3. Anemia
Anemia comes from the Greek word ( ναιμία)(an-haîma)
meaning "without blood”. It is a deficiency of red blood cells
(RBCs) and/or hemoglobin.
Anemia is a hematologic condition in which there is
quantitative deficiency of circulating hemoglobin
(Hb), often accompanied by a reduced number of
(erythrocytes).
• Usually associated with:
▫ decreased levels of hemoglobin or hematocrit
▫ Abnormal hemoglobin may give appearance of anemia
(methemoglobin).
Classified as:
▫ Moderate (Hb 7-10 g/dl) or
▫ Severe (Hb <7g/dl).
4. Anemia
Deficiency in the oxygen-carrying capacity of the blood
due to a diminished erythrocyte mass.
Two general forms of anemia:
• Absolute Anemia (decrease in red cell mass) and
• Relative Anemia (increased plasma volume gives
appearance of anemia).
May be due to:
Erythrocyte loss (bleeding)
Decreased Erythrocyte production
low erythropoietin
Decreased marrow response to erythropoietin
Increased Erythrocyte destruction (hemolysis)
5. Anemia
Anaemia affects roughly a third of the world's
population; half the cases are due to iron deficiency.
It is a major and global public health problem that
affects maternal and child mortality, physical
performance, and referral to health-care professionals.
Children aged 0–5 years, women of childbearing
age, and pregnant women are particularly at risk.
Several chronic diseases are frequently associated
with iron deficiency anaemia—notably:
chronic kidney disease,
chronic heart failure,
cancer, and
inflammatory bowel disease.
6. Considerations by Age, Sex, and
Other Factors
Newborns <one week old, hemoglobin : 14-22 g/dl.
By six months of age, hemoglobin :11 - 14 g/dl.
Between 1 year and 15 years of age :11-15 g/dl.
Normal adult hemoglobin depends on gender:
♀ 12-16 g/dl
♂ 14-18 g/dl
In geriatric age group, men and women have same
hemoglobin range: 12-16 g/dl.
6
7. Considerations by Age, Sex, and
Other Factors
Normal ranges do depend on patient populations.
Other factors influencing “normal” hemoglobin
include:
▫ Environment: elevation of plains Vs mountains
▫ Physical Health: e.g. lung or kidney disease
▫ Nutritional deficiencies
▫ Blood loss
▫ Bone marrow replacement
▫ Chemicals / Radiation
7
10. Special Considerations in Determining
Anemia
Acute Bleed
Drop in Hgb or Hct may not be shown until 36 to 48 hours
after acute bleed (even though patient may be
hypotensive)
Pregnancy
In third trimester, RBC and plasma volume are
expanded by 25 and 50%, respectively.
Labs will show reductions in Hgb, Hct, and RBC count,
often to anemic levels, but according to RBC mass, they
are actually polycythemic
Volume Depletion
Patient’s who are severely volume depleted may not
show anemia until after rehydrated
11. 11
Classification of Anemias
• Have a variety of ways - depending on criteria
used:
▫ Functional
▫ Morphological
▫ Clinical
▫ Quantitative
12. 12
Functional
Classification of Anemias
• Decreased RBC production (hypoproliferative)
▫ Defective hemoglobin synthesis
Fe deficiency
B12 deficiency
Folate deficiency
▫ Impaired bone marrow or stem cell function, as in
leukemia
• Increased RBC destruction, as in sickle cell
anemia or hemolytic anemia
• Combination of the two (sometimes called
“ineffective erythropoiesis”)
13. 13
Morphological
Classification of Anemias
• Morphological based on color and sizes of
RBCs
▫ Normochromic Normocytic
▫ Normochromic Microcytic
▫ Normochromic Macrocytic
▫ Hypochromic Microcytic
14. 14
Clinical
Classification of Anemias
• According to their associated causes:
▫ Blood loss
▫ Iron deficiency
▫ Hemolysis
▫ Infection
▫ Nutritional deficiency
▫ Metastatic bone marrow replacement
16. Measurements in Anemia
• Hemoglobin = grams of hemoglobin per 100 mL
of whole blood (g/dL)
• Hematocrit = percent of a sample of whole
blood occupied by intact red blood cells
• RBC = millions of RBCs per mL of whole blood
• MCV = Mean corpuscular volume
• RDW = Red cell distribution width
• RDW= (Red cell volume ÷ mean cell volume) × 100
• Normal value is 11 -15%
• If elevated, suggests large variability in sizes of RBCs
17. 17
MCV
• MCV -Mean cell volume
• MCV is average size of RBC
• MCV = Hct x 10
RBC (millions)
• If 80-100 fL, normal range, RBCs considered
normocytic
• If < 80 fL are microcytic
• If > 100 fL are macrocytic
• Not reliable when have marked anisocytosis
fL= femtoliters
18. 18
RDW
• Most automated instruments now provide an RBC
Distribution Width (RDW)
• An index of RBC size variation
• May be used to quantitate the amount of
anisocytosis on peripheral blood smear
• Normal range is 11 % to 15% for both men and
women
• Anisocytosis: RBCs of unequal size. Reflected in
increased RDW (Red cell Distribution Width.)
