Pedi Hematology Flashcards
(130 cards)
1
Q
Polycythemia vs anemia
A
- Polycythemia—an above average increase in the number in the number of red cells in the blood.
- Anemia—reduction in the number of red blood cells.
2
Q
Normal WBC count
A
5,000-10,000
3
Q
Main function of neutrophils
A
phagocytosis
4
Q
Main function of eosinophils
A
allergic reactions
5
Q
Main function of basophils
A
inflammatory reactions
6
Q
Main function of monocytes
A
phagocytosis & antigen processing
7
Q
Main function of lymphocytes
A
Humoral immunity (B cell) and cellular immunity (T cell)
8
Q
Difference between location of hematopoeisis from neonates to older kids
A
- At birth, blood cell production takes place in almost every bone of the body.
- As children age, only certain bones retain their hematopoietic activity
- Sternum
- Ribs
- Pelvic and shoulder girdles
- Vertebrae
- Hips
9
Q
Difference between hemoglobin from neonates to older kids
A
Fetal hemoglobin (higher affinity for O2) is present in decreasing amounts after birth with normal hemoglobin levels gradually increasing.
10
Q
Difference between WBCs from neonates to older kids
A
WBC count highest at birth
by one week of age, levels stabilize
11
Q
PLTs and clotting factors in newborns vs older kids
A
- Platelet values in newborns are lower than in older children.
- Levels of many clotting factors, particularly those requiring Vitamin K for activation (Factors II, VII, IX, X and anticoagulant factors-proteins C&S) are lower in infants
12
Q
What is bilirubin?
A
by-product of RBC destruction resulting from breakdown of the hemoglobin in the RBCs.
13
Q
How is bilirubin produced?
A
by the reticuloendothelial system.
14
Q
How is bilirubin removed?
A
Removed by the liver, which excretes it into bile, giving bile its pigmentation.
15
Q
Two types of bilirubin
A
- Direct or conjugated
- Protein bound
- Indirect or unconjugated
- Circulates freely in the blood until it reaches the liver.
- In the liver, conjugated with glucuronide transferase then excreted into the bile.
16
Q
What is jaundice?
A
clinical sign of hyperbilirubinemia
Excessive amounts of bilirubin that seep into the tissues causing the skin to become icteric (have a yellow hue).
17
Q
Relationship between level of visible jaundice and bilirubin level
A
do not accurately correlate so best to get a bilirubin level.
18
Q
What causes hepatocellular jaundice?
A
Results from injury or disease of liver cells
Viral hepatitis, cirrhosis, Mono
19
Q
What causes obstructive jaundice?
A
Due to blockage of bile or hepatic ducts
Usually from stones or neoplasms
20
Q
What causes hemolytic jaundice?
A
- Overproduction of bilirubin resulting from hemolytic processes that produce high levels of unconjugated bilirubin.
- Hemolytic diseases of the newborn
- Rh or ABO incompatibility
- Pernicious or Sickle Cell Anemia
- Transfusion Reactions
- Crigler-Najjar Syndrome
- Genetic deficiency of hepatic enzyme needed for the conjugation of bilirubin.
21
Q
What causes nonconjugate elevations of bilirubin?
A
- Hemolytic anemias
- Trauma with large hematomas (birth trauma)
- Hepatitis
- cirrhosis
22
Q
What causes conjugate elevations of bilirubin?
