Pathophysiology unit one study guide


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Pathophysiology unit one study guide

  1. 1. PATHOPHYSIOLOGYUNIT ONE STUDY GUIDEANC (absolute neutrophil count)— the percentage of the total white blood cell count that is made up of neutrophils that defend our bodies against infection.Anemia—a lower-than-normal number of red cells in the blood. Red blood cells are important because they carry oxygen from the lungs to all other cells in the body.Shortness of breath, fatigue, and weakness are signs of anemia.Bacteria—The smallest forms of life. Bacteria are the most common causes of infections in people with cancer. Some types of bacteria include Klebsiella pneumonia,Escherichia coli (E. coli), and salmonella.Chemotherapy—The use of drugs to destroy cancer cells. A person on chemotherapy may take one drug or a combination of drugs. Most often these drugs are given byvein using intravenous (IV) infusion. Some can be taken by mouth or given in a shot.Chemotherapy regimen—A plan of drug treatment, including doses, scheduling, and duration of administration.Colony-stimulating factors—Also called CSFs, colony-stimulating factors are drugs that promote the production of various blood cells. Examples of CSFs areNEUPOGEN® (filgrastim) and Neulasta® (pegfilgrastim).CBC (complete blood count)—The CBC is a test that determines the number of red blood cells, white blood cells, and platelets in the blood.Dose delay—Stopping a treatment regimen for a period of time. Febrile neutropenia is a common cause of chemotherapy dose delays.Dose reduction—Decreasing the amount of medication during treatment. Febrile neutropenia is a common cause of chemotherapy dose reductions.Febrile neutropenia—Having a fever and a low white blood cell count (neutropenia). Having a fever during neutropenia is often a sign of infection.Hb (hemoglobin)—The part of the red blood cell that carries oxygen from the lungs to other organs in the body, such as the brain and the heart. A person with a lowhemoglobin level may have anemia. Written as Hb or Hgb on CBC reports.Hct (hematocrit)—A blood test that measures the number of red blood cells in the bloodstream. The lower the hematocrit, the lower the number of red blood cells in theblood. A person with a low hematocrit may have anemia. Written as Hct on CBC reports.Hospitalization for febrile neutropenia—Febrile neutropenia that is severe enough to send you to the hospital.Infection—An invasion of microorganisms that have the ability to multiply and produce disease.IV (intravenous)—Into a vein. An intravenous medication is delivered into the body through a vein.Lymphoma—Cancer that begins in cells of the immune system.Myelosuppressive—Causing the blood marrow to slow production of blood cells. This results in fewer red blood cells, white blood cells, or platelets available toperform their normal functions in the body. Chemotherapy can cause decreased bone marrow function. Most often, myelosuppression refers to the loss of white bloodcellsNeulasta® (pegfilgrastim)—A prescription medicine used to help reduce the risk of infection (initially marked by fever) in patients with some tumors receiving strongchemotherapy that decreases the number of infection-fighting white blood cells.NEUPOGEN® (filgrastim)—A prescription medicine used to help reduce the risk of infection (initially marked by fever) in patients with some tumors receiving strongchemotherapy that decreases the number of infection-fighting white blood cells.Neutropenia—Neutropenia occurs if there is a lower-than-normal number of neutrophils (infection-fighting white blood cells) in the blood. It is a common side effect ofsome chemotherapy treatment. Doctors check the number of neutrophils when they measure the white blood cell count, to monitor the risk of infection.Neutrophil—The most common type of white blood cell. Neutrophils help the body fight infection. A low white blood cell count usually indicates that the neutrophilcount is low. It is easier to get an infection and harder to recover from an infection when the number of neutrophils in the bloodstream is low.Oncologist—A doctor who specializes in the treatment of cancer.Oncology—The branch of medicine that focuses on the study and treatment of cancer.Platelets—One of the 3 types of cells made in the bone marrow. The main function of platelets is to aid in clotting the blood following an injury.Radiation—The use of radioactive substances for the diagnosis or treatment of diseases.RBC (red blood cell)—Red blood cells are made in the bone marrow and released into the blood. They circulate in the blood and carry oxygen and carbon dioxide toand from every cell in the body.
