peds hematology Flashcards
1
Q
Define anemia. What is the cutoff [Hgb]
A
reduction in RBC mass or blood hemoglobin concentration
- [Hgb] < 11 g/dL for male and female children < 5 yrs
2
Q
microcytic, hypochromic anemia comprises of what conditions
A
- iron deficiency
- thalassemia
- lead intoxication
3
Q
macrocytic anemia comprises of what conditions
A
- vit B12 and folate deficiency
4
Q
what is fanconi anemia
A
- inherited bone marrow failure syndrome
- autosomal recessive
- defective DNA repair
- 75-90% develop bone marrow failure in the first 10 yrs of life
5
Q
clinical presentation
- progressive pancytopenia
- severe congenital malformations
- abnormal pigmentation of skin
- short stature
- skeletal malformation
- increased incidence of malignancies
A
fanconi anemia
6
Q
what lab findings are typical of fanconi anemia
A
- thrombocytopenia or leukopenia typically occurs first
- followed by anemia -> severe aplastic anemia
- bone marrow hypoplasia or aplasia
7
Q
treatment of fanconi anemia
A
- supportive: treat based on how they present
- anemia: transfusion
- thrombocytopenia: platelet transfusion
- hematopoeitic stem cell transplant: definitive treatment
8
Q
clinical presentation
- peripheral pancytopenia with a hypocellular bone marrow
- fatigue, pallor
- frequent or severe infections
- purpura, petechiae, and bleeding
A
acquired aplastic anemia
- 50% idiopathic
9
Q
what labratory findings are consistent with acquired aplastic anemia
A
- all cell lines are affected early
- anemia, usually normocytic
- leukopenia with marked neutropenia
- thrombocytopenia
- low reticulocyte count
10
Q
what are the leading causes of death in acquired aplastic anemia
A
- overwhelming infection
- severe hemorrhage
11
Q
treatment for acquired aplastic anemia
A
- referral
- Abx for infection
- immunosuppressant agents
- hematopoietic stem cell transplant (HSCT)
12
Q
what is the most common nutritional deficiency in children
A
iron deficiency
- prevalence is greatest among toddlers aged 1-2 yo; higher in african americans and hispanics, and those living in poverty
13
Q
clinical presentation
- pallor
- fatigue, irritability
- delayed motor development
- hx of pica
A
iron deficiency
14
Q
when is anemia first screened for
A
screening for anemia performed at 12 months
15
Q
what are some risks for iron deficiency anemia
A
- prematurity/low birth weight (iron absorbed in 3rd trimester)
- lead exposure
- exlcusive breast feeding beyond 4 mo w/o iron supplementation
16
Q
what labratory findings are consistent with iron deficiency anemia
A
- microcytic, hypochromic anemia
- hemoglobin < 11 g/dL
- ferritin < 12 mcg/L (iron stores will fall first)
17
Q
treatment for iron deficiency anemia
A
- iron 6 mg/kg/d, 3 divided daily doses
18
Q
what are the common causes of vitamin B12 (cobalamin) deficiency
A
- intestinal malabsorption
- dietary insufficiency
19
Q
what are the common causes of folic acid deficiency
A
- increased folate requirements
- rapid growth, chronic hemolytic anemia
- malabsorptive syndromes (celiac disease)
- inadequate dietary intake (rare)
20
Q
clinical presentation
- pallor
- glossitis
- older children
- paresthesias, weakness, or unsteady gait
- decreased vibratory sensation and proprioception on neurologic exam
A
megaloblastic anemia
21
Q
what condition is consistent with large neutrophils that have hypersegmented nuclei
A
megaloblastic anemia
22
Q
treatment of megaloblastic anemia
A
- **must treat vit B12 deficiency to avoid permanent neurological deficits
- B12 and/or folic acid supplementation
23
Q
peripheral smear that shows spherocytes with increased osmotic fragility is consistent with what condition
A
Hereditary spherocytosis
24
Q
what is Hereditary spherocytosis
A
- red cell membrane defect that makes it deformed. When it goes through spleen, RBC get stuck and phagocytized
- type of hemolytic anemia
- see jaundice, splenomegaly, and gallstones
25
treatment of Hereditary spherocytosis
* supportive care +/- RBC transfusion
* may need a splenectomy
26
how is thalassemia diagosed
hemoglobin electrophoresis
27
thalassemia is what type of anemia
* microcytic, hypochromic anemia
* hemolytic anemias
28
thalassemia treatment
* RBC transfusion?