A
Pancreatic cancer
Hepatitis
cirrhosis
23
Q
Risk factors for developing severe hyperbilirubinemia
Major Risk Factors
A
- Jaundice in the first 24 hours of life
- Blood group incompatibility
- Gestational age less than 37 weeks
- Previous sibling with phototherapy
- Cephalohematoma or significant bruising
- Exclusive breastfeeding (not going well or significant weight loss)
24
Q
Risk factors for developing severe hyperbilirubinemia
Minor Risk Factors
A
- Gestational age 37-38 weeks
- Jaundice observed before discharge
- Previous sibling with jaundice
- Male gender
- Macrosomic infant of diabetic mother
- Maternal age >25
25
Jaundice: F/U after hospital D/C
before 24h of age
f/u by 72 hours of age
Should obtain weight, % change from birthweight, adequacy of intake/output. (\>10%)
26
Jaundice: F/U after hospital D/C
between 24 and 47.9 hours of age
by 96 h of age
Should obtain weight, % change from birthweight, adequacy of intake/output. (\>10%)
27
Jaundice: F/U after hospital D/C
by 48-72 h of age
f/u by 120 hours
Should obtain weight, % change from birthweight, adequacy of intake/output. (\>10%)
28
Labs for jaundice
* Total and Direct Serum Bilirubin levels
* Blood type (ABO, Rh)
* Direct Antibody Test (Coombs test)—looks for antibodies on the surface of RBCs that may destroy RBCs
* In certain situations:
* Albumin (with exchange transfusions)
* CBC with diff
* Reticulocyte count
## Footnote
*Usually start w/direct & total bili, if keeps going up, add others*
29
How is level of risk determined for jaundice?
* determined by the infant’s age in postnatal hours.
* Infant’s should be designated as high. medium, or low risk
30
Janudince: implications of higher risk?
* The higher the risk level, the more at risk the infant is for developing bilirubin encephalopathy and needing medical interventions.
## Footnote
*Kernicterus – can result in all kinds of long term learning problems*
31
Tx options for elevated bilirubin
* **Phototherapy**: lowers bili by transforming bilirubin into water soluble isomers that can be eliminated w/o conjugation in the liver. Light delivered via fluorescent or halogen bulbs.
* **Watch and wait** - also an option
* **Exchange transfusion**
32
How is dose determined for phototherapy?
by wavelength and intensity of light, BSA exposed to light, distance between light and infant
33
3 Key points from AAP guidelines on hyperbilirubinemia
* Visual estimation of jaundice may lead to errors.
* Interpret all bilirubin levels according to infant’s hours in age.
* Infant’s less than 38 weeks are at higher risk for developing hyperbilirubinemia
34
AAP breastfeeding guidelines for hyperbilirubinemia
* Mothers should nurse their infants 8-12 x/day for the first several days.
* Poor caloric intake and/or dehydration associated with inadequate breastfeeding may contribute to the development of hyperbilirubinemia.
* Recommends against routine supplementation of the non-dehydrated breastfed infant with water or dextrose water: doesn't prevent or help hyperbilirubinemia!
35
What is transcutaneous bilirubin?
amount of bilirubin that has moved from the serum into the tissue
36
advantages of transcutaneous bilirubin
* no need to draw serum
* TcB determined to be 100% sensitive and 66% specific when compared to TSB – w/in 10 days
* Many facilities limit the use of TcB to infants \<10 days old.
37
Disadvantages of transcutaneous bilirubin
* Dermal thickness & melanin content of the skin may impact TcB measurements.
* TcB could affected by site tested
* **Consider TSB level for TcB over 22 mg/dL**
38
Best and worst sites for TcB
* Forehead (before hospital d/c) and sternum have the best correlation between TcB and TSB. Heel, back, and thighs did not correlate well *(low blood flow)* (El-Behbishi, 2009)
* Avoid testing skin that is bruised, has a birthmark, or is covered with hair. *(decreased efficacy)*
39
Rule of thumb lower limit Hb for anemia?
for children ages 12 months to 6 years:
11 + (0.1 x age in years)
40
What causes physiologic anemia of infancy?
* Iron added to fetal stores during the third trimester
* After birth, erythropoietin synthesis abruptly decreases in response to higher oxygenation of tissues.
* Fetal RBCs have shortened life span
* Erythropoietin naturally stimulated and RBC production increases and hemoglobin levels increase.
41
What causes IDA?
* Decrease from blood loss
* Increased rate of destruction (hemolytic anemia, blood transfusion reactions)
* Impaired RBC production (aplastic anemia, renal disease)
* Inadequate nutritional intake of iron
* Excessive Cow’s milk *– ca++ may block Fe absorption. Micro-bleeds in gut.*
* Malabsorption *(e.g., kid w/celiac who had low Hb)*
42
IDA - full term infants- how long do iron stores from mother last?
about 4-6 months after birth.