  2. 2. Risk factor—Anything that increases the chance of getting a certain disease, such as cancer. Some risk factors are genetic while others are environmental.Side effect—Any undesired actions or effects of a drug or treatment. For example, common side effects of chemotherapy include fatigue, nausea, vomiting, and loss ofappetite.Treatment schedule—How often and how much medication you will receive to treat your disease.Thrombocytopenia—A condition resulting from an abnormally low number of platelets (thrombocytes) circulating in the blood. Bleeding and/or bruising may occur ifthe platelet count is especially low.Virus—The smallest known germ and a common cause of infection. Unlike bacteria, viruses cannot grow on their own. Viruses can only make new viruses when theyare inside living cells, such as human cells.WBC (white blood cell)—A white blood cell is one of the three main types of blood cells. White blood cells are responsible for fighting infection. There are severalkinds of white blood cells, including monocytes, lymphocytes, neutrophils, eosinophils, and basophils.Immature CellsImmature white blood cells are called "bands" or "stabs." They normally compose 3 to 5 percent of the total white blood cell count. If the body has an acute problem,such as a strong infection, the percent will be higher as the bone marrow makes a large number of new cells. Your body makes around 100 billion immature white bloodcells each day.Kidney Cancer Signs Worried About Kidney Cancer? Learn The Common Signs Now. Links NeutrophilsNeutrophils are the main type of white blood cell in the healthy adult. They have granules inside, making them granulocytes. According to Merck Manual, these cellsdestroy and ingest fungi and bacteria in the body. They also digest harmful debris, such as dirt that enters a wound. Neutrophils are considered to be infection-fighters.Neutrophils normally compose 50 to 70 percent of the white blood cell count. An elevated neutrophil count is called neutrophilia.EosinophilsEosinophils also have granules, making them granulocytes. These WBCs normally compose 1 to 3 percent of the total white blood cell count. Eosinophils destroycancer cells and parasites. They also play a complex role in your bodys allergic response. A high level of eosinophils in the blood is called eosinophilia.BasophilsBasophils are the final type of granulocytes. These white blood cells typically compose only 0.4 to 1 percent of total WBCs. Basophils help fight infection and play acomplex role in the allergic response. An increase in basophils is called basophilia.LymphocytesLymphocytes do not contain granules, which means they are part of the kind of white blood cells called agranulocytes. Lymphocytes comprise 25 to 35 percent of thetotal WBC count in a healthy adult. There are three main types of lymphocytes: B lymphocytes, T lymphocytes and natural killer cells. B lymphocytes, when needed,release a protein called an antibody that fights bacteria, parasites and viruses. B lymphocytes may also attack a transplanted organ, thinking it is a foreign invader. Tlymphocytes fight viruses in the body, as do natural killer cells. Both of these lymphocytes can also destroy some types of cancer cells. An elevated level oflymphocytes is called lymphocytosis.MonocytesMonocytes are also considered to be agranulocytes. In a healthy adult, 4 to 6 percent of WBCs are monocytes. Merck Manual explains that these WBCs protect youfrom a large number of infectious organisms in the body and also ingest damaged and dead cells. A high number of monocytes is called monocytosis.Study Guide Test 2Anemia – a reduction in the total number of erythrocytes in the circulating blood or a decrease in the quality or quantity of hemoglobin.Pernicious anemia is associated with end-stage type A chronic atrophic gastritis, but is the result of an autoimmune disorder, not a viral infection. It is due to theabsence of intrinsic factor and generally occurs in the elderly with mean age of onset of age 60.Adequate dietary intake of folate is between 50 to 200 micrograms/day. Pregnant women require more folate. Folate synthesis takes place in the human intestine, andabsorption occurs in the small intestine.Albumin (about 60% of total plasma protein) serves as a carrier molecule for both normal components of blood and drugs. Its most essential role is regulation of thepassage of water and solutes through the capillaries through the process of osmosis, not intravascular pressure.Fibrinogen is the most plentiful of the clotting factors and is the precursor of the fibrin clot.Plasma is a complex aqueous liquid containing a variety of organic and inorganic elements.
