Hematology Flashcards
1 g of hemoglobin holds how much oxygen?
1.34 mL
Primary sites of hematopoiesis in utero
Yolk sac <6 wks
Liver 6-22 wks
Bone marrow >22 wks
Alpha-2 beta-2 Hemoglobin
Adult hemoglobin
Alpha-2 gamma-2 Hemoglobin
Fetal hemoglobin
Fetal hemoglobin
Alpha-2 Gamma-2
Favors transfer of oxygen from maternal to fetal blood
60-80% of hemoglobin in newborn
Disorders affecting betaglobin do not affect neonates
Erythropoietin
Produced in liver in fetus and newborn
Primary hormone regulating erythropoiesis
Transitions to kidney
Why are neonates less responsive to heparin?
Inadequate antithrombin III
Increased clearance
Increased binding of heparin to plasma proteins
Increase concentration of fibrinogen
Genetic disorder associated with ribosomal 60 S subunit dysfunction
Shwachman-Diamond syndrome
Most common Hematologic abnormality in Schwachman diamond
Cyclical neutropenia
Alloimmune hemolysis and maternal RBC antigens
Most -> least affected/severe
c > E > C
Kell > Daffy > Kidd > MNS
Father intermittently cyanotic with cyanotic newborn
NADH methemoglobin reductase deficiency
Respond to methylene blue
How much iron is needed for each gram of hemoglobin?
3.47 mg
Why do we use irradiated blood transfusions?
Prevent graft versus host disease
Why do we use leukocyte-reduced blood for transfusions?
Decreased febrile non-hemolytic transfusion reactions
Decreased CMV transmission
Decreased HLA alloimmunization
Why do we used washed RBCs for blood transfusions?
Decreased risk for hyperkalemia
Favorable features for neuroblastoma
Prenatal diagnosis
Liver/skin/bone metastases
DNA hyperploidy
No MYCN amplification
What RBC enzyme defect can give a false positive NBS result for galactosemia?
G6 PD
Causes of Purpura fulminans
DIC
Protein C or protein S deficiency
Factor V Leiden mutation
Absolute contraindications for anticoagulation
CNS surgery or birth ischemia within 10 days
Active bleeding
Invasive procedures within three days
Seizures within 48 hours
Relative contraindications to anticoagulation
Platelet < 50 Fibrinogen <100 INR >2 Severe coagulation deficiency Hypertension
How much bilirubin does 1 g of albumin bind?
7-8 mg
Which form of Crigler Najjar syndrome responds to phenobarbital treatment?
Type 2
Which parts of the brain are affected by kernicterus?
Basal ganglia Hippocampus Subthalamic nuclei Globus pallidus Cerebellum
How does phototherapy decrease indirect bilirubin?
Geometric photoisomerization (4Z/15Z -> 4E/15Z, 4Z/15E, 4E/15E) Intramolecular cyclization (lumirubin formation, most effective) Bilirubin oxidation
What affects the effectiveness of phototherapy?
Wavelength (Blue/green, 425-475 nm)
Irradiance (Energy output, 30W/cm2/nm)
Body surface area exposed
Distance from light to baby
Normal blood smear looks like…
Zone of pallor 1/3 size of RBC Minimal variation in size Visible platelets Normal segmented neutrophils RBC is 2/3 size of normal lymphocyte
Siderocyte
RBC containing granules of iron that are not part of hemoglobin
Howell-jolly bodies
Inclusions of nuclear chromatin
Elliptocytes
Elliptical shape
Spherocytes
Decreased central pallor
What does an eosinophil look like on a blood smear?
Reddish colored, dramatic granules
What does a monocyte look like on a blood smear?
Large cell with one large nucleus inside
What does a basophil look like on a blood smear?
Purple granules
What does a hypersegmented PMN look like on a blood smear?
Many nuclei strung together
Pelger-Huet anomaly
Leukocytes with dumbbell shaped bilobed nuclei
Increased risk of Wilms tumor
Beckwith Weidemann syndrome
Denys-Drash syndrome
Pearlman syndrome
WAGR syndrome
When is cyanosis observed?
> 3-5g of reduced Hgb/ dL capillary blood present
Vitamin K dependent clotting factors
Disco 1972
10, 9, 7, 2, protein c, protein s
Patience with Shwachman-Diamond Syndrome are at increased risk of?
Myelodysplastic syndromes and leukemia
Skeletal abnormalities in Shwachman-Diamond syndrome?
Metaphyseal dystosis
Thoracic dystrophies
Low turnover osteopenia
Symptoms of Shwachman-Diamond syndrome
Bone marrow failure
Pancreatic dysfunction
Recurrent infections
Skeletal abnormalities
Symptoms of hemophagocytic lymphohistiocytosis
Fever Hepatosplenomegaly Jaundice Lymphadenopathy Elevated ferritin Elevated triglycerides Pancytopenia
