Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Anemias in children Anemia… … abnormal low hemoglobin, hematocrit or RBC count, lower than the age-adjusted reference range for healthy children. Anemia… … abnormal low hemoglobin, hematocrit or RBC count, lower than the age-adjusted reference range for healthy children. Etiologic classification I Impaired red cell formation A/ Deficiency Decreased dietary intake Increased demand Decreased absorption Increased loss B/ Bone marrow failure Failure of a single or all cell lines Infiltration C/Dyshematopoietic anemia II Blood loss III Hemolytic anemia Corpuscular (membrane, enzymatic or hemoglobine defects) Extracorpuscular (immune, idiopathic) Diagnosis of Anemia detailed history careful physical examination peripheral blood smear red cell morphology MCV RDW (red cell distribution width) WBC and platelet morphology Additionally: -bone marrow evaluation -additional testing History - Diet (iron , folate, vitB12 intake, onset of hemolysis after certain foods –e.g.,fava beans) - family history (transfusion requirements of relatives, splenectomy, gallblader disease) - environmental exposures (lead poissoning) - symptoms (headache, exertion dyspnea, fatigue, dizziness, weakness, mood or sleep disturbances, tinnitis) - melena, hematemesis, abdominal painchronic blood loss Physical Examination Pallor (skin, oral mucosa, nail beds) Jaundice -hemolysis tachycardia tachypnea orthostatic hypotension venous hum systolic ejection murmur peripheral edema? Splenomegaly? Hepatomegaly? Glossitis? gingival pigmentation? Adenopathy? Facial, extremity examination Peripheral Blood Components important! Different values dependent on age! RBC Hgb HCT MCV – 80 – 100 fl/L (a calculated value) MCH RDW Reticulocyte Count MCV for Characterize Anemia (>85fl) *Macrocytic Low(<70 fl) *Hypochromic/Microcytic -Iron deficiency anemia -Thalassemia -Sideroblastic anemia -Chronic infection -Lead poisoning -Inborn errors of Fe metabolism -Severe malnutrition -Copper deficiency Normal newborn Increased erythropoesis Post splenectomy Liver disease Aplastic anemia Megaloblastic anemia Down S. Obstructive jaundice Normocytic Acute blood loss Infection Renal failure Connective tissue disorders Liver disease Disseminated malignancy Early iron deficiency Aplastic anemia Bone marrow infiltration Dyserythropoietic anemia Megaloblastic anemia Presence the megaloblasts in the bone marrow and macrocytes in the blood In > 95% occurs as a result of folate and vitamin B12 deficiency Deficiencies of ascorbic acid, tocopherol, thiamine may be related to megaloblastic anemia Dietary vitamin B12 (cobalamine) is required from animal sources (meat and milk) Causes of vitamin B12 deficiency I Inadequate dietary intake (<2mg/day) –malnutrition, veganism, maternal deficiency II Defective vitamin B12 absorption Failure to secrete intrinsic factor Failure to absorption in small intestine III Defective vitamin B12 transport IV Disorders of vitamin B12 metabolism (congenital, acquired) Folic acid deficiency One of the most common micronutrient deficiences in the word (next to iron deficiency) Component of malnutrition and starvation Women are more frequently affected than men Folate sufficiency prevents neural tube defects Low mean daily folate intake is associated with twofold increased risk for preterm delivery and low infant birth weight Causes of folic acid deficiency Inadequate intake (method of cooking, special diet, goat’ milk) Defective absorption (congenital or acquired) Increased requirements (rapid growth, chronic hemolytic anemia, dyserythropoietic anemias, malignant disease, hypermetabolic state, cirrosis, post –BMT) Disorders in folic acid metabolism (congenital, acquired) Increased excretion Clinical features of cobalamine and folate deficiency Insidious onset: pallor, lethargy, fatigability, anorexia, sore red tongue and glossitis, diarrhea History: similarly affected sibling, maternal vitamin B12 deficiency or poor maternal diet Vitamin B12 deficiency: signs of neurodevelopmental delay, apathy, weakness, irrability, athetoid movements, hypotonia, peripheral neuropathy, spastic paresis Megaloblastic Anemias: Clinical Findings •Anemia is slow to develop •Fatigue • Weakness • Yellow color •Weight loss •Glossitis Megaloblastic Anemia: Lab Features: Hematology Macrocytic, normochromic anemia Increased MCH: due to large cell volume Normal MCHC RBC, HGB, Hct decreased Granulocytes and Thrombocytes are affected as well. Granulocytes are hypersegmented Megakaryoctyes are abnormal resulting in thrombocytopenia Megaloblastic Anemia: Lab Features: Peripheral blood Triad of oval macrocytes, Howell-Jolly bodies and hypersegmented neutrophils Anisocytosis, Poikilocytosis RBC’s are fragile, lifespan is shortened and many die in the bone marrow which causes ↑ LDH Megaloblastic Anemia: Lab Features: Misc Bone marrow Hypercellular with megaloblastic erythroid precursors M:E ratio decreased Chemistries Vitamin B12 Folate Methylmalonic acid (MMA) Homocysteine Lactic dehydrogenase(LDH) Diagnosis Red cell changes: Hgb usually