  3. 3. Erythrocytes (red blood cells) are the most abundant cells of the blood, occupying approximately 48% of the blood volume in men and about 42% in women.Erythrocytes are primarily responsible for tissue and cellular oxygenation.Hemoglobin (Hb) carries the gases, and electrolytes regulate gas diffusion through the cell’s plasma membrane.White blood cells (leukocytes) are involved in infection control.Platelets (thrombocytes) are essential for blood coagulation and control of bleeding. Platelets are involved with hemorrhage control.Leukocytes are involved in phagocytosis, which is the killing and removal of cellular waste.Hemoglobin (Hb), the oxygen-carrying protein of the erythrocyte, takes up oxygen in the lungs and exchanges it for carbon dioxide in the tissues.Neutrophils are instrumental in the initiation of the inflammatory process.The continuous movement of blood guarantees that critical components are available to all parts of the body to carry out their chief functions: (1) delivery of substancesneeded for cellular metabolism in the tissues, (2) removal of the wastes of cellular metabolism, (3) defense against invading microorganisms and injury, and (4)maintenance of acid-base balance.Leukocytes (white blood cells) defend the body against organisms that cause infection and also remove debris, including dead or injured host cells of all kinds. Theleukocytes act primarily in the tissues but are transported in the circulation. The average adult has approximately 5,000 to 10,000 leukocytes/mm3 of blood. Leukocytesare classified according to structure as either granulocytes or agranulocytes.The neutrophil (polymorphonuclear neutrophil [PMN]) is the most numerous and best understood of the granulocytes. Neutrophils are the chief phagocytes of earlyinflammation. Soon after bacterial invasion or tissue injury, neutrophils migrate out of the capillaries and into the damaged tissue, where they ingest and destroycontaminating microorganisms and debris. Neutrophils are sensitive to the environment in damaged tissue and die in 1 or 2 days. The breakdown of dead neutrophilsreleases digestive enzymes from their cytoplasmic granules. These enzymes dissolve cellular debris and prepare the site for healing.The spleen, the largest of the lymphoid organs, is located in the left upper abdominal cavity and is about the size of a fist. Its lymphocytes mount immune responses toblood-borne microorganisms, and it serves as a blood reservoir. The spleen is not necessary for life or for adequate hematologic function, but its absence is reflected inhow the body functions.The typical human requires about 100 billion new blood cells per day. Blood cell production, termed hematopoiesis, is constantly ongoing, occurring in the liver andspleen of the fetus and only in bone marrow after birth. This process involves the biochemical stimulation of populations of relatively undifferentiated cells to undergomitotic division (i.e., proliferation) and maturation (i.e., differentiation) into mature hematologic cells. Hematopoiesis continues throughout life, increasing in responseto proliferative disease, hemorrhage, hemolytic anemia (in which erythrocytes are destroyed), and chronic infection.Sideroblasticanemias are a heterogeneous group of disorders characterized by anemia of varying severity due to a dysfunction in the erythroid cells that results in afaulty production of heme.Iron deficiency anemia is usually a result of pregnancy or caused by a continuous loss of blood.Microcytic-hypochromic anemia is caused by small erythrocytes that contain reduced amounts of hemoglobin.Megaloblastic anemia is caused by unusually large erythrocytes.Polycythemia is the medical term for abnormally high production of red blood cells.Hemolytic crisis is fulminate hemolytic anemia and can present with shock.Apoferritin is a protein implicated in altered iron metabolism.Infectious mononucleosis is typically caused by the herpes virus and EBV, which accounts for approximately 85% of IM cases. It usually affects young adults between15 and 35 years of age. There is characteristically an increase in lymphocytes.The most common leukemia in children is ALL and represents 80% of the leukemia in children. All other forms are much more commonly diagnosed in adults.Lymphomas are initially identified by the presence of tender, lymph nodes that are enlarged enough to be palpated. They are the sixth most common cause of cancerdeath and are the result of injury to the DNA of the lymphoid tissue.Malignancy within the lymphatic tissue in the bone marrow is termed lymphocytic leukemia.The peak incidence occurs during the early 20s and 30s and again in the sixth and seventh decades of life. The incidence is greatest in whites and economicallyadvantaged countries. There is an increase in Reed-Steinberg cells.Burkitt lymphoma is a type of non-Hodgkin lymphoma and is the most common in children from east-central Africa and New Guinea. It is very fast growing andinvolves primarily the jaw and facial bones. It is associated with Epstein-Barr virus..With a platelet count of less than 10,000, severe bleeding without trauma may result. It is unlikely that such a bleeding will occur at the other levels.
