Anemia is defined as a reduction in red blood cells or hemoglobin. It can be caused by blood loss, decreased red blood cell production, or increased red blood cell destruction. Evaluation of an anemic patient involves obtaining a medical history and physical exam to determine the cause, such as bleeding, bone marrow suppression, or nutritional deficiencies. Initial lab tests include a complete blood count with red blood cell indices to classify the anemia and guide further testing.

2. DEFINITIONS
Anemia- reduction in one or more of the major red blood
cell (RBC) measurements obtained as a part of the
complete blood count (CBC): hemoglobin concentration,
hematocrit (HCT), or RBC count.
- Hemoglobin: - the major oxygen-carrying molecule in
whole blood
- grams of hemoglobin per 100 mL of
whole blood (g/dL) or per liter of blood
(g/L)

3. -Hematocrit: -packed cell volume, is the packed spun
volume of blood that consists of intact RBCs,
expressed as a percentage.
- can be measured directly following
centrifugation of a blood sample or
calculated (HCT = [RBC x MCV]/10)
-RBC count : - number of RBCs contained in a specified
volume of whole blood,
- expressed as millions of cells per microL of
whole blood.

4. One set of normal ranges for hemoglobin, HCT, and RBC
count

5. Other normal ranges have been proposed:
• Other authors have proposed different lower limits of normal
for the hemoglobin level, ranging from 13.0 to 14.2 g/dL for
men and 11.6 to 12.3 g/dL for women
• World Health Organization (WHO) criteria for anemia in men
and women are <13 and <12 g/dL, respectively .
-meant to be used within the context of international nutrition
studies, and were not initially designed to serve as "gold
standards" for the diagnosis of anemia
• The revised WHO/National Cancer Institute's criteria for
anemia in men and women are <14 and <12 g/dL,
respectively.
-These values were meant to be used for evaluation of anemia
as a complication of chemotherapy in patients with malignancy

6. Red blood cell indices
• describe the size, shape, and hemoglobin content of RBCs
a) Mean corpuscular volume (MCV)
-average volume (size) of the patient's RBCs
- N : 80-100 fL
- (MCV in femtoliters [fL] = 10 x HCT [in percent] ÷ RBC [in
millions/microL])
b) Mean corpuscular hemoglobin (MCH)
-average hemoglobin content in a RBC
- N: 27.5-33.2 picograms
- (MCH in picograms [pg]/cell = hemoglobin [in g/dL] x 10 ÷
RBC [in millions/microL])

7. c) Mean corpuscular hemoglobin concentration (MCHC)
-average hemoglobin concentration per RBC
- N: 32-36 dL
-mean normal value is approximately 34 grams of
hemoglobin per dL of RBCs (340 g/L of RBCs)
- (MCHC in grams [g]/dL = hemoglobin [in g/dL] X 100 ÷
HCT [in percent])
d) Red cell distribution width (RDW)
- measure of the variation in RBC size, which is reflected
in the degree of anisocytosis on the peripheral blood
smear
- (RDW = [standard deviation/MCV] x 100)

11. ERYTHROPOIESIS
HSC: HEMATOPOIETIC STEM CELL, CFU-GEMM: COLONY FORMING UNIT GRANULOCYTE
ERYTHROCYTE MONOCYTE MEGAKARYOCYTE, BFU-E:BURST FORMING UNIT ERYTHROID, CFU-E:
COLONY FORMING UNIT ERYTHROID

12. Depend on the degree of anemia and rate at which it
has evolved
•Decreased oxygen delivery to tissues
- Exertional dyspnea, dyspnea at rest, fatigue,
lethargy, confusion and life-threatening
complications such as congestive failure, angina,
arrhythmia, and/or myocardial infarction.
•Hypovolemia (acute bleeding)
- Postural dizziness, lethargy, syncope,
hypotension, shock, and death.
Signs and Symptoms Related to Anemia

