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Basic Iron Metabolism
- fetal life
- early wks life
- 2mos of life
- premature infants
transplancental transfer against conc grad, mostly during 3rd trimester.
- typically polycythemic w/total body iron=circ RBC�s
- Above 65 count=could be due to positon
Early Weeks of Life:
dec in hematocrit b/c fetal rbc�s short live & little erythropoesis occurs. Recovered iron stored bone marrow
Two Months of Life:
erythropoesis inc & uses the stored iron in the form new rbc�s. initial iron stores will last until the child is 2.5birth wt. child must take in iron.
become iron def sooner=smaller rbc mass & faster growth rate
early life, iron loss=minimal
Iron Requirements (Elemental)
- Full term infants need approximately 1mg/kg/day
- Premature infants need approximately 2mg/kg/day=b4 37wks
Breast fed infants do not need supplemental iron while the child is exclusively breast fed!
Add Iron between 4 and 6 months=ferisol drops
If iron deficient:Premature infant:
2-4mg/kg/day after 2 mos
If iron deficient:Full term infant:
1-2mg/kg/day after 2 mos
If iron def max dose
- is 15mg of elemental iron in 24 hrs
- Iron deficiency=most common
- hereditary spherocytosis (congenital hemolytic)
- sickel cell
Iron deficiency definition
hematologic, gi, cns ( dec conc, irritability), musc growth
Pertinent Historical Findings/Clinical manifestations:Iron def
asymptomoatic, pallor, fatigue, irritable, dec musc tone, mot development delay & pagophagia (chewing on ice)
Diagnostic Evaulations: Iron Def
Labs: hypochromic, microcytic RBCs, low MCV, low MCH, low serum ferritin, low serum iron, low transferrin saturation, normal to higher reticulocyte count.
Differential Diagnosis:Iron Def
othalassemia, lead poisoning, & chronic inflammation or infection, iron def
Medical Management:Iron def
Treatment: iron supplem
Thalassemia (congenital hemolytic anemia)=Alpha-Thalassemia:definiton
microcytic, hypochromic anemia of variable severity=chromosome 16
inc severity w/each deletion of the four alpha globin genes
Pertinent Historical Findings/clinical symptoms:Thalassemia
- 1 deletion: no symptoms,
- 2 deletions: mild anemia,
- 3 deletions: hemolytic anemia,
- 4 deletions: stillborn � hydrops fetalis
- in more sever ecases folic acid is rec & transfusion may be needed
- TIP: iron supplementation is useless for thalassemia
mild microcytic, hypochromic anemia, unresp to iron tx, elevated hemoglobin A2, asymptomatic=chromosome 11
mod to severe microcytic, hypochromic anemia developoing in 1st yr life as fetal hgb production dec, elevated fetal & hgb A2, HSM, skeletal abnormalities.
Medical Management:Beta Thalassemia
- bone marrow transplantation
- chronic transfusion with iron chelation to prevent iron from getting to high
- Emerging treatments: pharmacologic treatment to manipulate fetal hemoglobin & gene therapy
- Note: if not treated, most children will die w/in the 1st decade of life. It is the most common cause of transfusion dependent anemia in childhood.
Hereditary Spherocytosis (congenital hemolytic anemia):Definition:
normocytic, hyperchromic anemia w/spherocytosis & inc reticulocytes
oprimarily autosomal dominant with a partial deficiency of spectrin, a protein of the red cell membrane=common in European descent
Pertinent historical findings/Clinical manifestations:Hereditary spherocytosis
anemia, jaundice & splenomegaly. Other: gallstones, weakness, fever, abdominal pain & CHF.
Differential Diagnosis:hereditary spherocytosis
- ABO, or Rh incompatibility,
- autoimmune hemolytic anemaia
Medical Management:hereditary spherocytosis
- folic acid,
Sickle Cell Anemia (congential hemolytic anemia)Definition:
deoxygenation leads to polymerization of hemoglobin into long rods that deform the cell into sickle shape.
