Hematologic Problems

Question 0

Thalassemia

Answer 0

Occurs when there is a defect in gene that helps control production of one of these proteins (alpha globin and beta globin)
Thalassemia both destroys RBCs and produces defective RBCs.
This disorder results in excessive destruction of red blood cells and anemia.

Question 1

Anemia

Answer 1

RBC destruction( hemolysis - sickle cell disease, medications, incompatible blood, trauma), blood loss, due to hemorrhage -acute or chronic,  decreased RBC production due to deficient nutrients ( iron, vit b12, frolic acid)
-decreased erythropoietin)

Question 2

Iron deficiency anemia

Answer 2

Common hematologist disorder

Causes -inadequate dietary intake, malabsorption, hemolysis

Question 3

Megoblastic anemias

Answer 3

Caused by impaired DNA synthesis
RBCs easily destroyed due to fragile cell membrane
B12 deficiency, frolic acid deficiency
Most common in Northern European & African Americans

Question 4

Hemolytic Anemia

Answer 4

History of ABO or Rh incompatibility or drug exposure. Increased bilirubin, jaundice, positive direct anti globulin. Red cells are normocytic and normochromic.
Destruction of RBCs
- intrinsic
Usually hereditary
Sickle cell, G6PD deficiency, spherocytosis
- extrinsic
Trapping of cells in the liver or spleen
Antibody- mediated destruction
Toxins
Mechanical injury ( prosthetic heart valves)

Question 5

Acquired hemolytic anemia

Answer 5

Physical ( hemodialysis, heart valves)
Immune reaction ( incompatible blood, lupus, leukemia, drugs, IGG covering RBC)
Infectious agents and toxins ( parasites, clostridium per fringes bacteria, arsenic, lead, copper, snake venom)

Question 6

Hallmarks of sickle cell disease
Vaso- occlusive crisis
- sickles cells cannot pass through capillaries

Answer 6

Hemolysis- sickled cells hemolyzed by the spleen.

Question 7

Polycythemia (red cells are present in excess)

Answer 7

-increased blood viscosity,
Increased blood volume (hypervolemia)
-congestion of organs and tissues.
Hypertension

Question 8

Polycythemia Vera

Answer 8

A chronic myeloproferative disorder caused by a chromosomal mutation.

• involves RBCs, WBCs and platelets
• splenomegaly and hepatomegaly are common.

Question 9

Secondary polycythemia

Answer 9

Hypoxia- (Deficiency in amount of oxygen reaching the tissues) driven
Physiologic response (stimulates erythropoietin)
- high altitude
Pulmonary disease
Cardiovascular disease
Tissue hypoxia

Hypoxia independent-!tumors

Question 10

Thrombocytopenia ( platelet disorder)- common cause of generalized bleeding

Answer 10

Platelet counts below 100,000, when it drops to 75,000 -50,000 start thinking about transfusion.
Causes: bone marrow problem: decreased number produced
-increased storage in spleen
Abnormal destruction by antibody (I.e drug induced) or consumption as seen in DIC

Question 11

Clinical manifestations of thrombocytopenia

Answer 11

Bleeding time is prolonged
Petechiae- flat, pinpoint, no blanching red or purple spots
- capillary, hemorrhage within skin of mucos membrane
Purpura- petechiae in groups or patches, may be itchy
Hematoma- a bruise that is raised
Hemarthrosis- bleeding into joint results in swelling and pain

Question 12

Causes of thrombocytopenia

Answer 12

Herbs, food, drugs
- offending agents binds to the surface of the platelet
- antibodies then attack the platelets
Autoimmune diseases
Splenomegaly
Bone marrow suppression or failure
Platelet destruction can develop because of immunologic causes ( HIV infection, drugs, connective tissue or lymphoproliferative disorders, blood transfusion) or no immunologic causes (sepsis, acute resp. Distress syndrome)

Question 13

Hemophilia (coagulation disorder)

Answer 13

2 main types a& b
A classic (85%)
- factor vIII deficiency; 1/ 10,000 males.
B
- deficiency of factor IX; 1/ 50,000
X- linked recessive disorder
Affects males predominately, females are usually a asymptomatic carriers
Hereditary disorder

Question 14

Clinical manifestations of hemophilia

Answer 14

A&b have similar symptoms
If severe diseas, have < 1% normal clotting factors with spontaneous bleeding
If moderate level, 1-4% normal clotting factors with bleeding after trauma
If mild, have 2-5% normal levels with bleeding only after sever trauma.

