Shared Flashcard Set

Details

Hematologic Module
Hematologic Module
56
Medical
Undergraduate 3
04/26/2012

Additional Medical Flashcards

 


 

Cards

Term
Anemia
Definition
A group of disorders characterized by a deficit of RBCs.
Term
Anemia Etiology
Definition
Determining the etiology is based on the history, differential s/s, and lab studies. Differentiating features of the major anemias include the following: aplastic anemia, chronic renal failure, B12 and folate deficiency, iron deficiency, hemolytic, acute blood loss, inherited disorders and other causes.
Term
Aplastic Anemia
Definition
History of toxic or radiation injury to bone marrow, accompanying leukopenia and thrombocytopenia; red cells are normocytic and normochromic.
Term
Chronic Renal Failure
Definition
History of renal disease; decreased erythropoietin level; red cells are normocytic and normochromic. increased serum levels of nitrogen an uremic toxins interfere with erythropoietin activity and red blood cell survival.
Term
B12 and Folate Deficiency
Definition
History of poor intake or GI disease; accompanyingneurologic dysfunction; red cells are megaloblastic (macrocytic).
Term
 Iron Deficiency
Definition
History of poor intake or chronic blood loss; decreased serum ferritin and iron levels; red cells are microcytic and hypochromic.
Term
Hemolytic
Definition
history of ABO of Rh incompatibility or of drug exposure; increased bilirubin, jaundice, and positive direct antiglobulin; red cells are normocytic and normochromic.
Term
Acute Blood Loss
Definition
History of trauma, surgery, or known bleeding; accompanying manifestations of volume depletion; red cells are normal.
Term
Inherited disorders
Definition
Thalassemia, sickle cell, spherocytosis, G6PD deficiency. Predispose red cells to ealry destruction because of abnormalities in hemoglobin structure, cell shape, membrane structure, or energy production; manifestations of hemolysis (e.g., bilirubin, jaundice) are often present.
Term
Other Causes
Definition
Include red cell damage (mechanical devices), infectious agents (malaria), physical agents (burns), venom (insects, spiders, and snakes), and hypersplenism.
Term
Anemia Pathogenesis
Definition
The general effects of anemia are due to tissue hypoxia and efforts to compensate for low oxygen-carrying capacity.
Term
Anemia Manifestations
Definition
Vasoconstriction, pallor, tachypnea, tachycardia, dyspnea, ischemic pain, lethargy, and lightheadedness may be present. S/S specific to the cause may be present.
Term
Chronic Disease Anemia
Definition
involves a decrease in circulating erythrocytes and oxygen carrying capacity of the blood. As a result, tissue hypoxia ensues and creates the symptoms of weakness, fatigue, and dyspnea. CNS hypoxia leads to HA an dizziness. In the elderly individual, cognitive impairment and depression are also indications of hypoxic change in the CNS.
Term
Complete blood Count (CBC)
Definition
gives important information about the kinds of numbers of cells in the blood, especially RBC, WBC and platelets. A CBC helps your doctor check any symptoms, such as weakness, fatigue, or bruising, you may have. A CBC also helps him or her diagnose conditions such as anemia, infection, and many other disorders. A CBC test usually includes: WBC, leukocyte; WBC differential; RBC; HCT, packed cell volume, PCV; Hgb; Red blood cell indices; Platelet count; Mean platelet volume
Term
WBC, leukocyte count
Definition
WBC protect the body against infection. If an infection develops, WBC attack and destroy the bacteria, virus, or other organism causing it. WBC are bigger then RBC but fewer in number. When a person has a bacterial infection, the number of white cells rises very quickly. The number of WBC is sometimes used to find an infection or to see how the body is dealing with cancer treatment.
Term
WBC Differential
