Hematology

Question 1

Mean corpuscular volume (MCV)

Answer 1

= SIZE

Expression of the average volume and size of individual erythrocytes

-cytic = size

Can be microcytic, normocytic, or macrocytic

Question 2

Microcytic

Answer 2

~ 80 fl

Question 3

Normocytic

Answer 3

~ 80 - 100 fl

Question 4

Macrocytic

Answer 4

~ 100 fl

Question 5

Mean corpuscular hemoglobin concentration (MCHC)

Answer 5

= COLOR

Expression of the average hemoglobin (Hgb) concentration or proportion of each EBC occupied by Hgb as a percentage.

More accurate than mean corpuscular hemoglobin (MCH)

Can be Normochromic, hypochromic, or hyperchromic (although most text deny the existence of hyper= because it is impossible for a RBC to be too red

Question 6

Normochromic

Answer 6

32-36%

Question 7

Hypochromic

Answer 7

< 32%

Question 8

Hyperchromic

Answer 8

> 36%

Question 9

Mean corpuscular hemoglobin (MCH)

Answer 9

= WEIGHT

Expression of the average amount and weight of Hbg contained in a single erythrocyte; not as useful

Normal: 26-34 pg

Question 10

Red cell distribution width (RCDW)

Answer 10

Red cell size variation (ie anisocytosis)

Differentiates b/w iron deficiency anemia (IDA), thalassemia, and anemia of chronic disease (ACD)

IDA: increased
Thalassemia: normal or slightly increased
ACD: normal

Question 11

Reticulocyte count

Answer 11

Number of new, young RBCs in circulation
*immature cells

Expressed as a % (normal is 1-2%)

Index of bone marrow health and response to anemia: immune system is trying to fix anemia when it is pushing these out

Anemia d/t:

1. Bone marrow failure
2. Hemorrhage or hemolysis

Response to therapy

Question 12

Anemias

Answer 12

Conditions caused by various disorders of the RBC count, quality of hemoglobin and/or volume of packed RBC

Anemias are classified according to RBC size (MCV) and hemoglobin concentration (MCHC)

Question 13

Causes of microcytic/hypochromic anemia in children

Answer 13

IDA
thalassemia
lead poisoning

Question 14

Causes of normocytic/normochromic anemia

Answer 14

ACD
acute blood loss
early IDA

Question 15

Causes of macrocytic/normochromic anemia in adults

Answer 15

Vitamin B12 deficiency
folate deficiency
pernicious anemia

Question 16

Iron Deficiency Anemia

Answer 16

Microcytic, hypochromic anemia d/t an overall deficiency of iron

Caused by decreased iron intake, increased needs, or slow GI blood loss

Question 17

In infancy, iron deficiency is d/t

Answer 17

an inadequate intake of iron (low iron formula, solely breast fed) or micro hemorrhage from the gut d/t early intake of whole milk (before the age of 9 months - cannot break down the protein)

Question 18

In toddlers, iron deficiency is often d/t

Answer 18

an increased reliance on whole milk at the expense of solid foods

Question 19

In adolescence, iron deficiency is d/t

Answer 19

dieting practices that contribute to an inadequate intake of iron, specifically in girls after menarche

Question 20

S/S Iron Deficiency Anemia

Answer 20

Severity depends on the degree of anemia!

• easy fatigability
• palpitations, SOB on exertion
• lethargy
• HAs
• Pica
• delated motor development
• pale, dry skin and mucous membranes
• tachycardia
• tachypnea
• postural hypotension in severe anemia
• brittle hair
• flat, brittle or spoon shaped nails

Question 21

Labs/diagnostics for Iron Deficiency Anemia

Answer 21

CBC with retic count will show:

Low: 
Hgb and Hct
MCV (microcytic)
MCHC
RBCs
serum ferritin < 30 mcg.L
serum iron

Increased:
red blood cell distribution width (RCDW)
total iron binding capacity

Reticulocyte count will be low in cases of inadequate iron intake or elevated in cases of blood loss

Question 22

Management of Iron Deficiency Anemia

Answer 22

Goal: correct underlying cause

A medicinal iron supplement is require while the cause if being managed and should be continued until the resolution of the underlying process

Question 23

Elemental iron treatment in Iron Deficiency Anemia

Answer 23

1. Treat with elemental iron high dose 3-6 mg/kg/day in 1-3 doses until Hbg normalizes.
2. Then replace iron stores with dosage of 2-3 mg/kg/day for 4 months (all RBCs have been replaced)
3. Then continue with 1 mg/kg/day

Take with OJ to increase absorption

Question 24

Thalassemia

Answer 24

A group of hereditary disorders that are characterized by an abnormal synthesis of alpha (four genes) and beta (two genes) goblin chains.