43
Risks for IDA in infants
* **Premature** infants: fewer iron stores so that may become iron deficient earlier in life (anemia of prematurity).
* **Multiples** or babies born in quick succession: may also have fewer iron stores and become iron deficient earlier.
* **SGA**
* Perinatal blood loss
* Subsequent iron loss due to hemorrhage
* Infants that do not consume adequate solids after 4-6 months of age and are fed only breast milk or non-iron fortified formula
* Increased physiologic demands (such as rapid growth periods).
* **Pica**
* **Increased lead levels**
* **Adolescence**: rapid growth + poor nutrition, menorrhagia
44
What is microcytic anemia and what causes it?
* usually a defect in hgb synthesis
* When the body senses a drop in iron levels; decreases hgb production
* Cells become microcytic and hypochromatic
* causes: iron deficiency anemia, lead poisoning (inhibits synthesis of hgb); thalassemia trait
45
What is normocytic anemia and what causes it?
* Increased destruction or decreased production of RBCs
* Maybe seen with pancytopenias and chronic hemolytic anemias (SCD)
* Anemia of chronic illness (HUS; autoimmune hemolytic anemia; G6PDH)
* cells may be normocytic and normochromatic
46
What is macrocytic anemia and what causes it?
* Rare in Children in US
* Vitamin B12 and folate deficiencies
* May be seen in children with hypothyroidism.
47
Anemia: what might you see in Hx?
* PMH-anemia, splenectomy, sickle cell trait
* FMH—sibling with anemia
* Nutritional History—mother’s diet if breastfeeding; intake of meat; green leafy vegetables; WIC?
* ROS-extremity pain, blood loss, extensive bruising, petechiae, travel, infection exposure, and drug use
48
Anemia: what might you see on PE?
* Growth Charts *(IDA would take awhile to affect growth)*
* Vital signs-blood pressure; heart rate, respiratory rate
* Eye blinks (Lozoff, 2010) *slower eye blinks*
* Pallor, jaundice, petechiae, bruising, murmurs, adenopathy, organomegaly, congenital anomalies
49
When should we screen for IDA?
* Infants: after 6 mo (after 4 if premature)
* 9-12 mo then 6 mo later
* Preschool: annually from 2-5years
* School age: only at risk
* Adolescents: girls Q5 years
* Chronic illness that may result in anemia: as indicated
50
How is IDA Dxed?
* Diagnosed by CBC and clinical presentation; Hgb less than 11g/dL
* RBCs microcytic, hypochromic
* Mean Corpuscular Volume—low
* Mean Corpuscular Hemoglobin—low
* Red Cell Distribution Width—elevated
* Ferritin, Serum iron, Transferrin—low
* TIBC—elevated (total iron binding capacity – trying to grab more!
* May test stool for occult blood—esp in infants consuming cow’s milk
* Consider a blood lead level—IDA increases intestinal lead absorption
51
Mgmt of IDA
* **3-6mg/kg/day** of elemental iron with vitamin C juices *(enhance uptake)*
* Dietary counseling-Protein (needed for blood cells); FA to help convert iron from ferritin to hemoglobin
* Don’t take with dairy, coffee, tea, bran whole grains
* Recommend high fiber diet, prune juice or prescribe stool softener for constipation *(or they will stop giving)*
52
Food high in heme iron sources
* Clams 3oz 23.8mg
* Chicken liver 3oz 9.9mg
* Beef liver 3oz 5.6mg
* Beef 3oz 2.5mg
* Chicken (dark) 3oz 1.1mg
* Pork 3oz 0.9mg
* Fish 3oz 0.8mg
53
Food high in non-heme iron sources
* Oatmeal (fortified) 1cup 14.0mg
* Tofu (raw) ½ cup 6.7mg
* Wheat germ (toasted) ½ cup 5.1mg
* Apricots (dehydrated0 ½ cup 3.8mg
* Lentils (cooked) ½ cup 3.3mg
* Prunes (uncooked) ½ cup 2.3mg
* Raisins ½ cup 1.6mg
54
AAP recommendations: breastfeeding infants and iron supplementation
* *Exclusively breastfed infants* should be supplemented with **1mg/kg** of oral iron beginning at 4 months of age until iron fortified foods are introduced.