* iron monitoring + chelation
* splenectomy may help (wait till age 3-6 yo)
* hematopoietic stem cell transplant for severe beta thalassemia
29
what is sickle cell disease
* homozygous, Hb SS-hemolytic anemia
* "sickle-shaped" RBCs when deoxygenated
* splenic infarcts -\> functional asplenia
30
chronic hemolysis with vaso-occlusion -\> pain is consistent with what condition
sickle cell disease
31
how is sickle cell disease diagnosed
hemoglobin electrophoresis
32
treatment for sickle cell disease
* avoid precipitating factors
* oxygen
* **hydroxyurea** for painful vaso-occlusive episodes
* stem cell transplant
33
what is G6PD deficiency
* defect in an enzyme in RBC that protects cell from oxidative stress
* **X-linked recessive inheritance**
* **episodic hemolysis** at times of exposure due to
* oxidant stress of infection
* certain drugs and food substances
34
G6PD deficiency is highest among what populations
* african, mediterranean, and asian ancestry
35
clinical presentation
* neonatal jaundice, hyperbilirubinemia
* episodic hemolysis
* pallor, jaundice, hemoglobinuria
G6PD deficiency
* RBC lysis -\> dump of hemoglobin -\> hyperbilirubinemia -\> too much biliruben for liver to handle -\> jaundice
36
peripheral smear showing Heinz bodies is consistent with what condition
G6PD deficiency
37
peripheral smear showing basophilic stippling is consistent with
lead poisoning
38
lead poisoning treatment
chelation
39
what is congential erythrocytosis (familial polycythemia)
* only **RBC** affected (lots of RBC)
* hemoglobin may be as high as 27 g/dL
* concern: blood viscosity and thrombosis
40
clinical presentation
* plethora
* splenomegaly
* HA, lethargy
congential erythrocytosis (familial polycythemia)
41
treatment of congential erythrocytosis (familial polycythemia)
phlebotomy (take blood away)
42
what is secondary polycythemia
* acquired, more common
* **occurs in response to hypoxemia**
* cyanotic congenital heart disease
* chronic pulmonary disease
43
treatment for secondary polycythemia
* correct underlying disorder
* phlebotomy when indicated
44
risk of spontaneous bleeding when platelet count is below
\< 20,000
* nml 150,000 - 400,000 / mm3
45
prothrombin time is a measure of what pathway? what are the factors of that pathway
* PET - \> **extrinsic** and common
* I, II, V, **VII,** X, and **tissue factor**
46
activated partial thromboplastin time (PTT) is a measure of what pathway? what are the factors of that pathway
* PITT: **intrinsic** and common pathways
* I, II, V, **VIII, IX**, X, **XI, XII**
47
what are the factors of the common pathway
* V, X, II (prothrombin), IIa (thrombin); I (fibrinogen)
48
INR (international normalized ratio) is used to monitor
warfarin treatment
49
"bleeding time" function
* measures time for hemostasis
* screens test for platelet dysfunction
* prolonged in platelet disorders (vW disease) and severe thrombocytopenia
50
what is the most common bleeding disorder of childhood
acute idiopathic thrombocytopenic purpura
* most frequent in children 2-5 yo
51
etiology of idiopathic thrombocytopenic purpura
* often follows **viral infection**
* **immune mediated**
* antibodies bind to platelets
52
prognosis of idiopathic thrombocytopenic purpura
* 90% of children will have spontaneous remission
* chronic ITP occurs n 10% of patients
53
clinical presentation
* multiple petechiae
* ecchymosis
* epistaxis
* thrombocytopenia
* normal WBC, normal hemoglobin
* PT and PTT are normal
idiopathic thrombocytopenic purpura
54
treatment of idiopathic thrombocytopenic purpura