  4. 4. Heparin is the most common cause of drug-induced thrombocytopenia because of its affect on the clotting of human blood. The other choices are not known to causethrombocytopenia.Immune thrombocytopenic purpura (ITP) is more common in females between 20 and 40 years of age. It usually starts with minor problems such as petechiae and aninitial platelet count of 150,000.Iron deficiency anemia is common in children due to their extremely high need for iron for growth. Incidence is not related to race but is increased in the children ofhomeless women most likely due to poor nutrition. It is most commonly found between the ages of 6 months and 2 years. Splenomegaly is evident in only 10% to 15%of children with iron deficiency anemia. If the condition is longstanding, the sutures may widen. Mild to moderate iron deficiency (hemoglobin 6 g/dl to 10 g/dl) mayshow some cellular changes. Hemoglobin less than 8 g/dl can demonstrate pallor, tachycardia, and a systolic murmur.Microcytic-hypochromic anemia is known to be a result of disorders involving: Research supports that microcytic-hypochromic anemia is a result of disordersinvolving iron metabolism, porphyrin synthesis, heme production, and globin synthesis.The inability to absorb vitamin B12 results in pernicious anemia, which is a microcytic-normochromic anemia.The causes of neutropenia, in addition to an overwhelming infection, include decreased production, increased turnover, and abnormal distribution. Decreased vitaminintake can cause decreased production due to the lack of appropriate building blocks.Asthma, eczema, and atopic dermatitis may all increase eosinophils production resulting in eosinophilia. Prolonged infection may actually cause leukopenia, while poorprotein intake has no known relationship to eosinophilia.Lymphadenopathy may be caused by neoplastic disease, immunologic or inflammatory conditions, endocrine disorders, and lipid storage disease. Currently there is noresearch to support a connection between cardiac disease and lymphadenopathy.The criteria for the diagnosis of an overactive spleen include anemia, thrombocytopenia, an enlarged spleen, and cellular bone marrow. Leukopenia, not leukocytosis, isa recognized criterion for such a condition.Thrombotic thrombocytopenic purpura (TTP) is a result of platelet clumping seen most commonly in adult females. While reported cases of TTP are increasing, thecause is yet to be identified. It is rarely observed in infants and is certainly life threatening if not treated effectively and promptly.The prothrombin factors that are affected by vitamin K include II, VII, IX, and X.The triad of Virchow includes the factors that predispose to thrombus formation and include injury to the endothelium, abnormalities of blood flow, andhypercoagulability of the blood. The condition is not affected by either a decrease in clotting factor or poor vitamin A absorption.Anemia, not sickle cell disease, is the most common blood disorder in children. The most common cause of anemia is iron deficiency. There are two large categories forhemolytic anemia, including increased destruction and disorders related to damaging extraerythrocytic factors.Anti-Rh antibodies are formed only in response to the presence of incompatible (Rh-positive) erythrocytes in the blood of an Rh-negative mother. Sources of exposureinclude fetal blood that is mixed with the mother’s blood at the time of delivery, transfused blood, and, rarely, previous sensitization of the mother by her own mother’sincompatible blood. ABO incompatibility can cause hemolytic disease of the newborn without erythrocytes escaping maternal circulation. Placental detachment resultsin a large number of fetal erythrocytes entering the mother’s bloodstream. The first Rh-incompatible pregnancy usually presents with no difficulties. Anti-Rh antibodiesare formed in response to the presence of incompatible (Rh-positive) erythrocytes in the blood of an Rh-negative mother.Which condition is accurately defined as ―the release of immature nucleated red cells into the bloodstream‖? The definition in the stem is that of erythroblastosisfetalis.Hydropsfetalis is the term for fetuses that do not survive anemia in utero and are stillborn with gross edema of the entire body. Icterus neonatorum is neonatal jaundice.Icterus gravis neonatorum is death due to cerebral damage secondary