Sickle cell anemia: Etiology/Pathogenesis
- This leads to a decrease in RBC life span, increase in blood viscosity and may lead to vaso-occlusion.
- Hypoxia, dehydration, hypertonicity all predispose
- Mutation/deletion of hemoglobin gene. Globin genes typically cluster at chromosome 11( Beta-globin) and Chromosome 16 (alpha-globin) HbAS � Trait; HbAC � mild anemia, HbSS or HbS � disease
Sickel Cell Anemia Background:
African, Mediterranean, Middle Eastern or Indian. 1/400 African-American infants are affected. Eight percent of all African-Americans are considered to have the trait.
Sickle cell anemia Pertinent Historical Findings/Clinical Manifestations
- normal birth wt until 3-4mos of life due to high levels of fetal hgb.
- Anemia=present by 1yr.
- most clinical problems are 2nd to chronic hemolytic anemia or the vaso-occlusion.
Central Nervous System:findings w/SCA
CVA (dizz, faint, headaches may be warn signs.strokes have recurrent problems=silent infarctio
cardiomegaly-systolic ejection, murmur, CHF
pulmonary: findings w/SCA
pneumonia, pulm hpt & infarction (acute chest syndrome)=sickle cell crisis
GI: findings w/sca
hepatomegaly, inc LFT�s, jaundice, gallstones
GU: findings w/sca
hypostheuria, polyuria, hematuria, salt losing nephropathy, nephritic syndrome, UTI�s priapism (prolonged erection)
Ortho: findings w/sca
avascualr necrosis of femoral head, osteomyelitis=salmonella
Derm: SCA findings
skin ulcers of low extr=teens typically
Immune: SCA findings
pneumococcus, haemophilus influenzae, and encapsulated organisms are ususally responsible. Bacterial sepsis and meningitis are the most life threatening.
Crises: findings w/sca
- acute chest syndrome
- acute splenic sequestration
- Vaso-occlusive �
- painful, transient, ischemic tissue damage which may be triggered by dehydration, infection, stress
Dactylitis (hand-foot syndrome) �
often 1st sign, fever may be present, Abdominal and musculoskeletal pain are also common=occurs in 50% in age of children b4=3yo
Acute chest syndrome, CVA
Acute Splenic Sequestration �
massive enlargement of spleen due to pooling of rbc�s rapid drop hgb/hct=shock or death. Seen in infants & young children following febrile illness.
sudden shutdown of bone marrow & drop in hct. May be life threating & follows parvovirus b19 infection.
- Labs: normocytic or macrocytic anemia, increased platelets, reticulocytes. Other findings: sickle cells, Howell-Jolly bodies, target cells
- Dx: hemoglobin electrophoresis
Treatment a. Health Maintenance: nutrition, baseline lab studies, immunizations, education & referreals=folic acid 1mgperday, pneumonocal, infleuza vaccines; delayed puberty, short stature & recognize disease sx=fever & pallor. Opthalomogy for retinopathy, echo for tricuspid regurg; nephrology based upon renal fx tests & pulmonalgy for tests
Infections: prevention & early recognition (prophylactic abx)=3mo�s to 2yo they should receive pencillin=125mg ; 2-5 should be 250mg.