One ore ore of each gene can be missing.

Type is determined by which genes are missing (alpha vs. beta thalassemia)

Severity depends on number of genes affected – missing 3 or more, will likely need blood transfusions every month for rest of life

Question 25

Causes/Incidence of Thalassemia

Answer 25

1. Second most common cause of microcytic anemia | 2. Autosomal recessive genetic disorder - both parents carry the gene

Question 26

S/S of Thalassemia

Answer 26

Varies from asymptomatic to severe S/S of anema - pale or bronze color to skin - tachycardia - tachypnea - hepatosplenomegaly - frontal bossing

Question 27

Physical exam findings of Thalassemia

Answer 27

1. Prenatal diagnosis 2. Newborn screening **required 3. Infancy: FTT/irritability, splenomegaly, pallor/severe anemia 4. Older child: bony changes, splenomegaly, iron overload d/t multiple transfusions

Question 28

Labs/diagnostic for Thalassemia

Answer 28

``` CBC: Decreased - HGB - MCV (microcytic anemia) - hypo chromic RBCs ``` Increased: - Reticulocyte count - ferritin - total bilirubin ***Hemoglobin electrophoresis!! To make DIAGNOSIS

Question 29

Management of Thalassemia

Answer 29

Refer to hematologist

Question 30

Sickle Cell Anemia

Answer 30

An anemia in which abnormal hemoglobin (due to DNA point mutation) leads to CHRONIC HEMOLYTIC anemia and results in a variety of severe clinical consequences. Peak incidence of infection is between 1-3 years of age

Question 31

Causes/Incidence of Sickle Cell Anemia

Answer 31

Autosomal recessive disorder in which Hgb S develops instead of Hgb A. The patient is homozygous for Hgb S (Hgb SS) Most prevalent in persons of African or African American ancestors; Hbg S gene is carried in 8% of AA: Incidence is 1:400 Patients who have heterozygous genotype (Hgb AS) are generally clinically asymptomatic (unless become hypoxic) but are carriers.

Question 32

Symptoms of Sickle Cell Trait (Hgb AS)

Answer 32

Patients usually have no clinical symptoms. May experience acute painful symptoms under extreme conditions such as exertion at high altitudes.

Question 33

Symptoms of Sickle Cell Anemia (Hgb SS)

Answer 33

- Sudden, excruciating pain d/t a vast-occlusive crisis usually in the back, chest, abdomen, and long bones. * clot -- ischemia -- PAIN -- tissue damage - low grade fever - predisposing factors may be present (ie infection, physical or emotional stress, blood loss)

Question 34

Physical exam findings of Sickle Cell Trait

Answer 34

These patients are clinically normal with no abnormal exam findings

Question 35

Physical exam findings of Sickle Cell Anemia

Answer 35

- chronically ill in appearance - jaundice - retinopathy - delayed puberty - hepatosplenomegaly (spleen usually not palpable in the adult) - enlarged heart with hyper dynamic precordium - systolic murmur - fatigue - tendency toward more frequent infections (which also aggravates crisis)

Question 36

Labs/diagnostics for Sickle Cell Anemia

Answer 36

- hematocrit 20-30% - irreversibly sickled cells on peripheral blood swear (5-50% total) *** - nucleated RBCs (immature red cells) - increased reticuloycytosis (10-25%; immature red cells without nuclei) - target cells (abnormal RBCs) - Howell-Jolly bodies (asplenic conditions) - increased WBCs characteristically elevated to 12,000-15,000 per microliter - indirect bilirubin elevated - platelets may be elevated (>400,000) = thicker blood **Hemoglobin electrophoresis to MAKE DIAGNOSIS Children with sickle cell trait may have episodes of gross hematuria and inability to concentrate the urine d/t renal tubular damage

Question 37

Management of Sickle Cell Anemia

Answer 37

1. Collaboration with a hematologist!! 2. Maintained chronically on folic acid supplementation. 3. Cornerstone of therapy is to prevent episodes and to provide support during the crisis episode - Keep adequately hydrated - Ensure adequate oxygenation - Analgesics for pain control - Antibiotics for associated infection - Transfusions and/or exchange transfusions for intractable crisis and as a preventative measure for clients undergoing anesthesia 4. Hydroxyurea 35 mg/kg/day to stimulate fetal hemoglobin (Hgb F), which does not sickle 5. Immunize with Pneumovax (PS-23) and confirm hepatitis B immunity 6. Provide or refer for genetic counseling.

Question 38

Hemophilia A (X-linked Recessive)

Answer 38

