Hema Flashcards
Progressive drop in Hb over first 2–3 months until tissue oxygen needs are greater than delivery (typically 8–12 weeks in term infants, to Hb of 9–11 g/dL
Physiologic Anemia of Infancy
Physiologic Anemia of Infancy
• Exaggerated in preterm infants and earlier; nadir at _____ to Hb of 7–9 g/dL
3–6 weeks
Reason for IDA in non-BF babies
− Higher bioavailability of iron in breast milk versus cow milk or formula
Infants with decreased dietary iron typically are anemic at_______
9–24 months of age.
MC SSx of Fe deficiency
Clinical appearances—pallor most common; also irritability, lethargy, pagophagia,
tachycardia, systolic murmurs; long-term with neurodevelopmental effects
Lab findings of IDA
− First decrease in bone marrow hemosiderin (iron tissue stores)
− Then decrease in serum ferritin
− Decrease in serum iron and transferrin saturation → increased total iron-binding
capacity (TIBC)
− Increased free erythrocyte protoporhyrin (FEP)
PBS findings in IDA
− Microcytosis, hypochromia, poikilocytosis
− Decreased MCV, mean corpuscular hemoglobin (MCH), increase RDW, nucleated
RBCs, low reticulocytes
Within 72–96 hours—peripheral reticulocytosis and increase in Hb over ____
4–30 days
IDA Tx
Continue iron for ____weeks after blood values normalize; repletion of iron in 1–3
months after start of treatment
8
Lead Poisoning
• Blood lead level (BLL) up to_____ is acceptable
5 μg/dL
_______—gold standard blood lead level
Confirmatory venous sample
Indirect assessments of Pb poisoning—
1
2
- x-rays of long bones (dense lead lines);
2. radiopaque flecks in intestinal tract (recent ingestion)
Labs of Pb poisoning
− Microcytic, hypochromic anemia
− Increased FEP
− Basophilic stippling of RBC
Treatment for Lead Poisoning:
5–14 (μg/dL)
Evaluate source, provide education, repeat blood lead level in 3 months
Treatment for Lead Poisoning:
≥70 μg/dL)
Immediate hospitalization plus 2-drug IV treatment:
– ethylenediaminetetraacetic acid plus dimercaprol
• Increased RBC programmed cell death → profound anemia by 2–6 months
Congenital Pure Red-Cell Anemia (Blackfan-Diamond)
Congenital Pure Red-Cell Anemia (Blackfan-Diamond)
Sx
− Short stature
− Craniofacial deformities
− Defects of upper extremities; triphalangeal thumbs
Congenital Pure Red-Cell Anemia (Blackfan-Diamond)
Labs
− Macrocytosis
− Increased HbF
− Increased RBC adenosine deaminase (ADA)
Congenital Pure Red-Cell Anemia (Blackfan-Diamond)
Other Labs
− Very low reticulocyte count
− Increased serum iron
− Marrow with significant decrease in RBC precursors
Congenital Pure Red-Cell Anemia (Blackfan-Diamond)
Tx
− Corticosteroids
− Transfusions and deferoxamine
MCC of Congenital Pancytopenia
• Most common is Fanconi anemia—spontaneous chromosomal breaks
Physical abn of Fanconi anemia
− Hyperpigmentation and café-au-lait spots
− Absent or hypoplastic thumbs
− Short stature
Labs abn of Fanconi anemia
− Decreased RBCs, WBCs, and platelets
− Increased HbF
− Bone-marrow hypoplasia
Dx of Fanconi anemia
bone-marrow aspiration and cytogenetic studies for chromosome breaks
Cx of Fanconi anemia
increased risk of leukemia (AML) and other cancers, organ complications,
and bone-marrow failure consequences (infection, bleeding, severe anemia
Tx of Fanconi anemia
Corticosteroids and androgens
− Bone marrow transplant definitive
• Transient hypoplastic anemia between 6 months–3 years
− Transient immune suppression of erythropoiesis
− Often after nonspecific viral infection (not parvovirus B19)
Transient Erythroblastopenia of Childhood (TEC)
Recovery period of Transient Erythroblastopenia of Childhood (TEC)
Recovery generally within 1–2 months
Labs of Anemia of Chronic Disease and Renal Disease
Hb typically 6–9 g/dL, most normochromic and normocytic (but may be mildly
microcytic and hypochromic
What is the cause?
•RBCs at every stage are larger than normal; there is an asynchrony between nuclear
and cytoplasmic maturation.