55
AAP recommendations: whole milk
No whole milk until 12 months of age.
56
AAP recommendations: red meat
Red meats should be introduced early (6 months of age). Need 11mg/day iron.
57
AAP recommendations: iron supplementation for toddlers (1-3 yrs)
**7mg/day** of iron.
Best through diet but supplements acceptable.
58
AAP Recommendations: FF infants and iron supplementation
Formula fed infants will have their iron needs met by standard iron fortified formula.
59
AAP recommendations for IDA: Preterm infants and iron supplementation
Preterm infants should have iron intake **2mg/kg/day** through 12 months of age. Supplement by one month of age for those fed human milk.
60
AAP recommendations: when should universal screening for IDA be done?
12mo - Hb
Consider additional screening tests—serum ferritin, c-reactive protein, reticulocyte hemoglobin, transferrin
61
IDA
Iron Rx for infants / toddlers
* Fer-In-Sol Drops
* 75mg (15mg elemental Fe)/1.0ml
* 3-6mg elemental Fe/kg/24 hours QD-TID
* Re-check in 1 month
* Warn parents that stools may be dark
* Iron (liquid) may stain teeth
62
IDA
Iron Rx for older children + education on absorption
* 60-100mg of elemental iron divided twice daily (for anyone over 20kg)
* Ferrous sulfate 325 mg tablets contain 65mg elemental iron and should be given once or twice daily depending on the severity of the IDA.
* Absorption takes place in duodenum and is enhanced by acidic environment (take with a small amount of orange juice).
63
USPSTF 2015 recommendation on screening for IDA and routine iron supplementation in kids 6-24mo
Grade of I
improves hematologic values but not clinical outcomes
64
Current reference level for lead poisoning
5mcg/dL
but _No safe levels of lead has been identified_
65
Universal screening for lead levels
1-2 yo
66
Lead Poisoning-Causes
* Pica
* Renovated homes especially homes built before 1978
* Peeling paint
* Parental occupations—demolition, construction
* Parental hobbies—stained glass making
67
Lead Poisoning Treatment
**Treatment is to remove child from source**
Encourage diet high in Fe++ and Ca++ (no studies to confirm)
68
Tx if lead levels in a child are over 45 mcg/dL
* hospitalize/chelation. *Main lead chelators:*
* Succimer (Chemet)—oral chelator
* Calcium EDTA—IV chelator *(not made so much anymore, hard to find)*
* British Anti-Lewisite (BAL)—IM for levels \>70 *(stops brain herniation)*
69
Lead: when does health dept have legal obligation to become involved?
15-20 mcg/dL
70
Why is Glucose 6 Phosphate Dehydrogenase-G6PD deficiency (X-linked recessive) assoc w/anemia?
* Most common red cell enzyme defect that causes hemolytic anemia
* protects RBCs against oxidative stress
* Results in Episodic hemolysis
71
What triggers hemolytic anemia in G6PD deficiency?
* Usually infection, food (fava beans--*Favism*) or drug induced
* aspirin, sulfonamide antibiotics, anti-malarials
72
How is hemolytic anemia in G6PD deficiency treated?
avoid triggers; self-limiting
73
What is spherocytosis?
Autosomal dominant
Spectrin deficiency in RBC membrane → Cells have spherical shape → Cells sequestered and hemolyze in spleen → Growth failure, splenomegaly; jaundice
74
Tx for spherocytosis?
Treatment is splenectomy (does not change cell shape & puts kids at risk for infection)
75
Tx for macrocytic / megablastic anemia?
* Folic acid oral supplements
* Monthly IM injection of Vitamin B12
76
Two types of thalassemias
Alpha and Beta
77
What populations are prone to thalassemias?
Mediterranean, Middle Eastern, Asian, African populations
Autosomal recessive
78
What is beta-thalassemia?
(Cooley’s Anemia)
Decreased or absent production of Hgb A; to compensate body produces fetal hemoglobin—fragile, easily destroyed, shortened life span.
