2. HEMATOLOGY
• Study of blood and blood forming
tissues
• Key components of hematologic
system are:
– Blood
– Blood forming tissues
• Bone marrow
• Spleen
• Lymph system 2
5. ERYTHROCYTES / RED BLOOD CELLS
• Composed of hemoglobin
• Erythropoiesis = RBC production
– Stimulated by hypoxia
– Controlled by erythropoietin (Hormone synthesized in
kidney)
• Hemolysis = destruction of RBCs
– Releases bilirubin into blood stream
– Normal lifespan of RBC = 120 days
9. BONE MARROW
– Soft substance in core of bones
– Blood cell production (Hematopoiesis): The production of all
types of blood cells generated by a remarkable self-regulated
system that is responsive to the demands put upon it.
• RBCs
• WBCs
• Platelets
9
10. LIVER
Receives 24% of the cardiac output
(1500 ml of blood each minute)
Liver has many functions
Hematologic functions:
– Liver synthesis plasma proteins including clotting factors and
albumin
– Liver clears damaged and non-functioning RBCs/erythrocytes
from circulation
11. SPLEEN
• Located in upper L quadrant of abdomen
• Functions
– Hematopoietic function
• Produces fetal RBCs
– Filter function
• Filter and reuse certain cells
– Immune function
• Lymphocytes, monocytes
– Storage function
• 30% platelets stored in spleen
12. DETERMINATION OF RBC INDICES
• RBC count (RBC) - RBC’s / 100 mL of Blood = 4.5-5.0 Million / 100 mL
• Hematocrit (Hct) - % of (RB) Cells By Volume = 36-45%)
• Hemoglobin (Hgb) - mg / 100 ml of Blood = 13-15 mg/dL)
• Mean Corpuscular Volume (MCV)
– Hct/RBC - Normal = 90 (+- 10) cubic microliter
• Mean Corpuscular Hemoglobin (MCH)
– Hgb/RBC - Normal = 30 (+- 3) picograms
• Mean Corpuscular Hgb Concentration (MCHC)
– Hgb/Hct - Normal = 33 (+- 2) %
13. INTRODUCTION
• In megaloblastic anemia,
there is a decrease in red
blood cells.
• The cells are too large and
may be abnormally shaped.
• Having too little of the
vitamins folic acid or B-12 are
common causes of
megaloblastic anemia.
14. DEFINITION
• Megalosblastic anemias are
characterized by the
presence of enlarged red
cells (megaloblasts) due to
the impaired cell division.
Because the erythrocytes
that reach the circulation are
enlarged, a macrocytic and
normochromic anemia
results.
15. CAUSES
There are many causes of megaloblastic anemia. The most
common cause in children is LACK OF FOLIC ACID OR
VITAMIN B-12. Other causes include:
Digestive diseases. These include celiac disease, chronic
infectious enteritis, and enteroenteric fistulas. Pernicious anemia
is a type of megaloblastic anemia. It’s caused when the body
can't absorb vitamin B-12..
Inherited congenital folate malabsorption. A genetic problem
in which infants can’t absorb folic acid.
16. CONT….
• Medicines. Certain medicines, like those that prevent
seizures, can interfere with how folic acid is absorbed.
• Diet. Certain restrictive diets can lead to low levels of folate or
B-12 because the child does not get enough of these
nutrients.
17. PATHOPHYSIOLOGY
Mitosis or cell division can’t occur
the marrow precursors remain enlarged which are termed as MEGALOBLASTS.
Mitosis in the progenitor lines is suppressed
Hyperplasia occurs
Due to Vitamin B12 and Folic acid deficiency
Erythrocyte’s DNA synthesis is affected
19. VITAMIN B12 DEFICIENCY
• Vitamin B12, also known as cobalamin, is not synthesized
in the tissues.
• Thus, the body relies on the dietary intake of meat, liver,
seafood and dairy products to supply our needs.
• The body stores more than a 3-year supply of vitamin B12
in the liver.
20. CLINICAL MANIFESTATIONS
• Weakness
• Listless
• Pale
• Smooth sore red tongue and diarrhea
• Neurologic manifestations (confusion, paresthesia, paralysis,
severe neuropathy)
21. CONTI…
• Pale or yellow skin
• Fast heart beat
• Shortness of breath
• Lack of energy, feeling tired
• Decreased appetite
• Irritability or fussiness
• Hair color changes (rare)
• Stomach upsets, nausea,
diarrhea, gas, constipation
• Trouble walking
• Numbness or tingling in
hands and feet
• Smooth and sore tongue
• Weak muscles
23. • Hemoglobin and hematocrit. This is often the first screening
test for anemia in children. It measures the amount of
hemoglobin and red blood cells in the blood.
• Complete blood count, or CBC. A complete blood
count checks the red blood cells, white blood cells, blood
clotting cells (platelets), and sometimes, young red blood cells
(reticulocytes). It includes hemoglobin and hematocrit and
more details about the red blood cells.
• Peripheral smear. A small sample of blood is examined under
a microscope. Blood cells are checked to see if they look
normal or not.
• Other blood tests. For example, your child may need bilirubin
or other liver tests, folate and B-12 blood tests, and iron
tests.
24. MANAGEMENT
• Vitamin B12 replacement
• Oral supplementation if the cause is inadequate cobalamin intake.
• In cases of defective absorption or absence of intrinsic factor, replacement
is by intramuscular (IM) injection of Vitamin B12.
25. FOLIC ACID DEFICIENCY
Folic Acid is another vitamin that
is necessary for normal red blood
cell production.
It is stored in the body as folates.
The dietary sources of folate are
meats, eggs and leafy vegetables.
Body stores of folic acid provide a
five-month period of tolerance
from proven deficient folic acid in
the diet.
26. COMPLICATIONS
• Problems with growth and development
• Fatigue
• Poor exercise tolerance
• An enlarged heart or heart failure, if the
anemia is severe
27. NURSING MANAGEMENT
• Risk for ineffective tissue perfusion (peripheral) related to decreased
Hb concentration in the blood as manifested by decreased
hemoglobin
• Activity intolerance related to insufficient oxygen delivery to the body
parts secondary to production of abnormally large RBC as evidenced
by body weakness
• Knowledge deficit related to lack of information resources as
manifested by verbalization of situation reflecting ignorance.