• Ineffective erythropoiesis
MEGALOBLASTIC ANEMIAS
MCC of MEGALOBLASTIC ANEMIAS
Almost all are folate or vitamin B12 deficiency
Labs of MEGALOBLASTIC ANEMIAS
Macrocytosis;
nucleated RBCs;
large, hypersegmented neutrophils;
low serum folate; iron and vitamin B12 normal to decreased; marked increase in lactate dehydrogenase; hypercellular bone marrow with megaloblastic changes
Presentation of Folic Acid Deficiency
• Peaks at 4–7 months of age—irritability, failure to thrive, chronic diarrhea
Causes of Folic Acid Deficiency
Cause—inadequate intake (pregnancy, goat milk feeding, growth in infancy, chronic
hemolysis), decreased absorption or congenital defects of folate metabolism
Hypersegmented neutrophils have ___ lobes
in a peripheral smear.
> 5
• Only animal sources; produced by microorganisms (humans cannot synthesize
Vitamin B12 (Cobalamin) Deficiency
Vitamin B12 (Cobalamin) Deficiency
Sufficient stores in older children and adults for 3–5 years; but in infants born to mothers with deficiency, will see signs in first __
4–5 months
SSx of Vitamin B12 (Cobalamin) Deficiency
Clinical—weakness, fatigue, failure to thrive, irritability, pallor, glossitis, diarrhea,
vomiting, jaundice, many neurologic symptoms
Hereditary Spherocytosis and Elliptocytosis
Abnormal shape of RBC due to ________ → decreased deformability →
early removal of cells by spleen
spectrin deficiency
SSx of Hereditary Spherocytosis and Elliptocytosis
− Anemia and hyperbilirubinemia in newborn
− Hypersplenism, biliary gallstones
− Susceptible to aplastic crisis (parvovirus B19)
Labs of Hereditary Spherocytosis and Elliptocytosis
Labs − Increased reticulocytes − Increased bilirubin − Hb 6–10 mg/dL − Normal MCV; increased mean cell Hb concentration (MCHC
Confirmation of Hereditary Spherocytosis and Elliptocytosis
Confirmation—osmotic fragility test
What is the dx?
− Increased reticulocytes, mild macrocytosis, polychromatophilia
• Diagnosis—pyruvate kinase (PK) assay (decreased activity)
Pyruvate kinase (glycolytic enzyme) deficiency
Tx of Pyruvate kinase (glycolytic enzyme) deficiency
Treatment—exchange transfusion for significant jaundice in neonate; transfusions
(rarely needed), splenectomy
2 syndromes of Glucose-6-phosphate dehydrogenase (G6PD) deficiency
− Episodic hemolytic anemia (most common)
− Chronic nonspherocytic hemolytic anemia
Inheritance of G6PD?
X-linked; a number of abnormal alleles
SSx of G6PD deficiency
Within 24–48 hours after ingestion of an oxidant (acetylsalicylic acid, sulfa drugs,
antimalarials, fava beans) or infection and severe illness → rapid drop in Hb,
hemoglobinuria and jaundice (if severe)
Labs of G6PD deficiency after attack
free Hb and hemoglobinuria, Heinz
bodies, increased reticulocytes
Genetic problem in Sickle Cell Anemia (Homozygous Sickle Cell or S-Beta
Thalassemia)
• Single base pair change (thymine for adenine) at the sixth codon of the beta gene
(valine instead of glutamic acid)
SSx of Sickle Cell Anemia (Homozygous Sickle Cell or S-Beta
Thalassemia)
Newborn usually without symptoms;
development of hemolytic anemia over
first 2–4 months (replacement of HbF);
as early as age 6 months; some children
have functional asplenia;
by age 5, all have functional asplenia
First SSx of Sickle Cell Anemia (Homozygous Sickle Cell or S-Beta
Thalassemia)
First presentation usually hand-foot syndrome (acute distal dactylitis)—symmetric,
painful swelling of hands and feet (ischemic necrosis of small bones)
What are the acute presentation of Sickle Cell Anemia (
° Younger—mostly extremities
° With increasing age—head, chest, back, abdomen
° Precipitated by illness, fever, hypoxia, acidosis, or without any factors (older)
Sickle Cell Anemia
° Infarction of bone and marrow (increased risk of_______
Salmonella osteomyelitis)
Sickle Cell Anemia
_____ (peak age 6 mos to 3 yrs); can lead to rapid death
− Acute splenic sequestration
Altered splenic function → increased susceptibility to infection, especially with
__________
encapsulated bacteria (S. pneumococcus, H. influenzae, N. meningitidis
Aplastic crisis—after infection with _________; absence of reticulocytes
during acute anemia
parvovirus B19
Labs of Sickle Cell Anemia
If severe anemia: smear for target cells, poikilocytes, hypochromasia, sickle
RBCs, nucleated RBCs, Howell-Jolly bodies (lack of splenic function); bone
marrow markedly hyperplastic
Dx for Sickle Cell Anemia
° Confirm diagnosis with Hb electrophoresis (best test)
° Newborn screen; use Hb electrophoresis
Tx for Sickle Cell Anemia
° Immunize (pneumococcal regular plus 23-valent, meningococcal)
° Start penicillin prophylaxis at 2 months until age 5
