Reviewer #11 Flashcards
Mature RBC are called
Erythrocytes
Carry oxygen to cells
Hemoglobin
Abnormally low number of circulating RBCs, low haemoglobin concentration, or both.
Anemia
Usual cause of anaemia
Decreased numbers of circulating RBC
A nutritional anaemia, is most common type of anaemia
Iron deficiency anemia
When anaemia results from acute or chronic bleeding its classified as
Blood loss anemia
What are the compensatory mechanisms that are activated to maintain the cardiac output
The heart rate increases and Peripheral blood vessels constrict.
If hemorrhage continues, compensatory mechanisms become less effective, increasing the risk of
Shock and Circulatory failure
RBCs are of normal size and shape
Normocytic
RBCs are of small size and shape
Microcytic
RBCs are of normal color
Normochromic
RBCs are of pale
Hypochromic
Key difference in acute blood loss and chronic blood loss anemia
If iron is sufficient the hemoglobin levels may return to normal within 3 to 4 weeks in acute blood loss however in chronic it depletes the rbc storage
Normal red blood cell development
Erythropoesis
A key nutrient necessary for haemoglobin synthesis
Iron
Vitamins that play a key role in RBC development
Vitamin B12 (Cobalamin) and B9 (Folate)
Vitamin B12 and folic acid anaemias are sometimes called
Megaloblastic anemia (due to enlarged nucleated RBCs called megaloblasts)
Malformed RBCs
Poikilocytosis
The usual cause of iron deficiency anaemia in adults
Excessive iron loss due to chronic bleeding
The most common cause in adult females
Menstrual blood loss
Failure to absorb dietary vitamin B12 is called
Pernicious anemia
Pernicious anemia develops due to a lack of
Intrinsic factor (substance
secreted by the gastric mucosa)
Pathognomonic sign of pernicious anemia
Beefy red tongue
Altered sensations, such as numbness or tingling) in the extremities
Paraesthesia
Vitamin B12 is important for
Neurological function
Characterized by fragile, megaloblastic (large and immature) cells
Folic Acid Deficiency Anemia
Alcoholics are especially at risk because
Alcohol suppresses folate metabolism
Difference between B12 and B9 anemia
No neurological symptoms occur with folic acid deficiency anaemia
Are characterised by premature destruction (lysis) of RBCs
Hemolytic anemia
Causes that arise from disorders within the RBC itself
Intrinsic causes
Cause that originates outside the RBC
Extrinsic cause
Intrinsic disorders include
Cell membrane defects
A hereditary, chronic haemolytic anaemia. It is characterised by of sickling
Sickle cell anemia (RBC becomes crescent shaped)
The disorder is transmitted as an
Autosomal recessive genetic defect
Sickle cell anaemia can significantly shorten lifespan, with most deaths occurring due to
Infection
Marked by pooling of large amounts of blood in the liver and spleen
Sequestration crisis
Inherited disorders of haemoglobin synthesis in which either the alpha or beta chains of the haemoglobin molecule are missing or defective.
Thalassemia
Mediterranean descent are more
likely to have beta-defect thalassaemias called
Cooley’s anemia
One defective beta-chain forming gene may be present
Beta-thalassemia minor
Both gene may be defective
Beta-thalassemia major
One, two, three or all four may be defective
Alpha-thalassemia major
People with thalassemia minor are often
Asymptomatic
Results from haemolysis due to factors the RBC
Acquired Hemolytic Anemia
Caused by a hereditary defect in RBC metabolism. It is relatively common in people of African and Mediterranean descent. The defective gene is located on the X chromosome and therefore affects more males than females.
Glucose-6-phosphate dehydro (G6PD) anaemia
The bone marrow fails to produce all three types of blood cells
Aplastic Anemia
A condition where the number of red blood cells, white blood cells, and platelets in the blood is lower than normal.
Pancytopenia
A rare aplastic anaemia caused by defects of DNA repair
Fanconi anemia
The underlying cause of about 50% of acquired
aplastic anaemia is unknown
Idiopathic aplastic anemia
The priority of care in treating anaemia
Ensuring adequate tissue oxygenation
Done to determine blood cell counts, haemoglobin, haematocrit and red blood cell indices. The severity of the anaemia and the shape, volume and iron content of the RBCs can help determine the cause of anaemia.
Full Blood Count (FBC)
Performed to detect iron deficiency anaemia. A low serum iron concentration and elevated total iron-binding capacity are indicative of iron deficiency anaemia
Iron levels and total iron-binding capacity
Low due to depletion of the total iron reserves available for haemoglobin synthesis. Ferritin is an iron-storage protein produced by the liver, spleen and bone marrow. Ferritin mobilises stored iron when metabolic needs are higher than dietary intake.
