemoglobin Hemosiderin (storage) Iron absorption
  • Iron in the Body
  • iron absorption is influenced body’s iron stores the type of iron in the diet other dietary factors that either help or hinder iron absorption enhanced by Vitamin C meat diminished by phosphates, oxalates, and tannic acid The greatest influence on iron absorption is the amount stored in your body. Iron absorption
  • Iron Absorption Copyright 2005 Wadsworth Group, a division of Thomson Learning
  • insufficient iron stores insufficient iron intake rapid growth and development failure of iron absorption iron loss Etiology
  • In newborn, the body contains about 0.2-0.5g of iron. Newborn term infants 75 mg/kg A preponderance of iron hemoglobin (75%) first 2-3 months hemoglobin concentration (iron is reclaimed and stored) adult has 5g Insufficient iron stores Etiology
  •  
  • premature low birth weight twins infant with perinatal blood loss Insufficient iron stores the premature or low birth weight infant 64 mg/kg Etiology
  • Iron balance during the first year of life Full-term infant Premature infant Birth 1 year Birth 1 year Weight(kg) 3.3 10.5 1.5 9.5 Blood hemoglobin(g/dl) 20.0 12.3 20.0 12.3 Blood volume(ml) 290 800 135 720 Total hemoglobin(g) 58 98 27 89 Hemoglobin iron(mg) 198 335 90 300 Storage tissue iron(mg) 60 73 27 67 Total body iron(mg) 258 408 117 367 Net positive iron balance 0.4 0.7 (mg/day)
  •   A diet containing 8-15mg of iron is necessary for optimal nutrition (approximately 10% is absorbed) the normal daily excretion of iron < 1mg/d Insufficient iron intake Etiology
  • 1mg/kg/day to a maximum of 15mg/day is required in a normal full-term infant 2mg/kg/day to a maximum of 15mg/day is required in Premature infants Etiology
  • Insufficient iron intake
    • Poor sources of iron
    • The diet (during the period of infancy)
    • milk (cow’s or human’s) contain little iron
    • poverty
    • Malabsorption syndrome
    • loss of appetite
    Etiology
  • Iron content of infant foods Food iron(mg) unit Milk 0.5-1.5 liter Eggs 1.2 each Cereal,fortified 3.0-5.0 ounce Vegetables (strained) yellow 0.1-0.3 ounce green 0.3-0.4 ounce Meats (strained) Beef,lamb,beef liver 0.4-2.0 ounce Pork, liver ,bacon 6.6 ounce Fruits (strained) 0.2-0.4 ounce
  • Rapid growth and development The age of 6 months to 2 yrs is a period of rapid growth and development, correspondingly the infant’s blood volume must be proportionately expanded, the requirement of iron also increased Etiology
  • Iron balance during the first year of life Full-term infant Premature infant Birth 1 year Birth 1 year Weight(kg) 3.3 10.5 1.5 9.5 Blood hemoglobin(g/dl) 20.0 12.3 20.0 12.3 Blood volume(ml) 290 800 135 720 Total hemoglobin(g) 58 98 27 89 Hemoglobin iron(mg) 198 335 90 300 Storage tissue iron(mg) 60 73 27 67 Total body iron(mg) 258 408 117 367 Net positive iron balance 0.4 0.7 (mg/day)  
  • failure of iron absorption
    • Food collocation is not reasonable
    • Chronic diarrhea
    Etiology
  • Iron loss infant during the first 2 months iron loss > iron absorption from the diet intolerance cow’s milk syndrome of sensitivity to cow’s milk 0.7 ml of blood in stool is lost each day (induced by a heat-labile protein in whole cow’s milk) Etiology
  • Iron loss occult bleeding (Chronic iron deficiency anemia) lesion of the gastrointestinal tract peptic ulcer meckels diverticulum polyp hemangioma hookworm infection Etiology
  • Infants at high risk for iron deficiency Increased iron needs Low birth weight High growth rate Chronic hypoxia Low hemoglobin after birth Blood loss Perinatal bleeding Dietary factors Early cow milk intake Early solid food intake Low vitamin C intake Low meat intake Breast-feeding for more than 6 months without iron supplements Low socioeconomic status
  • Causes of Iron Deficiency
  • iron depletion (store) iron deficiency erythropoiesis iron deficiency anemia Clinical manifestation
  • Predisposing age 6 months 3 years Clinical manifestation
  • General manifestation Pallor the most common symptom palpebral conjunctivas mucous membranes of the oral cavity, the nails, palms, the rest of the skin also become pale. Dyspnea on exertion failure to thrive listlessness irritability fatigue dizziness vertigo The nails clubbing and koilo’nychia. Clinical manifestation