to bilirubin deposition on brain.The indirect Coombs measures antibody in the mother’s circulation and indicates if the fetus is at risk for hemolytic disease. The direct Coombs test measuresantibodies already bound to the surfaces of fetal erythrocytes and is used primarily to confirm the diagnosis of antibody-mediated hemolytic disease.Sickle cell thalassemia is characterized by two Hgb abnormalities, one involving the Hb(s) gene. Sickle cell anemia has two Hb(s) genes. Sickle cell trait has one Hband one normal Hg(A). Hereditary spherocytosis often represents a new mutation.Sickle cell disease is an autosomal recessive disease. It is most common in central Africa, the Near East, the Mediterranean, and part of India. In sickle cell disease, thepatient has two Hb(s) genes, and this represents the homozygous form of this disease.Hypoxemia is the most common cause of sickling. Currently, there is no research to support that the other options trigger sickling.Aplastic crisis is a profound anemia caused by diminished erythropoiesis despite an increased need for new erythrocytes. Vaso-occlusive crisis may developspontaneously or be precipitated by infection, cold temperatures, dehydration, or low pH. This is when the cells clump and occlude vessels. Sequestration crisis is whenlarge amounts of the blood become pooled in the liver and spleen. Hyperhemolytic crisis is unusual and often occurs with G6PD.About 90% to 95% of hemorrhagic bleeding disorders are caused by clotting factors VIII, IX, and XI. There is no current research to support the role of the otheroptions in the development of hemophilia.Hemophilia is a condition characterized by impairment of the coagulation of blood and a subsequent tendency to bleed. The classic disease is hereditary and limited tomales, being transmitted through the female to the second generation.
  5. 5. Statistics show that non-Hodgkin lymphoma NHL occurs more often than Hodgkin lymphoma. The disease is rare before the age of 5 years. At particular risk arechildren with inherited or acquired immunodeficiency syndromes. NHL is a rapidly progressing disease; symptoms generally are present only a few weeks beforediagnosis is made. Symptoms often include abdominal pain and vomiting, but a palpable mass is not always present.The onset of leukemia may be abrupt or insidious, but the most common symptoms reflect the consequence of bone marrow failure: decreased red blood cells andplatelets and changes in white blood cells. Pallor, fatigue, petechiae, purpura, bleeding, and fever generally are present. Approximately 45% of children have ahemoglobin level below 7 g/dl.The circumflex travels in the coronary sulcus. The left anterior descending travels down the anterior surface of the interventricular septum. The right coronary arteryoriginates from an ostium behind the right aortic cusp and travels behind the pulmonary artery. The left coronary artery passes between the left atrial appendage and thepulmonary artery and generally divides into two branches.The SA node contains P cells and is the site of impulse formation. The atrioventricular node is the junction of the electrical transmission between the atria and theventricles. The bundle of His is the next stop, and then the transmission branches to the right and left bundle branches. The terminal branches are the Purkinje fibers.The PR interval measures the time of onset of atrial activation to the onset of ventricular activation. The QRS complex represents the sum of all ventricular muscle celldepolarizations. The ST interval is the time when the entire ventricular myocardium is depolarized. The QT interval is often called the electrical systole.The A band is the thick filaments that form a dark band. The I band is the light band. The letter I stands for isotropic. The Z line is a dense fibrous band that crosses thecenter of each I band. The M line is a thin dark line that travels the center of the H zone. The H zone is in the center of the sarcomere and is somewhat less dense.Calcium channel blockers block the calcium channel, prohibiting the movement of calcium into the myocardial cell. Calcium is necessary for the activation ofexcitation-contraction coupling; blocking this will decrease the strength of contraction. The other drugs are not known to have that relationship to calcium blocking.The Frank-Starling law of the heart