Serum ferritin
A screening test to evaluate haemolytic
anaemia and detect HbS
Sickle cell test
Separates normal hemoglobin from abnormal forms. It is used to evaluate haemolytic anemia, diagnose thalassemia and differentiate sickle cell trait from sickle cell disease
Haemoglobin electrophoresis
Measures vitamin B12 absorption before and after intrinsic factor administration to differentiate between pernicious anaemia and intestinal malabsorption of the vitamin. A 24 hour urine sample is collected following
administration of radioactive vitamin B12. Lower than normal levels of the tagged B12 when intrinsic factor is given concurrently indicate malabsorption rather than pernicious
anaemia
Schilling test
Done to diagnose aplastic anaemia. In aplastic anaemia, normal marrow elements are significantly decreased as they are replaced by fat cell
Bone marrow examination
A major concern when iron dextran is given intravenously.
Anaphylaxis
Method of injection is recommended for the intramuscular administration of iron because it decreases irritation and staining and assists
with sealing the medication in muscle tissue
Z track method
A group of blood disorders characterised by abnormal-appearing bone marrow and cytopenia (low numbers of circulating blood cells).
Myelodysplastic syndrome
Anaemia that does not respond to treatment
Refractory anemia
An excess of red blood cells characterised by a hematocrit higher than 55%.
Polycythaemia, or erythrocytosis
The two main types of polycythaemia are
Primary and Secondary
A third type of polycythaemia which results
from a fluid volume deficit, not excess RBCs
Relative Polycythemia
A neoplastic stem cell disorder characterised by overproduction of RBCs and, to a lesser extent, white blood cells and platelets.
Primary polycythemia
Primary polycythemia is classified as a
Myeloproliferative disorder
Increased numbers of RBCs in response to excess erythropoietin secretion or prolonged hypoxia. Secondary polycythaemia is the most common form of polycythaemia.
Secondary polycythaemia, or erythrocytosis
Difference of primary and secondary polycythemia
Spleenomegaly does not develop in secondary
A group of chronic malignant disorders of white blood cells and white blood cell precursors.
Leukemia
Stem cells that have developed to the stage where they are committed to forming a particular kind of new blood cell.
Precursor cells
All leukaemias start in the
Bone marrow
In leukaemia, the usual ratio of red to white blood cells is
Reversed
Characterised by uncontrolled proliferation of myeloblasts (the precursors of granulocytes) and hyperplasia of the bone marrow and spleen
Acute myeloid leukemia
Characterised by abnormal proliferation of all bone marrow elements
Chronic Myeloid Leukemia
CML is usually associated with a chromosome abnormality called the
Philadelphia chromosome
Characterised by proliferation and accumulation of small, abnormal, mature lymphocytes in the bone marrow, peripheral blood and body tissues.
Chronic lymphocytic leukaemia
Treatment of choice for some types of leukaemia
Bone marrow transplant
Malignancies of lymphoid tissue. They are
characterised by the proliferation of lymphocytes, histiocytes (resident monocytes or macrophages) and their precursors or
derivatives
Lymphomas
A rare lymphatic cancer, occurring most often in people between the ages of 15 and 35.
Hodgkins disease
A diverse group of lymphoid tissue
malignancies that do not contain Reed Sternberg cells.
Non-Hodgkin’s lymphomas
A malignancy in which plasma cells multiply uncontrollably and infiltrate the bone marrow, lymph nodes, spleen and other tissues
Multiple Myeloma
A platelet count of less than 150 × 109/L
of blood. It can lead to abnormal bleeding
Thrombocytopenia
The most common drug-induced thrombocytopenia
Heparin
The two types of primary thrombocytopenia are
Immune thrombocytopenic purpura and thrombotic thrombocytopenic purpura
Also known as idiopathic thrombocytopenic purpura, is an autoimmune disorder in which platelet destruction is accelerated.
Immune thrombocytopenic purpura (ITP)
A rare disorder in which thrombi occlude arterioles and capillaries of the microcirculation. Many organs are affected, including the heart, kidneys and brain
Thrombotic thrombocytopenic purpura (TTP)
Develops as a result of an abnormal response to heparin therapy
Heparin-induced thrombocytopenia (HIT)
A protein that occurs naturally in human tissues and inflammatory cells.
Heparin
A group of hereditary clotting factor disorders that lead to persistent and sometimes severe bleeding. Although often considered a disease of children, haemophilia may be diagnosed in adults
Hemophilia
A disruption of haemostasis characterised by widespread intravascular clotting and bleeding. It may be acute and life threatening or
relatively mild. DIC is a clinical syndrome that develops as a complication of a wide variety of other disorders
Disseminated intravascular coagulation
The most common cause of DIC
Sepsis
Test for sickle cell anemia
Sickledex
Caused by loss of blood volume, resulting in fewer blood cells
Hypovolemic anemia
Is the pigmented, iron containing portion of hemoglobin
Heme
Confirmation test for hypovolemic anemia is
CBC
Erythrocytes in the process of maturation
Reticulocytes
Crack at the corners of the mouth
Cheilosis
Erythrocyte destruction is manifested by
Jaundice due to Hyperbilirubinemia
Prolonged erection
Priapism
A predictor of Acute Chest Syndrome
Increase in secretory phospholipase
In sickle cell anemia the treatment is
Supportive rather than Curative
Confirmatory test for Pernicious anemia
Schilling test