Definition
The major types of WBC are neutrophils, lymphocytes, monocytes, eosinophils, and basophils. immature neutrohils, called band neutrophils, are also part of this test. Each type of cell plays a different role in protecting the body. The numbers of each one of these types of white blood cells give important information about the immune system. Too many or too few of the different types of white blood cells can help find an infection, an allergic or toxic reaction to medicines or chemicals, and many conditions, such as leukemia.
Term
Red blood cell (RBC) count.
Definition
Red blood cells carry oxygen from the lungs to the rest of the body. They also carry carbon dioxide back to the lungs so it can be exhaled. If the RBC count is low (anemia), the body may not be getting the oxygen it needs. If the count is too high (a condition called polycythemia), there is a chance that the red blood cells will clump together and block tiny blood vessels (capillaries). This also makes it hard for your red blood cells to carry oxygen.
Term
Hematocrit (HCT, packed cell volume, PCV)
Definition
This test measures the amount of space (volume) red blood cells take up in the blood. The value is given as a percentage of red blood cells in a volume of blood. For example, a hematocrit of 38 means that 38% of the blood's volume is made of red blood cells. Hematocrit and hemoglobin values are the two major tests that show if anemia or polycythemia is present.
Term
Hemoglobin (Hgb)
Definition
The hemoglobin molecule fills up the red blood cells. It carries oxygen and gives the blood cell its red color. The hemoglobin test measures the amount of hemoglobin in blood and is a good measure of the blood's ability to carry oxygen throughout the body.
Term
Red blood cell indices
Definition
There are three red blood cell indices: mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). They are measured by a machine and their values come from other measurements in a CBC. The MCV shows the size of the red blood cells. The MCH value is the amount of hemoglobin in an average red blood cell. The MCHC measures the concentration of hemoglobin in an average red blood cell. These numbers help in the diagnosis of different types of anemia. Red cell distribution width (RDW) can also be measured which shows if the cells are all the same or different sizes or shapes.
Term
Platelet (thrombocyte) count
Definition
Platelets (thrombocytes) are the smallest type of blood cell. They are important in blood clotting. When bleeding occurs, the platelets swell, clump together, and form a sticky plug that helps stop the bleeding. If there are too few platelets, uncontrolled bleeding may be a problem. If there are too many platelets, there is a chance of a blood clot forming in a blood vessel. Also, platelets may be involved in hardening of the arteries (atherosclerosis).
Term
Mean platelet volume (MPV)
Definition
Mean platelet volume measures the average amount (volume) of platelets. Mean platelet volume is used along with platelet count to diagnose some diseases. If the platelet count is normal, the mean platelet volume can still be too high or too low.
Term
A complete blood count may be done to:
Definition
  • Find the cause of symptoms such as fatigue, weakness, fever, bruising, or weight loss.
  • Find anemia.
  • See how much blood has been lost if there is bleeding.
  • Diagnose polycythemia.
  • Find an infection.
  • Diagnose diseases of the blood, such as leukemia.
  • Check how the body is dealing with some types of drug or radiation treatment.
  • Check how abnormal bleeding is affecting the blood cells and counts.
  • Screen for high and low values before a surgery.
  • See if there are too many or too few of certain types of cells. This may help find other conditions, such as too many eosinophils may mean an allergy or asthma is present.