19. Diagnosis of Anemia
Apart from before mentioned indices: the measurement of :
serum ferritin,
transferrin saturation,
serum soluble transferrin receptors, and
serum soluble transferrin receptors–ferritin index
are more accurate than in the diagnosis of iron
deficiency anaemia.
20. Beris P, Tobler A. Schweiz Rundsch Med Prax. 1997;86:1684.
Reprinted from Lambert JF, et al. In C Beaumont, P Beris, Y Beuzard, C Brugnara, eds. Disorders of iron
homeostasis, erythrocytes, erythropoiesis. Forum service editore, Genoa, Italy, 2006 page 73 figure 1, by
permission of European School of Haemotology.
Main Causes of Anaemia
Haemolysis
17.5%
Others
9%
Iron Deficiency
29%
Chronic Disease
27%
Acute
Bleeding
17.5%
21. Iron Deficiency Anemia
• Iron deficiency anemia (IDA) is the most
common form of anemia worldwide.
• In men and postmenopausal women the
commonest cause of IDA is blood loss from
lesions in the gastrointestinal tract,
making it a common cause of referral to
gastroenterologists.
• Causes of IDA relate either to
blood loss, or
iron mal-absorption
22. Iron deficiency Anemia
• The body needs iron to produce the Hb
necessary for RBC production.
• In general, most people need just 1 milligram
of iron daily.
• Menstruating women need double the
dose
23. Iron Deficiency
Successive Stages of Iron Deficiency
• Iron-deficient erythropoiesis,
▫ or functional iron deficiency
• Depletion of iron stores
• Iron-deficiency anaemia
Grosbois B, et al. Bull Acad Natl Med. 2005;189:1649.
25. Iron Deficiency—Iron loss
• In physiologic conditions
▫ Menstruation
• In pathologic conditions
▫ Surgery, delivery
▫ Haemoglobinuria,haemoptysis
▫ Gastrointestinal tract pathology
• In therapeutic procedures
▫ Phlebotomy
• In blood donation
26.
27. Iron Deficiency Anemia
• The CVS adaptations of chronic anemia can
worsen the condition of patients with underlying
cardiovascular disease and include:
▫ Tachycardia
▫ Increased cardiac output
▫ Vasodilation
• In the absence of adequate iron, small
erythrocytes with insufficient hemoglobin are
formed, giving rise to microcytic hypochromic
anemia.
28. Iron Deficiency
Clinical Manifestations
• Fatigue
• Decreased exercise tolerance
• Tachycardia
• Dermatologic manifestations
• Decreased intellectual performance
• Dysphagia
• Depression, increased incidence of infections
• Restless legs syndrome
Hoffman, ed. Hematology: Basic Principles and Practice, 4th ed. 2005.
Trost LB, et al. J Am Acad Dermatol. 2006;54:824.
29. Management
of IDA
• Treatment of iron deficiency anemia consists of correcting the
underlying etiology and replenishing iron stores.
• Oral ferrous iron salts are the most economical and
effective form
• Ferrous sulfate is the most commonly used iron salt
• Better absorption and lower morbidity have been claimed for
other iron salts
• Toxicity is generally proportional to the amount of iron
available for absorption
• Reserve parenteral iron for patients who are either
unable to absorb oral iron or who have increasing
anemia despite adequate doses of oral iron
• Reserve transfusion of packed RBCs for patients who
are experiencing significant acute bleeding or are in
danger of hypoxia and/or coronary insufficiency
31. IRON
Total body iron in adult is 2.5-5 g (average 3.5 g).
Men (50 mg/kg) > Women (38 mg/kg).
It is distributed into:
Haemoglobin (Hb) : 66%
Iron stores as ferritin and haemosiderin : 25%
Myoglobin (in muscles) : 3%
Parenchymal iron (in enzymes, etc.) : 6%
Iron forms the nucleus of the iron-porphyrin heme ring, which
together with globin chains forms hemoglobin.
In the absence of adequate iron, small erythrocytes with
insufficient hemoglobin are formed, giving rise to microcytic
hypochromic anemia.
32. Factors facilitating iron absorption
• 1. Acid: by favoring dissolution and
reduction of ferric iron.
• 2. Reducing substances:
• ascorbic acid,
• amino acids containing SH radical(cysteine and
methionine).
• These agents reduce ferric iron and form
absorbable complexes.
• 3. Meat: by increasing HCI secretion and
providing heme iron.
33. Factors impeding iron absorption
1. Alkalies (antacids) render iron insoluble, oppose
its reduction.
2. Phosphates (rich in egg yolk)
3. Phytates (in maize, wheat)
4. Tetracyclines
5. Presence of other foods in the stomach.
Above factors 2-4 impede by complexing with
iron.
In general, bioavailability of iron from cereal based
diets is low.