  •  
  • Manifestation of extramedullary hematopoiesis hepatosplenomegaly lymphonodes enlarged Clinical manifestation
  • Others Gastrointestinal symptom : Anorexia, dysphagia, pica Cardiovascular symptom : A systolic murmur Tachycardia cardiomegaly congestive cardiac failure There is an increased incidence of infections tuberculosis chest gastrointestinal infections Nervous system : Irritability , decreased attentiveness shorter attention span, associated with behavioural and intellectual deficiencies. Clinical manifestation
  • Behavioural Change Lack of energy , irritability, poor concentration Nervous system Of course these are common problems associated with children that may not always becaused by iron deficiency Clinical manifestation
  • Learning Difficulties Learning difficulties can be present in anemic children, and there is some evidence to suggest that intellectual and physical development may not always be completely reversed when the child’s iron status has been corrected. Nervous system Clinical manifestation
  • red cells microcytic and hypochromic. Laboratory findings
  •  
  • Iron Deficiency Anemia:
  • Iron Deficiency Anemia
    • Both size and color are normal in these blood cells
    • Blood cells in iron-deficiency anemia are small and pale because they contain less hemoglobin
  • IDA
  • Mean corpuscular volume (MCV)<80fl Mean corpuscular hemoglobin (MCH) <26pg Mean corpuscular hemoglobin concentration (MCHC)<31% Red blood cell indices Laboratory findings
    • The reticulocyte count may be normal /slight
    • decrease
    • Nucleated red cells may be present
    • White cells and platelets may normal. severe
    • cases may slightly decreased
    Laboratory findings
  • Serum irons below 9-10.7 umol/L ( normal range is 12.8-31.3) Serum ferritin less than 12ug/l The total iron-binding capacity(TIBC) more than 62.7 umol/L Free erythrocyte protoporphyrin (FEP) more than 0.9umol/L Laboratory findings
  •  
    • Bone marrow :
    • erythroid hyperplasia
    • granulocyte normal
    • megakaryocytes normal
    • < 2 years little or no iron in the
    • form of hemosiderin
    • Stool routine
    Laboratory findings
  • The highest incidence age 6m-3yrs A history of inadequate intake of iron History of chronic malabsorption or infections The clinical manifestation The peripheral blood smear microcytic and hypochromic red cells A good hematopoietic respons after 3-7 days of adminstration of iron. then the red cells and Hb other laboratory examinations : bone marrow serum iron or serum ferritin Diagnosis
  •    Anemia of infection Protein of malnutrition Thalassemia acquired hemolytic anemia Pyridoxine deficiency Sideroblastic anemia lead poisoning Differential Diagnosis
  • Thalassemia Disorders of Globin chain synthesis
    • Imbalance between alpha and beta chain synthesis
    • Results in hypochromic/microcytic anemia
    Alpha Thal: Alpha gene deletions Beta Thal: Many different point mutations Genetics of Thalassemia
  • b -Thalassemia HbA2
  • Mentzer Index
    • MCV/RBC
      • > 13.5 suggestive of iron deficiency
      • < 11.5 suggestive of thalassemia
    • Microcytic, hypochromic form
    • Inherited defect of heme synthesis enzyme
    • High serum and tissue iron levels
    • Buildup of immature sideroblasts
    • — hence the name
    Sideroblastic Anemia
  •  
  • Lead Poisoning
    • A very serious but preventable health problem
    • Nearly 1 million U.S. children under age 6 have elevated blood lead levels
    • Even children who seem healthy may have high levels of lead in their blood
  • Major Source of Lead Poisoning
    • Dust and chips from lead-based paint
      • Children may eat dust that accumulates on hands, toys, furniture, floor, window sills, porches
      • Children may inhale dust or fumes if paint is heated (automobile end gas)
  • lead ≥10ug/dl
    • Encourage breast feeding for infant
    • use an iron-fortified infant formulas
    • Supplement with high in iron food
    • Adequate nursing care and prevention of
    • infectious diseases and diarrhea
    • Cooking with an iron-pot to replace the
    • aluminum-pot.