reduced, MCV increased to levels 110 – 140fl., MCHC normal, in blood smear many macrocytes and macro-ovalocytes, anisocytosis, poikilocytosis, presence of Cabot rings, Howell-Jolly bodies, punctate basophilia White blood cell count reduced to 1500 – 4000/mm3, neutrophils show hypersegmentation (>5 lobes) Platelets count moderately reduced (50,000 – 180,000/mm3) Bone marrow: megaloblastic appearance Serum vitamin B12 values lowered (normal 200 – 800 pg/ml) Serum and red cell folate levels – wide variation in normal range; less than 3 ng/ml -very low, 3-5 ng/ml –low, >5-6 ng/ml normal, in red cell:74-640 ng/ml Schilling urinary excretion test – measurement of intrinsic factor availability and absorption of vitamin B12 Treatment Vitamin B12 deficiency Prevention in cases of risk of vitamin B12 deficiency Treatment 25 – 100µg vitamin B12 Folic acid deficiency Correction of the foliate deficiency (100-200µg/day) Treatment of the underlying causative disorder Improvement of the diet to increase folate intake Megaloblastic Anemia: Causes of Vitamin B 12 deficiency Folate deficiency Drugs Myelodysplastic syndromes Acute leukemia Megaloblastic Anemias: Deficiency of Vitamin B12 Vitamin B12 (cyanocobalamin) deficiency 1. Inadequate dietary intake a. B12 is found in food of animal origin: red meat, fish, poultry, eggs, dairy products Megaloblastic Anemias: Deficiency of Vitamin B12 2. Malabsorption a. Pernicious anemia Caused by gastric parietal cell atrophy which causes decreased secretion of intrinsic factor (IF). IF is necessary for B12 absorption. Atrophy due to immune destruction of the acid-secreting portion of the gastric mucosa Onset is usually after age 40, primarily women Affects people of Northern European backgrounds Neurologic problems Schilling test used for diagnosis Schilling test Establishes the cause of vitamin B12 deficiency Test performed in two parts If parts one & two abnormal: Pernicious anemia If part one only abnormal: malabsorption B12 Malabsorption causes (con’t) Gastrectomy Blind loop syndrome c. d. bacteria use up the B12 Fish tapeworm= Diphyllobothrium latum d. completes for B12 Other Causes for B12 Deficiency 3. Drugs a. b. c. Alcohol Nitrous oxide Antitubercular drug Megaloblastic Anemia: Folic Acid (Folate) deficiency 1. Inadequate dietary intake a. Poverty b. Old age c. Alcoholism Megaloblastic Anemia: Folic Acid (Folate) deficiency 2. Malabsorption a. Ileitis/Crohn’s disease b. Tropical sprue c. Blind loop syndrome d. Nontropical sprue a. b. Gluten-sensitive enteropathy Childhood celiac disease Megaloblastic Anemia: Folic Acid (Folate) deficiency 3. Increased requirement a. Pregnancy a. There is increased demand during pregnancy and should be supplemented prior to and during pregnancy. Deficiency during pregnancy can cause neural tube defects in utero. b. Infancy c. Hematologic diseases that involve rapid cellular proliferation such as sickle cell anemia Hemoglobin values vary with age Age Hb (gm/dL) Newborn (cord blood) 13.8-20.0 MCV= 96 -116 Reticulocytes 37% Infancy 2-3 months 3-6 months 6-12 months 9.0 (term) 8.5 (low birth wt.) 9.5 10.0 Child 12-24 months > 24 months 10.5 11.5 Adolescence > 13 years 12.0 (female) 13.5 (male) Differential Diagnosis of Anemia •Divide into groups by size of cell (MCV) Macrocytic Microcytic Normocytic Fe-def Acute blood loss Newborn Thalassemia Liver disease Liver disease Sideroblastic Renal disease Hypothyroidism Lead toxicity Infiltrated marrow Splenectomy Hgb E TEC Trisomy 21 Inborn errors Connective tissue Reticulocytosis Copper def. Aplastic Anemia Anemia/MDS Aplastic Atransferrinemia Vit B12/Folat Differential Diagnosis of Anemia • Consider increased destruction versus decreased production based on reticulocyte count Production Dietary(Fe,B12,Folate) Aplastic Anemia Diamond-Blackfan TEC Bone Marrow infiltrate Destruction Hemoglobin Enzyme defects Membrane defects Immune-mediated 19 mo old male noted by his grandmother to be pale and fussy. Described as very picky, his diet is mainly string cheese, mac & cheese and milk. The child appears in no distress. He is slightly tachycardic with normal heart rhythm, no gallop, +systolic murmur, normal BP and good peripheral perfusion. CBC shows Hb=5.0 gm/dl, MCV 52fL, retic 1.6%. What is the most appropriate clinical management? 1) Refer immediately to the closest hospital for 10cc/kg PRBC transfusion. 2) Schedule a slow transfusion with 5cc/kg of PRBC then start supplementation with oral iron. 3) Start the patient on a daily children’s chewable vitamin with Fe. 4) Obtain nutrition consult and start oral Fe at 3-6 mg/kg elemental Fe daily. Which of the following sets of labs are consistent with iron deficiency anemia? 1) ↑ RDW, ↓ RBC#, ↑ MCV 2) Normal RDW, ↑ RBC#, ↓ MCV 3) ↑ RDW, ↓ RBC#, ↓ MCV Thal trait vs. Fe-deficiency •Remember, in thalassemia trait, all red cells are very small (↓ ↓ MCV), but they’re all the same size (nl RDW), and there is no production problem (nl to ↑ RBC). There is marked discrepancy between Hgb value and MCV, whereas in Fe-def, these two values tend to go down at a similar rate.