Transcript Anemia - doc meg's hideout

Anemia
Dr. Meg-angela Christi M. Amores
What is Hematopoeisis?
• It is the process by which the formed
elements of the blood are produced
• Erythropoeisis: production of erythrocytes
(red blood cells)
• Regulatory hormone: EPO (erythropoeitin)
– kidney
Erythropoeisis
• Critical elements:
– EPO production
– iron availability
– the proliferative capacity of the bone marrow
– effective maturation of red cell precursors
Anemia
• Often recognized by abnormal screening tests
• Less commonly presents signs and symptoms
unless advanced
• Acute anemia – due to blood loss or hemolysis
– If acute blood loss, hypovolemia results
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Hypotension is the issue, not anemia
10 – 15% blood loss- signs of vascular instability
>30% - postural hypotension, tachycardia
>40% - hypovolemic shock (confusion, dyspnea,
diaphoresis, hypotension, tachycardia)
Anemia
• Acute anemia – due to blood loss or hemolysis
– Acute hemolysis
• Symptoms: fatigue, loss of stamina, breathlessness,
and tachycardia (particularly with physical exertion)
• Most often only occurs when advanced (hgb <7 mg/dL)
Approach to patient
• History:
– Nutritional (food, drugs, alcohol)
– Family history
– G6PD deficiency
• PE:
– Findings of infection
– blood in the stool, lymphadenopathy,
splenomegaly, or petechiae
– forceful heartbeat, strong peripheral pulses, and a
systolic "flow" murmur
Pallor
• skin and mucous membranes may be pale if
the hemoglobin is <80–100 g/L (8–10 g/dL)
• If palmar creases are lighter in color than the
surrounding skin when the hand is
hyperextended, the hemoglobin level is
usually <80 g/L (8 g/dL)
Laboratory Evaluation
Normal Hgb and Hct levels
CBC
• Components of CBC help in the classification
of anemia:
– Microcytosis - reflected by a lower than normal
MCV (<80)
– Macrocytosis - high values (>100) of MCV
– MCH and MCHC reflect defects in hemoglobin
synthesis - hypochromia
Peripheral blood smear
• provides important information about defects
in red cell production
• the blood smear also reveals variations in cell
size (anisocytosis) and shape (poikilocytosis)
Reticulocyte count
• key to the initial classification of anemia
• Normally, the reticulocyte count ranges from
1–2% and reflects the daily replacement of
0.8–1.0% of the circulating red cell population
• reticulocyte count provides a reliable measure
of red cell production
• In the face of established anemia, a
reticulocyte response less than two to three
times normal indicates an inadequate marrow
response.
Tests of Iron Supply and storage
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serum iron
TIBC
percent transferrin saturation
serum ferritin is used to evaluate total-body
iron stores
Bone Marrow examination
• Indications:
– patients with
hypoproliferative anemia
and normal iron status
– can diagnose primary
marrow disorders such
as myelofibrosis, a red
cell maturation defect,
or an infiltrative disease
Functional Classification
1. marrow production defects (hypoproliferation)
2. red cell maturation defects (ineffective
erythropoiesis )
3. decreased red cell survival (blood loss
/hemolysis)
Hypoproliferative Anemia
• 75% of all anemia
• reflects absolute or relative marrow failure
• Majority are due to mild to moderate iron
deficiency or inflammation
• can result from marrow damage, iron
deficiency, or inadequate EPO stimulation
• normocytic, normochromic red cells
• Key diagnostic tool: IRON studies
Hypoproliferative Anemia
• anemia of acute or chronic inflammation
– serum iron (low), TIBC (normal or low), percent
transferrin saturation (low), and serum ferritin
(normal or high)
• mild to moderate iron deficiency
– (low serum iron, high TIBC, low percent transferrin
saturation, low serum ferritin)
Maturation disorders
• anemia with an inappropriately low
reticulocyte production index, macro- or
microcytosis on smear, and abnormal red cell
indices
• ineffective erythropoiesis that results from the
destruction within the marrow
• vitamin B12 or folic acid deficiency, drug
damage, or myelodysplasia
Blood Loss / Hemolytic Anemia
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Red blood cell indices >2.5x the normal
stimulated erythropoiesis
typically normocytic or slightly macrocytic
Hemolysis – least common form of anemia
– present in different ways
– paroxysmal nocturnal hemoglobinuria
– Hemoglobinopathies
– hereditary spherocytosis
Treatment
• Severe anemia: red cell transfusions
• acute or gradual onset: determined by the
documented cause(s) of the anemia
• important to evaluate the patient's iron status
fully
• Chronic kidney disease: Recombinant EPO