79
Sx of beta thalassemia
pallor, FTT, hepatosplenomegaly, anemia \<6g/dL
80
Tx for beta thalassemia
Exchange transfusions, splenectomies, bone marrow transplantations (treatment of choice)
81
Sx of alpha thalassemia
* May be a carrier and be symptom free.
* More advanced disease may have anemia and splenomegaly
* Alpha Thalassemia major frequently results in death.
82
Tx of alpha thalassemia
May be treated with transfusions but successful bone marrow transplant is the only cure.
83
What is sickle cell dz?
* Do not form Hgb A, have Hgb S
* Membranes have different amino acid (valine vs. glutamic acid)
* Ischemia and vaso-occlusive crisis
* Autosomal recessive disorder
84
Sickle cell trait: Sx
usually symptom free but may have problems when under severe stress, high altitudes, or with anesthesia
85
Sequelae to sickle cell dz
* Hand-Foot Syndrome
* Sequestration crisis-manifested by pain
* Functional asplenia by age 6--infection risk
* Vaso-Occlusive crisis; micro-infarctions; ischemia
* Acute chest syndrome (2-4 years of age) – clogged vessels leading to lungs
* Stroke (11% before age 14 years)
* Priapism
* Necrosis of femoral head
86
Hgb and RBCs in SSD
Hgb 5-9g/dL; shortened RBC life-15 days (normally 120 days)
87
Prophylaxis for infants and toddlers w/SSD?
* PCN 125mg BID from 2 mos-5 years—because bacterial infection are the leading cause of death
* 23 valent-pneumococcal @ 2 years old
88
SSD with for fever, pneumonia, painful crisis
Emergency admission
89
Main Txs for vaso-occlusive crisis in SSD?
* Main treatments: Oxygen, fluids, analgesia, transfusions, BMT
* Transfusions put at risk for iron overload
90
How is SSD usually Dxed?
* Usually diagnosed by newborn screening
* Confirmed by hemoglobin electrophoresis
* Obtain a detailed history about nutrition, past crises, precipitating events, medical treatments and home management.
91
Mgmt of SSD
* Monitor development/school progress
* Assess parental and child’s knowledge
* Follow growth parameters closely (FTT)
* Do pain assessment at each visit
* Ask about support; comfort therapies (massage, touch, distraction, praying)
* Avoid all contact sports d/t risk of splenic rupture; medical ID
92
What is neutropenia?
ANC of \<1500
* Absent or defective granulocyte stem cells
* Decreased marrow release
* Increased neutrophil destruction
93
How is ANC calculated?\*\*
WBC x % (segs + bands)
## Footnote
Differential WBC=3600; segs=20; bands=5; lymphs=60; mono=10
ANC = 3600 x 0.25 = 900
94
Tx neutropenia
Treatment depends on the underlying cause
G-CSF increases WBCs
95
most common cause of isolated neutropenia
Viral infections or medications
## Footnote
*can also be caused by: severe bacterial infections, meabolic dz, immunodeficiency*
96
Malignancy and **isolated** neutropenia
not usually associated
97
What is Neutrophilia?
ANC \> 8,500
98
What causes neutrophilia?
* infection, inflammatory conditions (JRA, IBD, Kawasaki), asplenia
* Acute stress conditions—trauma, burns, surgery, emotional upset, electric shock
* Medications—corticosteroids, lithium, epinephrine
* Tumors involving the bone marrow
99
Predisposing factors to leukemia
infection, radiation or chemical exposure, genetic
100
S/Sx of leukemia
Fever, pallor, bruising, joint pain/limp
Lymphadenopathy and hepatosplenomagaly
101
Leukemia: labs
CBC with diff shows pancytopenia
102
Leukemia Tx
Chemotherapy/radiation/BMT
103
What is thrombocytopenia?
Platelet count below 150,000
104
What causes thrombocytopenia?
* Injury of bone marrow resulting in inability to produce platelets
* Loss or excessive dilution of blood
* Pooling of blood in the spleen
* Immune response (idiopathic thrombocytopenic purpura)
105
What is hemophilia?