A complete blood count may be done as part of a regular physical examination. A blood count can give valuable information about the general state of your health.

Term
Requirements for blood-Clotting Process
Definition

Presence of platelets produced in the bone marrow

Von Willebrand factor generated by the vessel endothelium

Clotting factors synthesized in the liver using vit K

Term
Platelet Plug formation
Definition

Adhesion and aggregation:

Attraction to a damaged vessel wall

Activation by subendothelial tissue

Change from smooth disks to spiny spheres

Exposure to glycoprotein receptors on their surface

Term
intrinsic and Extrinsic Coagulation Pathways
Definition

Terminal steps in both pathways are the same:

Calcium, factors X and V, and platelet phoopholipids combine to form prothrombin activator.

Prothrombin activator converts prothrombin to thrombin.

this interaction causes conversion of fibrinogen in fibrin strands that create the insoluble blood clot.

Term
Regulation of blood Coagulation
Definition

Antithrmobin III inactivates coagulation factors and neutralizes thrmobin.

when antithrombin III is complexed with naturally occuring heparin, its action is accelerated and provides protection against uncontrolled thrombus formation on the endothelial surface.

Protein C, a plasma protein, acts as an anticoagulant by inactivating factors V and VIII.

Protein S, another plasma protein, accelerates the action of protein C.

Plasmin breaks down fibrin into fibrin degradation products that act as anticoagulants.

Term
Thrombosis
Definition
the inappropriate formation of clots within the vascular system
Term
Bleeding
Definition
Failure of blood to clot in response to appropriate stimulus
Term
conditions that create increased platelet function
Definition

Atherosclerosis

DM

Smoking

Elevated blood lipoid and cholesterol levels

increased platelet levels

Term
conditions that cause accelerated activity of the coagulation system
Definition

pregnancy and the puerperium

use of oral contraceptives

post-surgical state

immobility

congestive heart failure

malignant diseases

 

Term
Hypercoagulability States
Definition

Increase the risk of clot or thrombus formation on the arterial or venous circulation.

Arterial thrombi are associated with conditions that produce turbulent blood flow and platelet adherence.

Venous thrombi are associated with conditions that cause stasis of blood flow with increased concentrations of coagulation factors

Term
Causes of bleeding
Definition

Decrease in the number of circulating platelets: depletion of platelets must be relatively severe before hemorrhagic tendencies of spontaneous bleeding occur.

Impaired platelet function: bleeding resulting from platelet deficiency commonly occurs in small vessels and is characterized by petechiae and purpura

Term
Platelet Defects
Definition

Thrombocytopenia: results from a decrease in platelet production, increased sequestration of platelets in the spleen, or decreased platelet survival. Types: Drug-induced thrombocytopenia; Idiopathic thrombocytopenic purpura; Thrombotic thrombocytopenic purpura.

Impaired platelet function.

Term
Manifestations of Thrombocytopenia
Definition
Bleeding: mucous membranes; nose, mouth, GI tract, and uterine cavity; commonly occurs in small vessels; petechiae: pinpoint purplish-red spots; seen almost exclusively in conditions of platelet deficiency. Purpura: purple areas of bruising
Term
Thrombocytopenia may be caused by all of the following:
Definition
Auto antibodies, Drug hypersensitivities, bacterial infections that decrease platelet production
Term
coagulation and vitamin K
Definition
Vitamin K is an essential cofactor for synthesis of clotting factors. Fat-soluble vitamin synthesized by intestinal bacteria. in vitmain K deficiency, the liver produces inactive clotting factor, resulting in abnormal bleeding.
Term
Coagulation Defects
Definition

Deficiencies can arise becuase of defective synthesis, inherited disease, or increased consumption of the clotting factors.

Hereditary disorders: hemophilia A, hemophilia B, Von willebrand disease, any genetic disruption of the production of clotting factor

Term
Von Willebrand disease is caused by:
Definition
deficiency of factor VIII and poor platelet function: these two conditions together cause the disseminated bleeding
Term
Hemorrhagic telangiectasia
Definition
an uncommon autosomal-dominant disorder characterized by thin-walled, dilated capillaries and arterioles
Term
Vitamin C Deficiency (scurvy)
Definition
results in poor colagen synthesis and failure of the endothelial cells to adhere to one another properly, causing a fragile wall
Term
cushing disease
Definition
causes protein wasting and loss of vessel tissue support becuase of excess cortisol
Term
senile purpura (bruising in elderly persons)
Definition
caused by the aging process
Term
Stasis
Definition
leads to an accumulation of activated clotting factors and platelets.  The end result is increased risk for thrombus formation.
Term
Atherosclerosis
Definition
increases platelet function by encouraging aggregation and adherence.
Term
Immobility
Definition
immobility also decreases chemical interactions with coagulation inhibitors. contributes to hypercoagulability by increasing procoagulation factors
Term
Neutropenia
Definition

is a hematological disorder characterized by an abnormally low number of neutrophils, the most important type of white blood cell, in the blood. Neutrophils usually make up 50-70% of circulating white blood cells and serve as the primary defense against infections by destroying bacteria in the blood. Hence, patients with neutropenia are more susceptible to bacterial infections and, without prompt medical attention, the condition may become life-threatening (neutropenic sepsis).