    Prevention
  • Iron Rich Foods
    • Meats beef, pork, lamb, liver, and other organ
    • meats
    • poultry chicken, duck, turkey
    • fish – shellfish mussels, and oysters, sardines
    • Dark green , leafy vegetables broccoli, kale, turnip greens, and collards Kidney beans, pumpkin seeds, wheat germ, sunflower seeds, lentils, walnuts, parsley, almonds, oats
    • Eat more vitamin C
  • Iron Content Of Some Common Foods Food Quantity Milligrams Of Iron Lean beef 100 grams 4.1 Chicken Breast 100 grams 0.6 Fish 100 grams 0.4 1 medium egg 60 gram 0.8 Baked beans 1/2 cup 1.9 Lentils 1/2 cup 2.5 Wholemeal 1 slice 0.7 Boiled spinach 1/2 cup 2.2 Broccoli 1/2 cup 0.7 Iron fortified baby cereal 15 grams 7.5
    • General therapy
    • Removal of etiological factors
    • Treatment with iron preparation
    • Blood transfusions
    Treatment
  •   Oral preparation of iron It is convenient to give iron in the form of an oral preparation a doses of 4-6mg/kg/day of elemental iron Treatment
  • Which iron form to use?
    • The major factors governing the choice of iron compound include:
      • Bioavailability
      • Organoleptic problems
      • Cost
      • Safety
    • Ideally we should go for a safe, cheap, highly bioavailable iron, which causes no organoleptic side-effects
  • Dose of oral iron preparation   Kind of iron infant children elemental iron Dose/day in 1g Ferrous sulfate 0.15-0.3g 0.3-0.6g 200mg Ferrous fumarate 0.1-0.2g 0.2-0.4g 330mg Ferrous gluconate 0.3-0.6g 0.6-1.2g 115mg ( Ferrous salts are absorbed better than ferric salts) therapy is generally continual 2-3 months after restoration of the Hb to normal.
  • Failure to respond to oral iron: the following reasons should be considered Failure or irregular administration of oral iron; administration verifiable by change in stool color to gray-black Inadequate iron dose   Ineffective iron preparation Persistent or unrecognized blood loss, with the patient losing iron as fast as it is replaced.      Incorrect diagnosis Coexistent disease that interferes with absorption or utilization of iron (infection , hepatic or renal disease …)   Impaired GI absorption (e.g. concurrent administration of large amounts of antacids, which bind iron, as treatment of peptic ulcer )
  • Parenteral iron therapy indicated in children showing intolerance to oral iron reduced iron absorption persistent blood loss their parents are unreliable Treatment
  • The requirement of iron dextran milligrams is calculated as fellows: Total doses (mg) (elemental iron) · kg: body weight · 12.5 is the normal Hb in infant · 3.4 is elemental iron(mg) in 1 gram of Hb · 1.2 means an additional iron supplement of 20% for serum iron. 75 x kg x (12.5-Hb) x 3.4 x 1.2 100 Treatment
  • Iron dextran complex intramuscular ampoule containing 100mg elemental iron in 2ml. administer daily, on alternate days, biweekly. Treatment
  • The good response reticulocyte 48 ~ 72h a peak during the 5th to 7th days falls the normal level after 2-3 weeks Treatment
  • . Iron supplementation should be continued for a minimum of 3 months , not only to correct the hemoglobin but also to replenish the iron stores. Treatment
  • Therapeutic effect observation Response to iron supplements Replenish iron stores 1-3 mo Hemoglobin  4-30 days Reticulocyte  , 5-7d peak 48-72 hr Bone marrow reaction; hyperplasia 36-48 hr Enzyme activity improve 12-24 hr reaction Time
  • Blood transfusion are rarely indicated in iron deficiency anemia, except for severe cases (Hb<60g/l) . Treatment
    • Blood transfusion
      • indication : sever anemia complicated cardia
      • insufficiency or infection
      • Ingredient: concentrated RBC/
      • suspension of RBC
      • amount : Hb <30g/L, 3-5ml/kg;
      • Hb 30-60g/L, 5-10ml/kg
    Treatment
  • I ron deficiency anemia definition I ron’s storage I ron’s absorption I ron deficiency anemia’s etiology T he first good response to iron medication T herapy time QUESTIONS