34. Uses
• The only clinical use of iron preparations is the
treatment or prevention of iron deficiency
anemia.
• Available as oral or parenteral preparations.
• If GI absorption of Iron is normal, oral and parenteral
agents are equipotent.
• Parenteral iron is usually preferred in patients with
advanced chronic kidney disease who are
undergoing hemodialysis and treatment with
erythropoietin.
35. ORAL IRON THERAPY
Oral iron
1. Ferrous sulfate:
Hydrated salt 20% iron,
Dried salt 32% iron 200 mg tab
2. Ferrous gluconate (12% iron) 300 mg Tab
3. Ferrous fumarate (33% iron) 200 mg Tab
4. Ferrous succinate (35% iron)
5. Ferric citrate is an oral iron that has shown
efficacy and gained FDA approval for treatment
of iron deficiency anemia in adults with CKD
and not on dialysis.
36. A/E
Dose-related
• Nausea, vomitting, epigastric discomfort,
abdominal cramps, bloating, colic
• Constipation, and diarrhea
• Staining of teeth, metallic taste
Can be minimized with dose reduction or by
taking it with or immediately after meals.
Black stools are common, patients must be
advised not to think of it as bloody stools.
37. PARENTERAL IRON THERAPY
Should be reserved for patients with
documented iron deficiency who are:
1. Unable to tolerate or absorb oral iron
2. Patients with extensive chronic blood loss
3. Patients who cannot be maintained with oral
iron alone.
4. Non-compliance to oral iron.
38. PARENTERAL IRON THERAPY
• Various conditions include:
• Different postgastrectomy conditions
• Previous small bowel resection
• IBD involving the proximal small bowel
• Malabsorption syndromes
• Advanced chronic renal disease including
hemodialysis and treatment with erythropoietin
39. PARENTERAL IRON THERAPY
1. Iron-Dextran
2. Iron-Sucrose Complex
3. Iron-Gluconate Complex
Iron dextran is given IV or as deep IM
injection.
While the later two are given through IV route
only. They are much less likely to cause
hypersensitivity reactions.
40. A/E
• Nausea and vomiting,
• Headache, light-headedness,
• Fever, arthralgias, back pain
• Flushing, urticaria,
• Bronchospasm, and, rarely, anaphylaxis and
death.
• Some are attributed to hypersensitivity reactions to
Dextran. A test dose therefore is always given.
• Even patients who received Iron-Dextran parenteral
therapy previously are at high risk.
41. A/E
Local
• Pain at site of i.m. injection,
• pigmentation of skin,
• sterile abscess- especially in old and debilitated patient.
Systemic
• Fever, headache, joint pains, flushing,
• palpitation, chest pain, dyspnoea,
• lymph node enlargement.
42. Poisonings
Seen in infants and children (> 60 mg/kg
iron)
Precipitates as
• vomiting, abdominal pain,hematemesis,
• diarrhoea, dehydration, acidosis,
• lethargy, cyanosis,convulsions;
• finally shock, cardiovascular collapse
• and death
Antidote: Desferrioxamine (chelating agent)
43. ACUTE IRON TOXICITY
• Acute Iron toxicity is seen almost exclusively in
young children who accidentally take the iron
tablets (like chocolates); 10 iron tablets can be
lethal in young children.
• Symptoms include: necrotizing gastroenteritis,
with vomiting, abdominal pain, and bloody
diarrhea followed by shock, lethargy, and
dyspnea which may be followed by severe
metabolic acidosis, coma, and death if
untreated.
• Whole bowel irrigation and Deferoxamine
should be initiated with supportive therapy for
GI bleeding, metabolic acidosis and shock.
44. CHRONIC IRON TOXICITY
Iron overload or hemochromatosis
Excess iron is deposited in the heart, liver, pancreas,
and other organs. It can lead to organ failure and death.
It is most common in patients with inherited
hemochromatosis, a disorder characterized by excessive
iron absorption, and in patients who receive many red
cell transfusions over a long period of time (eg, patients
with thalassemia major-hemolytic anemia-
hypochromic type).
In the absence of anemia, it is most efficiently treated by
intermittent phlebotomy removing one unit of blood
every week or so until all of the excess iron is removed.
Parenteral deferoxamine is much less efficient as well as
more complicated while deferasirox (oral iron chelator )
is much more convenient.
45. BLOOD TRANSFUSION
There is no universally accepted threshold for transfusing
packed red blood cells in patients with iron deficiency anemia.
Guidelines often specify certain hemoglobin values as
indications to transfuse, but the patient’s clinical condition
and symptoms are an essential part of deciding whether to
transfuse.
Transfusion is recommended in pregnant women with
hemoglobin levels of less than 6 g per dL because of potentially
abnormal fetal oxygenation resulting in nonreassuring fetal
heart tracings, low amniotic fluid volumes, fetal cerebral
vasodilation, and fetal death.
If transfusion is performed, two units of packed red blood cells
should be given, then the clinical situation should be
reassessed to guide further treatment.