Pain: analgesics, hydration, oxygen, abx, transfusion? Problem at capillary level
Transfusion therapy: acute splenic sequestration, aplastic
Other: hydroxyurea (inc fetal hgb), bone marrow transplantation, chemotherapy
- Gene Therapy
- Increasing expression of Hb F
- RNA repair
Transient Erythroblastopenia of Childhood=Definition:
thought to be an autoimmunce disorder resulting in a normocytic anemia w/reticulowyctopenia
fairly common affecting children=6mos to 4yo
transient erythroblastopenia:Pertinent Historical Findings/Clinical Manifestations:
pallor or incidental finding (draw from for another reason & something else comes back)
transient erythroblastopenia:Differential Diagnosis:
Diamond-Blackfan, chronic disorders like hypothyroidism, renal failure, malignancy
transient erythroblastopenia=Medical Management
Treatment: self-limiting=4-8wks after dx
Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD)=definition
osporadic hemolysis assocatied w/infection or ingestion of fava beans or oxidant drugs (aspirin, sulfa, antimalarials)=always comes back****
Glucose6phosphate dehydrogenase def= Etiology/Background:
most common red cell enzyme disorder resulting in hemolysis. X-linked recessive in Africans, Mediterraneans and Asians
G6Dehy=Pertinent Historical Findings/Clinical Manifestations:
hyperbilirubinemia, hemolytic episodes-pallor, jaundice, hemoglobinuria & can be life threatening
Labs:normal initially, hemolysis -> fall Hgb/Hct, Heinz bodies, reticulocytosis, decrease in G6PD activity in erythrocytes, hemogloniuria
- Treatment: prevention: gene therapy trials underway
- Other: Folic Acid, Transfusion of packed RBCs if hemolysis occurs
Idiopathic Thrombocytopenia Purpura=Definition
dec in platelets, acute vs chronic=ITP
most common bleeding do in children- 2 to 5 yo & often follows viral infection=varicella, rubella, measles, Epstein barr (mono). Spleen forms antibodies which results in thrombocytopenia
Idiopathic thrombocytopenia=Pertinent Historical Findings/Clinical Manifestations:
otherwise healthy child w/petechia, ecchymosis & epistaxis.
hemorrhage into vital organs esp intracranial=major worry
Idiopathic thrombo=Diagnostic Evulations
Labs: drop in platelets, platelets are often larger, other tests normal unless hemolyisis has occured
Idiopathci thrombo=Medical Management:
- 1. General � avoid trauma, stop aspirin products, spontaneous recovery w/in 6mos (70 to 80% in acute form)
- 2. Medications � Corticosteroids, Immune Globulin Intravenous, Rho(D) Immune Globulin, platelet transfusion may be indicated
- 3. Surgical: splenectomy only in severe chronic form (pharm support 12mos after dx) or life-threating hemorrhagic complications.
Plumbism � Lead Poisoning=definition
an elevated serum lead level greater than 9mcg/dl; less than or equal 5yo=still developmenting neurologically which impacts
ingestion occurs typically from environmental exposures such as lead-based paint, renovations, nearby industry, food cans (ethnic), leaded crystal, water pipes, certain insecticides
plumbism=Pertinent Historical Findings/Clinical Manifestations:
- 1. Most are asymptomatic
- 2. GI �anorexia, constipation, abd pain, vomiting, diarrhea, FTT, pica (eating non-food)
- 3. Neuro � irritability (school performance), overactivity, lethargy, ataxia, encephalopathy, coma & death=levels typically over 100
- 4. Heme � microcytic anemia, increased free erythrocyte protoporphyrin (FEP) or zinc protoporphyrin
- 5. Skeletal � lead lines on radiographs of long bones
- 1. Screening � all children below 6 yo should be screened at least one time. Screening should begin at 9-12 mos and be more regimented if child is high risk. Capillary (finger) vs. Venous blood (might have to stick twice). Below 9 for cap=nothing above 9 confirm w/venous
- 2. Nutrition �balanced diet, foods rich in iron, VC, Ca2+, low fat
- 3. Hygiene � reg hand washing, hand to mouth activities, clean the toys & stuff animals
- 4. House Cleaning �damp mopping w/high phosphate cleaner
- 5. Abatement=city or state helps to mandate the lead in the home.
plumbism=Medical Management Intervention/Treatment
- 1. Based on classification of VENOUS lead
- 2. Fe supplementation
- 3. Chelation � oral/IV/IM usually indicated for venous lead greater 45mcg/dl=greater than 70 do in hosp setting; encepatholopathy if suspect lead poising.
- 4. New housing is needed
- 5. Intensive follow-up w/specialist