Question 15

Clinical manifestations of hemophilia cont

Answer 15

Spontaneous bleeding in first year is rare; by 3-4 years 90% of children have persistent bleeding after minor trauma.
Bleeding in soft tissues, GI tract, joints
- hemarthrosis is hallmark symptom (elbow, knee or ankle joints most commonly affected)
- bleeding into joint causes inflammation of synovium with pain and swelling.
-with recurrent joint bleeding may have fibrosis and contractures, can become major disability.
(Joints begin to look like an older persons joints who have had arthritis for a long time)

Question 16

Disseminated intravascular clotting (DIC)

Answer 16

Acquired syndrome (complication) in which clotting and bleeding occur simultaneously. 
Paradox: widespread clotting in small vessels lead to blood vessel occlusion and tissue ischemia and consumption of clotting factors and platelets which may lead to hemorrhage.
Unbalanced sea- saw... Serious clotting takes place, then bleeding...

Question 17

Predisposing conditions that can initiate DIC

Answer 17

Acute:
Shock: hemorrhagic, cardio genie, anaphylactic
-septicemia
- hemolysis: d/ t mismatched blood transfusions or acute hemolysis from infections
-obstetric: abruptio placentae, amniotic fluid embolism, septic abortion
-cancers
-crush- tissue injury
(Burns, trauma, heatstroke, snakebites
-multiple blood transfusions

Question 18

DIC

Answer 18

Stimulus activates clotting cascade
-intravascular thrombin is produced
Catalyzes fib roger to fibrin and plt aggregation
Widespread fibrin and platelet deposition in capillaries and arterioles. ( causing thrombosis)
This excessive clotting activates fibrinolytic system
, breaks down clot to form fibrin split produces or fibrin degradation products (FDP)
-FDP is anticoagulant and inhibit clotting.
- accumulation of FDP and consumption of clotting actors results in inability to form stable clots.
Thus risk hemorrhage.

Question 19

DIC

Answer 19

An Acquired bleeding syndrome associated with a number of etiologic factors, including trauma, malignancy, burns, shock and abruptio placentae. DIC is characterized by widespread clot formation in small vessels. Clotting factors and platelets are consumed, leaving the patient with deficient resources for appropriate clot formation.

Question 20

Hodgkin’s disease vs non-Hodgkin’s disease

Answer 20

Hodgkin’s disease has presence of reed- stern berg cells and is more treatable, where non- Hodgkin’s does not.

Question 21

Multiple myeloma

Answer 21

Cancer of plasma cells
Seen more in males, after age 65.
Presence of Bence-jones protein -diagnostic tool
Leads to bone destruction, marrow is effected,Swiss cheese look to bones.

Question 22

Red blood cell development

Answer 22

From pluripotential stem cells in the bone marrow is stimulated by a hormone growth factor called erythropoietin. Erythropoietin is secreted into the bloodstream by kidney cells in response to low oxygen tension in the blood.
During development, red cells loose their nuclei and other cytoplasmic organelles. A reticulocyte is an immature red cell that still retains some cellular organelles. An increased blood reticulocyte count is a useful indicator of increased red blood cell production.

Question 23

Hemoglobin

Answer 23

Major component of red cells. It is composed of two pairs of polypeptide chains, each of which has a heme molecule attached. Oxygen can bind reversibly to an iron molecule at the center of each heme. When fully saturated, a hemoglobin molecule carries four oxygen molecules, and is referred to as oxyhemoglobin.

Question 24

Red blood cell production requires

Answer 24

Adequate amounts of several nutrients., particularly iron, vit. B12 and folate. Lack of intrinsic factor inhibits absorption of b12 from the small intestine and is a risk factor for anemia.

Question 25

Red blood cells rely on

Answer 25

Glycolysis for energy because they do not contain mitochondria. As energy production declines due to red cell aging and loss of essential glycolytic enzymes, the cell swells, gets trapped in the spleen, and is removed from the circulation. Red blood cell degradation releases bilirubin, a toxic substance that is conjugated in the liver and excreted in urine and bile.