13. CAUSES OF ANEMIA
There are two general approaches one can use to
help identify the cause of anemia.
• A kinetic approach, addressing the mechanism(s)
responsible for the fall in hemoglobin concentration
• A morphologic approach categorizing anemias via
alterations in red blood cell (RBC) size (ie, mean
corpuscular volume) and the reticulocyte response

14. THREE INDEPENDENT MECHANISMS
a) Decreased RBC production
-Lack of nutrients, such as vitamin B12 and iron
-Bone marrow disorders (eg, aplastic anemia, pure RBC
aplasia, bone marrow infiltration)
-Bone marrow suppression (eg, drugs, chemotherapy,
irradiation)
-Low levels of trophic hormones, which stimulate RBC
production, such as erythropoietin (EPO; eg, chronic renal
failure), thyroid hormone (eg, hypothyroidism), and
androgens (eg, hypogonadism)
Kinetic Approach

15. - Anemia of chronic disease/ inflammation secondary to
reduced availability of iron, relative reduction in EPO and
mild reduction in RBC life span
- A markedly low reticulocyte count (eg, <10,000/microL)
is suggestive of pure red cell aplasia (PRCA), or, if the
other cell counts are similarly low, aplastic anemia
b) Increased destruction of circulating RBCs
-A RBC life span below 100 days is the operational
definition of hemolysis
- EXTRAVASCULAR & INTRAVASCULAR causes

17. c) Blood loss
• Obvious bleeding (eg, trauma, melena, hematemesis,
severe menometrorrhagia)
• Occult bleeding (eg, slowly bleeding ulcer or carcinoma)
• Induced bleeding (eg, repeated diagnostic testing ,
hemodialysis losses, excessive blood donation)
• Underappreciated menstrual blood loss

18. • The normal RBC has a volume of 80 to 96 femtoliters
(fL, 10-15 liter) and a diameter of approximately 7 to 8
microns, equal to that of the nucleus of a small
lymphocyte
1) Microcytic Hypochromic anemia : low red cell
indices
2) Macrocytic Normochromic anemia : MCV MCH
MCHC (N)
3) Normocytic anemia: Normal red cell indices
- can be narrowed by examination of the blood smear
to assess if patient could be placed in the above
categories or by use of the kinetic approach
Morphologic Approach

20. EVALUATION OF THE ANEMIC PATIENT
Initial approach
-History, physical examination, and simple laboratory
testing are all useful in evaluating the anemic patient
-The workup should be directed towards answering the
following questions:
• Is the patient bleeding (now or in the past)?
• Is there evidence for increased red blood cell (RBC)
destruction (either intravascular or extravascular)?
• Is the bone marrow suppressed? If so, why?
• Is the patient iron deficient? If so, why?
• Is the patient deficient in folate or vitamin B12? If so,
why?

21. History
There are a number of important components to the history
in the setting of anemia:
●Is there a recent history of loss of appetite, weight loss,
fever, and/or night sweats that might indicate the
presence of infection or malignancy?
●Is there a history of, or symptoms related to, a medical
condition that is known to result in anemia ?
eg: -black / tarry stools in a patient with ulcer-type pain,
-significant blood loss from other sites
- rheumatoid arthritis
-renal failure

22. ●Is the anemia of recent origin, subacute, or lifelong?
- Recent anemia is almost always an acquired disorder
- lifelong anemia, particularly if accompanied by a positive
family history, is likely to be inherited
eg: -hemoglobinopathies
-thalassemia
- hereditary spherocytosis

23. Physical examination
-to find signs of organ or multisystem involvement and to assess
the severity of the patient's condition
•Vital signs: tachycardia, hypotension, fever
•Pallor
•Jaundice
•Lymphadenopathy, hepatosplenomegaly, and
bone tenderness
•Petechiae, ecchymoses, and other signs of
bleeding disorder
•Signs of organ or multisystem involvement (e.g.
heart failure, CNS)
•Signs of nutritional deficiency

24. LABORATORY EVALUATION