DISORDERS OF RED BLOOD CELLS

ANEMIA

reduction in the oxygen-carrying capacity of the blood, is usually associated with a decreased number of circulating RBCs or an abnormality in the hemoglobin (Hb) contained within the RBCs

ANEMIA

not a disease but rather a symptom complex

IRON DEFICIENCY ANEMIA

a microcytic anemia that can be caused by excessive blood loss, poor iron intake, poor iron absorption, or increased demand for iron

FOLATE

is needed for enzymatic reactions required for the synthesis of purines and pyrimidines of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) and thus for the synthesis of proteins.

RISK FACTORS FOR FOLATE DEFICIENCY

• poor diet

• Alcoholism

• History of malabsorption disorders

• Pregnancy (3rd trimester)

PERNICIOUS ANEMIA

Most Pts with this disease has chronic atrophic gastritis with decreased intrinsic factor and hydrochloric acid secretion

PERNICIOUS ANEMIA

Antibodies against parietal cells and intrinsic factor also are present in the

sera of most patients

PERNICIOUS ANEMIA

This finding strongly suggests that the disease is of autoimmune origin

LONG-STANDING PERNICIOUS ANEMIA

associated with increased risk for development of gastric carcinoma

HEMOLYTIC ANEMIA

consist of sickle cell anemia, thalassemia, and glucose-6-phosphate dehydrogenase (G6PD) deficiency

HEMOLYTIC ANEMIA

They are commonly caused by immune attack, extrinsic factors, disorders of

the RBC membrane, enzymopathies, and hemoglobinopathies

SICKLE CELL HEMOGLOBIN

result of substitution of a single amino acid—valine for glutamic acid—at the sixth residue of the β chain.

Sickle cell disorders

distinguished by the number of globin genes affected

SICKLE CELL TRAIT

heterozygous state in which the affected person carries one gene for HbS

SICKLE CELL ANEMIA

It is the homozygous state

In patients w/ sickle cell anemia

more than 80% of the Hb is HbS

Distortion of the RBC into a sickled shape

results from deoxygenation or decreased blood pH, causing partial crystallization of HbS, polymerization, and realignment of the defective Hb molecule

BIRTH TO 20 YEARS OF AGE

painful events, stroke, acute chest syndrome (fever, chest pain, wheezing, cough, and hypoxia), acute anemia, and infection

FROM 20 to 40 YEARS OF AGE

osteonecrosis of hip and shoulder joints, leg ulcers, priapism, liver disease, and gallstones

OLDER THAN 40 YEARS OF AGE

pulmonary hypertension, nephropathy, proliferative retinopathy, and cardiac enlargement, heart murmurs, and sudden death from arrhythmias

GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY (G6PD)

enzyme that enables the RBC to convert carbohydrates into energy via the hexose monophosphate shunt pathway

APLASTIC ANEMIA

occurs when the bone marrow is unable to produce adequate numbers of RBCs, white blood cells (WBCs), and platelets

In children with microcytic anemia

iron supplements (ferrous sulfate, 2–6 mg/kg/day)

In patients who have undergone a gastrectomy

iron supplements (ferrous sulfate, ferrous fumarate, or ferrous gluconate)

In cases in which blood loss is uncontrollable

iron cannot be absorbed, or iron is not tolerated

Parenteral iron

given by their intravenous (IV) or intramuscular injection

In men

management often involves treatment of the underlying cause (e.g., peptic ulcer disease, GI malignancy)

Folate deficiency

is managed by administering folic acid supplements and by increasing the

intake of green, leafy vegetables and citrus fruits

In the case of poor intestinal absorption,

replacement therapy with folic acid may be lifelong

Cyanocobalamin injections

used for patients with pernicious anemia

Cyanocobalamin injections

given daily for the first week and then are tapered eventually to once a month, as needed

Penicillin prophylaxis

used for at least the first 5 years of life

Patients older than 16 years of age

are much less likely to have successful grafts