* Hereditary bleeding disorder
* Hemophilia A is a factor 8 deficiency-85%
* Hemophilia B is a factor 9 deficiency-15%
* A& B are X-linked recessive disorders but 1/3 are new mutations
* Hemophilia C is a factor XI deficiency and is autosomal recessive; affects males and females equally
106
Onset of hemophilia sx
Most children do not have symptoms until after 6 months of age
107
S/S of hemophilia
* May have bleeding into joints (hemarthrosis); deep tissue hemorrhage
* Will limit child’s ROM
* May have extensive bleeding after circumcision or minor traumas; easy bruising; nosebleeds, hematuria)
* Bleeding into neck, mouth, chest--serious
108
Hemophilia lab results
* Lab data will show low levels of factor VIII or IX; prolonged Partial Thromboplastin Time (PTT)
* Prothrombin time (PT), Thrombin time (TT); fibrinogen, and platelet counts are normal
109
Tx of hemophilia
* DDAVP which stimulates release of stored factor VIII. *(same thing used to treat enuresis)*
* If severe, may have factor concentrate at home. *(to start w/injury)*
110
PC Mgmt of hemophilia
* Monitor Growth/development (gross motor, fine motor, coordination)
* Family coping mechanisms—feelings of guilt *(esp any genetic issue)*, need for respite care
* Obtain complete medical history—episodes of bleeding/family history
* Assess for pain, joint swelling, hematuria
* Anticipatory guidance about keeping kids safe: helmet; area rugs *(cause falls in everyone)*; sharp edges
111
Cautions in PE / care of kids with hemophilia
* Avoid taking rectal temps or suppositories
* Check blood pressure infrequently
* Avoid injections/venipunctures
* Do not give aspirin containing products
* Be very gentle with otoscope
* Advise adolescents to shave with electric razors only
* Encourage non-contact sports such as swimming
112
What is Von Willebrand's?
And is it inherited or acquired?
* Deficiency in Von Willebrand’s factor—a plasma protein and the carrier for clotting factor VIII; gene on chromosome 12
* Usually autosomal dominant; _most common_ hereditary bleeding disorder
* May be acquired with cardiac/renal disease; lupus; hypothyroidism
113
Von Willebrand's: lab results
decreased vonWillebrand’s factor levels; prolonged bleeding time and prolonged PTT
114
Von Willebrand's: presenting sx
Presenting symptoms may be gingival bleeding, epistaxis, ecchymosis, prolonged bleeding with lacerations or dental procedures, menorrhagia
115
Von Willebrand's: Tx
* DDAVP used to promote release of Von Willebrand’s factor
* Avoid aspirin or other platelet inhibiting medications
116
What is thrombosis?
* A deficiency in anti-coagulant proteins
* Malfunction of factor 5
* May be autosomal dominant or homozygous recessive
117
Tx thrombosis?
* Heparin and coumadin
* Major vessel thrombosis—streptokinase, urokinase, TPA
118
What is ITP?
and is it hereditary or acquired?
* Increased destruction of platelets in the spleen due to a binding of autoantibodies to platelet antigens. Platelet destruction exceeds platelet production
* Most common _acquired_ bleeding disorder
119
Peak age of ITP
5.5 (1 - 10 years)
120
How does ITP usually begin?
Usually follows viral infection (cause unknown); 1-4 weeks
121
Sx of ITP
bruising, mucosal bleeding
122
ITP: lab results
CBC/diff reveals normal hemoglobin and WBCs but decreased platelets
123
ITP: what to do if PLTs below 20,000
monitor for intracranial hemorrhage
124
Prognosis for ITP?
* 80% have spontaneous resolution within 6 months; if persists \>1 yr, splenectomy since spleen is destroying platelets
125
Tx of ITP
Steroids or immune globulin
126
What is Henoch-Schonlein Purpura?
inflammation of the small blood vessels
127
Henoch-Schonlein Purpura: age and gender
\<10yo
Males more than females
128
Henoch-Schonlein Purpura: cause
unknown but follows viral infection
129
S/S Henoch-Schonlein Purpura
Purpuric lesions, joint and abdominal pain
Blood in stool/hematuria; nephritis
130
Dx and mgmt of Henoch-Schonlein Purpura
No defining lab test; Self-limiting; may use steroids to control pain