Folate supplementation
Hydroxyurea
Tx for Sickle Cell Anemia
Bone-marrow transplant in selected patients age ______
<16 years
–deletion of 2 genes
– Common in African Americans and those of Mediterranean descent
– Mild hypochromic, microcytic anemia (normal RDW) without clinical problems
Alpha thalassemia trait
______ deletion of 3 genes; Hgb Barts >25% in newborn period and easily
diagnosed with electrophoresis
HgB H disease:
_______: deletion of 4 genes; severe fetal anemia resulting in hydrops fetalis
Alpha-thalassemia major
Alpha-thalassemia major prognosis
immediate exchange transfusions are required for any possibility of survival;
transfusion-dependent with only chance of cure (bone marrow transplant)
Problem with Beta Thalassemia Major (Cooley Anemia)
Excess alpha globin chains → alpha tetramers form; increase in HbF (no problem
with gamma-chain production)
SSx ov with Beta Thalassemia Major (Cooley Anemia)
• Presents in second month of life with progressive anemia, hypersplenism, and cardiac decompensation (Hb <4 mg/dL)
Labs of Beta Thalassemia Major (Cooley Anemia)
− Infants born with HbF only (seen on Hgb electrophoresis)
− Severe anemia, low reticulocytes, increased nucleated RBCs, hyperbilirubinemia
microcytosis
− No normal cells seen on smear
BMA of Beta Thalassemia Major (Cooley Anemia)
Bone-marrow hyperplasia; iron accumulates → increased serum ferritin and
transferrin saturation
Tx of Beta Thalassemia Major (Cooley Anemia)
− Transfusions
− Deferoxamine (assess iron overload with liver biopsy)
− May need splenectomy
− Bone-marrow transplant curative
SSx of von Willebrand disease (vWD) or platelet dysfunction → _________
mucous membrane bleeding, petechiae, small ecchymoses
SSx of Clotting factors deficiency
deep bleeding with more extensive ecchymoses and hematoma
______—platelet function and interaction with vessel walls; qualitative
platelet defects or vWD (platelet function analyzer)
Bleeding time
_______ is the most common acquired cause of bleeding disorders in children
thrombocytopenia
What lab test
________ from initiation of clotting at level of factor XII through the final clot (prolonged with factor VIII, IX, XI, XII deficiency)
PTT—intrinsic pathway:
What lab test
______measures extrinsic pathway after activation of clotting by thromboplastin
in the presence of Ca2+;
prolonged by deficiency of factors VII, XIII or anticoagulants; standardized values using the International Normalized Ratio (INR)
PT—
________—measures the final step: fibrinogen → fibrin; if prolonged:
decreased fibrin or abnormal fibrin or substances that interfere with fibrin
polymerization (heparin or fibrin split products)
Thrombin time
- X-linked
* Clot formation is delayed and not robust → slowing of rate of clot formation
Hemophilia
Hemophilia
− 2× to 3× increase in ______
− Correction with mixing studies
PTT (all others normal)
Hemophilia
________ sometimes used to diagnose carrier state
° Ratio of VIII:vWF
Hemophilia
_____ increases factor VIII levels in mild disease
DDAVP
• Most common hereditary bleeding disorder; autosomal dominant, but more
females affected
von Willebrand Disease (vWD)
SSx of von Willebrand Disease (vWD)
Clinical presentation—mucocutaneous bleeding (excessive bruising, epistaxis, menorrhagia,
postoperative bleeding)
Labs of von Willebrand Disease (vWD)
Labs—increased bleeding time and PTT
VWD Tx
− Most with type 1 ____ induces release of vWF
− For types 2 or 3 need replacement → _______
DDAVP
plasma-derived vWF-containing concentrates
with factor VIII
Vitamin K is fat soluble so deficiency associated with a decrease in factors _______
II, VII,
IX, and X, and proteins C and S
All clotting factors produced exclusively in the liver, except for ______
factor VIII
Tx of bleeding from liver disease
Treatment—fresh frozen plasma (supplies all clotting factors) and/or cryoprecipitate
(supplies fibrinogen
What condition?
− Typically 1–4 weeks after a nonspecific viral infection
− Most 1–4 years of age → sudden onset of petechiae and purpura with or without
mucous membrane bleeding
− Most resolve within 6 months
Immune Thrombocytopenic Purpura (ITP)
BMA of ITP
Bone marrow—normal to increased megakaryocytes
What shouldnt be given to pts with ITP
Transfusion contraindicated unless life-threatening bleeding (platelet antibodies
will bind to transfused platelets as well)
Treatment of ITP
If very low platelets, ongoing bleeding that is difficult to stop or life-threatening:
– Intravenous immunoglobulin for 1–2 days
° If inadequate response, then prednisone
Treatment of ITP
_____ reserved for older child with severe disease
– Splenectomy