* avoid medications that compromise platelet function (NSAIDs, ASA)
* **prednisone**: first line treatment
* IVIG
* splenectomy: emergency
55
what is the most common inherited bleeding disorder
von Willebrand disease
56
how is von Willebrand disease inherited
autosomal dominant
57
what is von Willebrand factor
* a protein that binds to factor VIII and is a cofactor for platelet adhesion to the endothelium
* forms platelet plug
58
clinical presentation
* epistaxis
* menorrhagia
* GI bleeding
* easy bruising
* normal PT, prolonged or normal aPTT
* **Prolonged bleeding time**
von Willebrand disease
59
treatment for von Willebrand disease
* Desmospressin (DDAVP): causes release of vWF and factor VIII from endothelial stores
* vWF-replacement therapy
60
what is Hemophilia A
* factor VIII deficiency (most common)
* X-linked M \> F
61
what is Hemophilia B
* factor IX deficiency
* X-linked: M \> F
62
clinical presentation
* bleeding into joints and muscles
* spontaneous hemarthrosis
* can lead to joint destruction
* normal platelet count, PT, and bleeding time
* prolonged aPTT
Hemophilia
63
treatment for Hemophilia
* Hemophilia A : Desmopressin
* factor replacement (VIII and IX)
64
disseminated intravascular coagulation is triggered by
* sepsis
* trauma and tissue injury
* malignancies
65
pathophysiology of disseminated intravascular coagulation
triggering event -\> widespread activation of coagulation cascade -\> **microthrombi** -\> massive consumption of platelets, fibrin, and coagulation factors -\> **severe bleeding**
66
clinical presentation
* shock
* hematuria, melena, purpura, petechiae
* persistent oozing form needle punctures or other invasive procedures
* evidence of thrombotic lesions
* purpura fulminans
* decreased platelet count
* prolonged aPTT and PT
* elevated D-dimer and fibrin degradation products
disseminated intravascular coagulation
67
the liver produces what factors in coagulation cascade
* prothrombin, fibrinogen
* factors V, VII, IX, X, XII, and XIII
68
what coagulation factors are dependent on vitamin K
* II, VII, IX, and X
69
function of activated protein C
inactivates activated factors V and VIII
70
patients with protein C deficiency can develop what if they are given warfarin
warfarin-induced skin necrosis
71
what is protein S
cofactor for protein C and facilitates the action of activated protein C
72
what is factor V leiden mutation
* point mutation
* factor V becomes resistant to inactivation by activated protein C
73
risk of venous thromboembolism is increased in those with factor V leiden mutation who
* take oral contraceptives
74
what is antithrombin? what happens if there is a deficiency
* inhibitor of thrombin
* deficiency causes venous thromboembolism
75
in patients with antithrombin deficiency, what medication's MOA is affected
Heparin efficiency may be diminished: bc it binds to antithrombin
76
common characteristics of thrombotic disorders
* hypercoagulable
* may see DVTs or PEs
77
treatment for thrombotic disorders
* anticoagulant prophylaxis
* anticoagulant agents
* UFH
* LMWH
* warfarin
78
what is the most common type of small vessel vasculitis
Henoch-Schonlein Purpura
79
what condition often precedes Henoch-Schonlein Purpura
URI
80
what is Henoch-Schonlein Purpura
* deposition of IgA immune complexes
* small vessels of the skin, GI tract, and kidneys
81
clinical presentation
* **palpable purpura**
* arthritis/arthralgias
* abd pain
* renal disease
* normal or elevated platelet count
* antistreptolysin O titer often elevated
* serum IgA elevated
* UA: hematuria, proteinuria
Henoch-Schonlein Purpura