Neutropenia can be acute or chronic depending on the duration of the illness. A patient has chronic neutropenia if the condition lasts for longer than 3 months. It is sometimes used interchangeably with the term leukopenia ("deficit in the number of white blood cells"), as neutrophils are the most abundant leukocytes, but neutropenia is more properly considered a subset of leukopenia as a whole.

There are numerous causes of neutropenia that can roughly be divided between either problems in the production of the cells by the bone marrow and destruction of the cells elsewhere in the body. Treatment depends on the nature of the cause, and emphasis is placed on the prevention and treatment of infection.


Neutropenia can go undetected, but is generally discovered when a patient has developed severe infections or sepsis. Some common infections can take an unexpected course in neutropenic patients; formation of pus, for example, can be notably absent, as this requires circulating neutrophil granulocytes.

Some common symptoms of neutropenia include fevers and frequent infections. These infections can result in conditions such as mouth ulcers, diarrhea, a burning sensation when urinating, unusual redness, pain, or swelling around a wound, or a sore throat.

"Neutropenia" is a condition in which the number of neutrophils in the bloodstream is decreased. Neutrophils are a type of white blood cell also known as polymorphonuclear leukocytes or PMNs. Neutropenia affects the body's ability to fight off infections.

White blood cells are also known as leukocytes. There are five major types of white blood cells:

  1. basophils,
  2. eosinophils,
  3. lymphocytes (T-cells and B-cells),

  4. monocytes, and
  5. neutrophils.

Some white blood cells, called granulocytes, are filled with microscopic granules that are little sacs containing enzymes (compounds that digest microorganisms). Neutrophils, eosinophils, and basophils are all granulocytes and are part of the innate immune system with somewhat nonspecific, broad-based activity. They do not respond exclusively to specific antigens, as do the lymphocytes (B-cells and T-cells).

Neutrophils contain enzymes that help the cell kill and digest microorganisms it has engulfed by a process known as phagocytosis. The mature neutrophil has a segmented nucleus (it is often called a 'seg' or 'poly'), while the immature neutrophil has a band-shape nucleus (it is called a band). Neutrophils are made in the bone marrow and released into the bloodstream. The neutrophil has a life-span of about three days.

Term
Neutropenia causes can be divided into the following groups:
Definition

Decreased production in the bone marrow

Increased destruction

Term
Decreased production in the bone marrow:
Definition
  • aplastic anemia
  • cancer, particularly blood cancers
  • certain medications
  • hereditary disorders (e.g. congenital neutropenia, cyclic neutropenia)
  • radiation
  • Vitamin B12 or folate deficiency.
Term
Increased destruction:
Definition
  • Autoimmune neutropenia.
  • chemotherapy treatments, such as for cancer and autoimmune diseases
Term

How is neutropenia defined?

Definition

The white blood cell count (WBC) is the number of white blood cells in a volume of blood. The normal range for the WBC varies slightly among laboratories but is generally between 4,300 and 10,800 cells per microliter or cubic millimeter (cmm). The WBC can also be referred to as the leukocyte count and can be expressed in international units as 4.3 x 109to 10.8 x 109 cells per liter. The percentage of the different types of white blood cells in the WBC is called the WBC differential.

The absolute neutrophil count (ANC) is determined by the product of the white blood cell count (WBC) and the fraction of neutrophils among the white blood cells as determined by the WBC differential analysis. For example, if the WBC is 10,000 per microliter and 70% are neutrophils, the ANC would be 7,000 per microliter.

An ANC of less than 1500 per microliter (1500/microL) is the generally accepted definition of neutropenia. Neutropenia is sometimes further classified as:

  • mild if the ANC ranges from 1000-1500/microL,

  • moderate with an ANC of 500-1000/microL, and

  • severe if the ANC is below 500/microL.

Some medical terms may be used synonymously with neutropenia, even though their precise definitions are different.

  • Leukopenia refers to a reduced number of white blood cells in general, while granulocytopenia refers to a decreased number of all the granulocyte-type blood cells (neutrophils, eosinophils, and basophils).

