Hematology

Question 1

What does leukocytosis mean?

What is on the DDx for causing this?

Answer 1

→ increased WBCs (normal range is 5-10)

DDx:

• Platelet clumping/lab error
• Acute infection
• Chronic Inflammation (JIA, Kawasaki)
• Down Syndrome
• Chronic myelogenous leukemia (CML)
• Recent steroid use (40⁺mg/d)

Question 2

Why does steroid use (more than 40mg/d) cause leukocytosis?

Answer 2

causes demargination of WBCs, so more are present in the periphery and picked up on testing

Question 3

What is leukopenia and what is its DDx?

Answer 3

decreased WBCs (under 5)

DDx:

• Post-infectious bone marrow suppression (HIV, Parvovirus, EBV, CMV , Varicella, etc)
• Bone Marrow Failure- Aplastic anemia or leukemia
• Cyclic neutropenia- occurs every 21 days
• Autoimmune neutropenia
• African ancestry

Question 4

Which is almost never seen in pediatrics:

thrombocytopenia or thrombocytosis?

Answer 4

Thrombocytosis (too many platelets, with an increased risk of clotting) is RARE in peds.

Almost exclusively reactive (secondary):

• Infection
• Kawasaki syndrome
• Inflammatory/Autoimmune Disorders
• Trauma
• Post-steroids

Question 5

You incidentally find thrombocytopenia on routine CBC. What symptoms would require you to work up the patient?

Answer 5

problems with bleeding:

nosebleeds,

petechial or purpuric rashes

Question 6

Thrombcytopenia (decreased platelets)

(normal range= 150-400)

Either a “losing problem”, as with immune thrombocytopenic purpura or a “ _______________”

problem (viral suppression of platelet production) or _______________ (AML, CML, aplastic anemia)

Answer 6

“production”

bone marrow failure

Question 7

What CBC values represent microcytic anemia?

What is the most common cause of microcytic anemia (and something that you will treat empirically)?

What do you need to test for at the same time you test for anemia?

Answer 7

MCV under 80

increased RDW says iron deficiency anemia is very likely, RDW is also widened slightly in lead picture

iron-deficiency anemia is MC

should also be testing for lead at a 15-24 month visit

Question 8

If your empiric treatment of microcytic anemia is ineffective when you follow-up in 1 month (and your patient was compliant in taking the 4-6mg/kg/day of ELEMENTAL Iron) what is your next step?

Answer 8

Get additional labs:

serum Fe, ferritin, TIBC

Consider hemoglobinopathies:

get Hgb electrophoresis

Question 9

Your 18mo old, 10kg patient needs to take daily iron.

Provide instructions.

(Dosing=4-6mg/kg/day of ELEMENTAL iron)

125mg of ferrous sulfate is in 1 ml and this contains 25mg of elemental iron

Answer 9

This pt is 22lbs=10kg and has mild anemia, so needs (40mg)

For pharmacist: write→125mg in 1 mL (which contains 25mg of elemental iron), so would have take 1ml, BID

►also needs something for constipation iron will cause (miralax qOD or bran cereal)

►Mix liquid iron with white grape juice or chocolate syrup or spaghetti sauce to make taste better, separate from milk ingestion, helps to take with Vit C (so can give with a few ounces of OJ)

Question 10

What is TIBC and what does it measure?

Answer 10

Total iron binding capacity= TIBC

Measures the amount of a protein (transferrin) in the blood that is capable of transporting iron to RBCs or body stores

Question 11

What is ferritin and why is it important?

Answer 11

ferritin= a protein that stores iron in the liver and spleen. Ferritin is a measure of the body’s iron reserves

Question 12

DDx for normocytic anemia

Answer 12

• Bone Marrow Failure syndromes (Acquired Aplastic Anemia, Leukemia)
• Transient Erythroblastopenia of Childhood
• Chronic Renal Failure
• Anemia of Chronic Inflammation**
• Lead poisoning**
• Hereditary Spherocytosis**
• Sickle cell disease**

**(eventually microcytic)

Question 13

Macrocytic anemias are very RARE in kids. If any otherwise healthy kid has this finding, what two things would you consider first?

Answer 13

celiac disease

or

drinking goat’s milk (and not cow’s)

Question 14

If a patient has normocytic anemia- what lab test should we have requested to determine in she has a losing or a production problem?

Answer 14

A reticulocyte count

(over 3% means she has a loosing problem)

a reticulocyte is an immature RBC, and, in a losing problem, these will be pushed out into the periphery in greater numbers

Question 15

Why do we screen all kids for iron deficiency and lead poisoning between 15-24 months?

Answer 15

This is the time that children are putting things in their mouth and can ingest lead.

High risk for iron deficiency with failure to add sufficient solid foods into diet.

Being iron deficient appears to increase the risk of lead toxicity

Question 16

Design an evaluation and management for a pediatric patient with unusual bleeding

Answer 16

Should get a CBC on most kids with petechial rash, but if just on face/neck/upper chest may just be from extensive vomiting/etc

-If on trunk or widespread→deserves CBC

ITP level is less than 20,000 platelets (read as 20 on CBC)

→ Hold off on sports for that week.

→RTC: nosebleeds, worsening petechiae, fever, gum bleeds

Question 17

What dietary changes should happen with kids in the second year of life?

What is a common failure with this change that leads to the child having anemia?

Answer 17

Should have transitioned from formula or breast milk to whole milk @ 12-16oz/day with an increase in solid foods to provide their necessary nutrients

Some kids fail to include the solid foods and stay on a 40-48oz/day liquid diet of just whole milk→ will suppress their appetite for solid foods, and whole milk does not contain iron or other necessary nutrients

This kids are usually chubby, and may be pale depending on their degree of anemia.

Question 18

What is the relationship between Hgb and Hct?

Answer 18

hematocrit often mirrors hemoglobin,

(i.e. if the hemoglobin is low the hematocrit is low)

Hct= % of whole blood that consists of RBC’s with their Hgb

Hgb= just this compenent of lysed RBCs

In iron-deficiency anemia, the hemoglobin will be low, and the hematocrit will also be low because the RBC’s are smaller due to the smaller hemoglobin, and therefore the RBC’s are taking up less space in the whole blood.

Question 19

What might Hbg and Hct values look like in an iron deficient patient who is also acutely dehydrated?

Answer 19

the hemoglobin will still be low but the hematocrit may be normal due to the decrease in overall blood volume from the dehydration

Question 20

What are normal ranges on a CBC?

Answer 20

WBC- (5-10) *used in PC to monitor for infection

RBC- (4.0-5.5)

Hgb- (9.5-14) *whether or not anemic, renal EPO fxn

Hct- (30-40) *Hct is usually about 3x the Hgb value

MCV- (80-100) *micro/normo/macrocytic anemia

MCH- (27-31) *hypo/normo/hyperchromic anemia

MCHC- (32-36)

RDW- (11-14.5) *variation is size of RBCs

Plt- (150-400)

MPV- (7.4-10.4)

Question 21

Most people need little dietary iron because:

Answer 21

When a RBCs “life” is over, after ~120 days, the spleen removes it from circulation.

(in spleen) Hgb⇒heme + globin

Heme⇒ iron + bilirubin

Iron is recycled with some being transferred, via transferrin, directly back to the bone marrow and some being stored as ferritin in the liver and spleen.

Question 22

Exceptions to the “closed system” of iron recycling occurs in these types of patients:

Answer 22

1. young children who are growing and therefore increasing their blood volume rapidly
2. menstruating women who are losing blood monthly
3. patients who are losing blood in the periphery due to pathologic processes (eg hemorrhage)