Deficiency of factor VIII (8) Occurs in 1:7,000 males (males only) Frequency of female carriers is about 1:3,500: - 25% risk of having an affected son with each pregnancy - 25% risk of having a carrier daughter - 25% chance of having a healthy, non-carrier daughter or son Severe form occurs in about 48% of cases

Question 39

Typical findings of Hemophilia A (X-linked Recessive)

Answer 39

Phenotypically normal at birth Bleeding tendency: ranges from spontaneous bleeding to bleeding after trauma *Find often during circumsicion, but can also screen for in prenatal screen/do embryo selection

Question 40

Treatment of Hemophilia A (X-linked Recessive)

Answer 40

Infusions of recombinant factor prophylactically or only when a bleed occurs

Question 41

Lead Poisoning

Answer 41

A chronic disease that results from the toxic accusation of lead int he body that leads to iron deficiency anemia (IDA). Centers for Disease Control and Prevention (CDC) definition of lead poisoning is a level > 5 mcg/dl. - Can occur via ingestion or inhalation - Highest prevalence is among poor, inner-city children, and those living in old housing

Question 42

Common sources of Lead Poisoning

Answer 42

- Paint and paint dust (houses prior to 1978; mandates laws require lead free paint!) - Contaminated soil - Gasoline emissions - Food and drinking water - Mexican Americans, Asian, Indian, or other ethnic folk remedies

Question 43

S/S of Lead Poisoning

Answer 43

- vague: GI symptoms - severe: lethargy, difficulty walking, neuropathies - HA - Burtonian lines: bluish discoloration of gingival border !! Blue line on the gum line d/t oxidization of the lead - ataxia - papilledema

Question 44

General Assessment for Lead Poisoning

Answer 44

1. Medical and developmental history (mouthing and pica history) 2. Environmental history 3. Nutritional history 4. Physical exam

Question 45

Environmental history for Lead Poisoning

Answer 45

- paint and soil exposure - residence: year <1978 and condition - outside play - control of dust and dirt - family members' behaviors, occupations - family members' hobbies (fishing, ceramic work, stain glass, and hunting) - exposure to imported food, folk remedies, pottery, metal vessels

Question 46

Nutritional history for Lead Poisoning

Answer 46

- diet history - evaluate the child's iron status by using the appropriate lab tests - ask about history of food stamps or participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)

Question 47

Venous Blood Level Concentrations for Lead Poisoning Classification

Answer 47

Class I: Level <10 mcg/dl Class IIA: Level 10-14 mcg/dl -- refer to hematologist Class IIB: Level 15019 mcg/dl Class III: Level 20-44 mcg/dl For all the above, try to fix the exposure (minimize or eliminate source) Class IV: Level 45-69 mcg/dl -- recommended chelation therapy*** Class V: Level > 70 mcg/dl -- hospitalize for chelation, hydration, and close observation

Question 48

Management of Lead Poisoning

Answer 48

Observe for hemoglobinopathies, impaired renal function, or Vitamin D deficiencies

Question 49

Leukemias

Answer 49

A group of malignant hematological diseases in which normal bone marrow elements are replaced by abnormal, poorly differentiated lymphocytes known as blast cells #1 childhood cancer

Question 50

Acute lymphocytic leukemia (ALL)

Answer 50

Accounts for ~ is 75% of cases Peak incidence around 4 years of age Occurs more frequently in boys than girls More common among Caucasian children Easiest to treat and high survival rate

Question 51

Acute myelogenous leukemia (AML)

Answer 51

Accounts for ~ 20% of all leukemia Occurs primarily in infants and older children Hard to treat, lower success rates, increased secondary malignancies

Question 52

S/S of Leukemias

Answer 52

``` Anemia Pale Listless Irritable Chronically tired History of repeated infections Bleeding such as epistaxis, petechia, and hematoma Lymphadenopathy and hepatosplenomegaly Bone and joint pain ```

Question 53

Labs/diagnostics for Leukemia

Answer 53

1. CBC with differential WBC, platelet, and reticulocyte counts - thrombocytopenia is present is up to 85% of cases, and anemia is usually present 2. Peripheral smear may demonstrate malignant cells (blasts). 3. Bone marrow will show the poorly differentiated blast cells that have been replacing the healthy bone marrow tissue. **Bone marrow aspiration + biopsy to DIAGNOSE.

Question 54

Management of leukemia

Answer 54

1. Referral to an oncologist | 2. Family support