  • Since neutrophils normally far outnumber the other types of granulocytes, this term is sometimes used to refer to neutropenia.

  • Finally, agranulocytosis literally refers to a complete absence of all granulocytes, but this term is sometimes used to refer to severe neutropenia.
Term

What are the clinical consequences of neutropenia?

Definition

Neutropenia results in an increased susceptibility to bacterial infections. The degree of risk depends upon the cause and severity of the neutropenia, the underlying medical condition of the patient, and the presence or absence of bone marrow reserves for the production of neutrophils.

The most common type of infections seen in neutropenic patients are caused by bacteria normally found on the skin (such as Staphylococcus aureus) or from the gastrointestinal and urinary tract. Fungal infections are also more frequent in patients with neutropenia. The infections may be limited to certain areas of the body (commonly the oral cavity, genital area, and skin) or may spread via the bloodstream to the lungs and other organs in severe, prolonged neutropenia.

Term

What causes neutropenia?

Definition

Neutropenia can be present (though it is relatively uncommon) in normal healthy individuals, notably in some persons of African or Arabic descent and and Yemenite Jews. Neutropenia may arise as a result of decreased production of neutrophils, destruction of neutrophils after they are produced, or pooling of neutrophils (accumulation of the neutrophils out of the circulation).

Neutropenia may arise as a result of numerous medical conditions:

  • Infections (more commonly viral infections, but also bacterial or parasitic infections). Examples include: HIV, tuberculosis, malaria, Epstein Barr virus (EBV);

  • Medications that may damage the bone marrow or neutrophils, including cancer chemotherapy;

  • Vitamin deficiencies (megaloblastic anemia due to vitamin B12 and/or folate deficiency);

  • Diseases of the bone marrow such as leukemias, myelodysplastic syndrome, aplastic anemia, myelofibrosis;

  • Radiation therapy;

  • Congenital (inborn) disorders of bone marrow function or of neutrophil production, for example, Kostmann syndrome;

  • Autoimmune destruction of neutrophils (either as a primary condition or associated with another disease such as Felty's syndrome) or from drugs stimulating the immune system to attack the cells

  • Hypersplenism, which refers to the increased sequestration and/or destruction of blood cells by the spleen
Term

How is neutropenia diagnosed?

Definition
Neutropenia is diagnosed by a blood cell count performed on a sample of blood removed from a vein. To determine the specific cause of neutropenia in a given situation, other tests may be required. Sometimes a bone marrow biopsy may be required to diagnose the specific cause of neutropenia.
Term

How is neutropenia treated?

 

Definition

Treatment of neutropenia is based upon the underlying cause, severity, and the presence of associated infections or symptoms as well as the overall health status of the patient. Obviously, treatment must also be directed toward any underlying disease process. Treatments that directly address neutropenia may include (note that all of these treatments may not be appropriate in a given setting):

  • antibiotic and/or antifungal medications to help fight infections;

  • administration of white blood cells growth factors (such as recombinant granulocyte colony-stimulating factor (G-CSF, filgrastim) in some cases of severe neutropenia;

  • granulocyte transfusions; or

  • corticosteroid therapy or intravenous immune globulin for some cases of immune-mediated neutropenia.

Preventive measures may also be implemented in neutropenic patients to limit risk of infections. These measures might include strict attention to hand washing, use of private rooms, or in some cases, use of gloves, gowns, and/or face masks by caregivers.

Term
Neutropenia At A Glance
Definition
  • Neutropenia is a condition in which the number of neutrophils (a type of white blood cell) in the bloodstream is decreased, affecting the body's ability to fight off infections.

  • Neutropenia is defined as an absolute neutrophil count (ANC) of less than 1500 per microliter (1500/microL)

  • Neutropenia may be caused by or associated with numerous medical conditions

  • Most infections that occur as a result of neutropenia are due to bacteria that are normally present on the skin or in the gastrointestinal or urinary tract.

  • Treatment depends upon the cause and severity of he condition as well as the underlying disease state responsible for the neutropenia.
Supporting users have an ad free experience!