Disorders of RBCs

Blood

• Total blood vol.: 5-6 L

• 45% Erythrocytes

• 55% Plasma

• <1% Platelets and Leuokocytes

• 4 blood types and Rh factors

Functions of RBC

• Gas Exchange

• Buffer blood pH

• Anucleate

80-120 day lifespan

Hemoglobin

• 1 Hem carry 4 O2’s

• 4 Polypeptide chains

  • 2 globin and 2 heme per chain

• Iron in Hem

Erythropoiesis

• Occurs in bone marrow

• pluripotent stem cells → erythrocytes

  • Erythropoietin made in kidneys

• Heme# increases → nucleus decreases in size/eliminated

Triggered

• by decreased O2 reaching tissues

• Decrease factors

  • Anemia

  • Hypoxia

RBC Destruction

• after 120 days

  • function/metabolic activity diminished

  • cell wall fragile

• broken down my macrophages in spleen

• iron and amino acids recycled

Oxygen Transport

Right Shift

Left Shift

Anemia

• lower # of RBC or hemoglobin or both

Anemia Classifications

“-cytic” - size

• Macro

• Normo

• Micro

“chromic” - heme content/concentration

• Hyper

• Normo

• Hypo

Anemia Clinical Manifestations

• Classic: Fatigue, weakness, SoB, and pallor

• Mild to moderate: everything + generalized weakness, loss of stamina, tachycardia and exertional SoB to compensate

• Moderate to severe: everything + orthostatic & generalized hypotension, vasoconstriction, tachypnea

Iron Deficiency Anemia

• dietary deficiency in iron, loss of iron thru bleeding, or increased iron demand

• lack of iron affects heme synthesis

• microcytic, hypochromic anemia

Iron Deficiency Anemia Clinical Manifestations, Diagnostics & Treatment

Manifestations

• fatigue, pallor, indented nails, red tongue, pica

Tests

• low Hgb & Hct

• low serum iron and ferritin

• low MVC, MCH

Treatment

• iron supplement

• change in diet

B12 Deficiency Anemia

• B12 need for DNA synthesis, RBC production, lipid regulation in nerv. system

• Pernicious anemia can cause B12 deficiency

• Macrocytic, normochromic

B12 Deficiency Manifestations, Diagnostics, and Treatment

Manifestations

• moderate to severe anemia symptoms

• nervous system demyelination

• Neuropsychiatric changes

Tests

• High MCV

• lower serum B12 level

Treatment

• B12 replacement long term

Folic Acid Defiency

• needed for DNA synthesis and RBC production

• from leafy vegies (most nutrients lost in cooking)

• poor dietary intake, alcohol, malabsorption, increased demand

• Macrocytic, Normochromic

Folic Acid Deficiency Anemia Manifestations and Treatment

Manifestations

• same to B12 anemia except neurological manifestations

• moderate to severe anemia symptoms

• spina bifida development in fetus

Treatment

• vitamin supplement

• change diet / lifestyle

• address underlying causes

Aplastic Anemia

• affects all blood cells from pluripotent stem cells

• failure of bone marrow replacing destroyed RBC

• caused by exposure to radiation, chemo, and toxins, suppressing bone marrow

Aplastic Anemia Manifestations, Diagnostics, and Treatment

Manifestations

• low WBC’s → infection

• low platelets → bleeding, clotting abnorm

• low RBC’s → anemia symptoms

Tests

• biopsy

• lab values showing pancytopenia

Treatment

• depends

• potential transplant

• antibiotics

• stem cell transplant

Chronic Inflammation, Infection, Cancer Anemias

• mild to moderate

• decreased erythrocyte lifespan

• ineffective bone marrow