relates to resting sarcomere length (expressed as the volume of blood in the heart at the end of diastole or end-diastolic volume) totension generation (development of left ventricular pressure). In summary, this means the volume of blood in the heart at the end of diastole is directly related to theforce of contraction of the next systole. The other options do not relate to this law.Preload is the pressure generated in the left ventricle at the end of diastole. Afterload is the resistance or impedance to ejection of blood from the left ventricle. Atension curve lower than normal is characteristic of congestive heart failure. Wall tension is directly related to the product of the intraventricular pressure and internalradius and inversely to the wall thickness (Laplace Law).Parasympathetic excitation slows heart rate and is often referred to as the cardioinhibitory center. Sympathetic stimulation is often called the cardioexcitation centerbecause the heart rate increases. The Bainbridge reflex causes the heart rate to increase after intravenous infusions of blood or fluid. The baroreceptor reflex facilitatesblood pressure changes and heart rate changes.Atrial natriuretic peptide is released from atrial tissue in response to increases in blood volume. Epinephrine and norepinephrine are catecholamines and part of thesympathetic system. Thyroid hormone enhances sympathetic activity.What two factors determine cardiac output? Cardiac output is directly related to heart rate and stroke volume. Changes in either variable affect the cardiac output. Theremaining options are not involved in determining cardiac output.Which structure is the source of nutrients for the blood vessels? The vasa vasorum are small vessels located in the tunica externa (adventitia). They providenourishment to the cells of the larger vessels. The tunica intima is the inner layer, tunica media middle layer, and tunica externa outer layer.The MAP measures the average pressures in the arteries throughout the cardiac cycle. Vascular compliance is volume ¿ pressure (VP). Poiseuilles Law calculates fluidflow through a tube and is represented by blood flow (Q) = (pressure1 - pressure2)/resistance (R). Laplaces equation measures wall tension by the equation pressure ¿radius/wall thickness.A decrease in blood pressure at the renal artery causes increased renin release.Angiotensin II is a potent vasoconstrictor, not a dilator, and causes the stimulation of aldosterone. Aldosterone causes reabsorption of the sodium from the kidneys.Urodilantin is a natriuretic peptide isolated from urine. It acts as a paracrine intrarenal regulator for sodium and water balance. BNP is a proposed marker for leftventricular dysfunction. ANP is an indicator of blood pressure elevation. C-type natriuretic peptide is expressed throughout the vasculature.Lymph, primarily water and small amounts of protein, is reabsorbed through the lymph nodes and delivered to either the right lymphatic duct (lymph from right arm,head, and thorax) or the thoracic duct (rest of the body). These structures in turn dump the lymph into the inferior and superior vena cavae, where it enters back intosystemic circulation.The endocardium is the lining that is continuous with the arteries, veins, and capillaries of the body. The pericardium is a double-walled membranous sac that has nomusculature. The functions of the pericardium are: A) prevents displacement of the heart during gravitational acceleration/deceleration. B) acts as a physical barrier thatprotects the heart against infection and inflammation. C) contains pain receptors and mechanoreceptors that affect blood pressure. D) brings about the force required tonormalize blood pressure.Autoregulation ensures adequate coronary blood flow between 60 mmHg and 180 mmHg. The blood vessels regulate their own flow through arteriolar resistance,resulting from the smooth muscle constriction of those vessels.
  6. 6. The heart consists of four chambers (two atria and two ventricles), four valves (two atrioventricular valves and two semilunar valves), and a muscular heart wall madeup of three layers: the pericardium (outer layer), the myocardium (muscular layer), and the endocardium (inner lining).Identify the pathway that deoxygenated blood returning through the superior and inferior venae cavae takes to the lung of re-oxygenation? A begins the pathway and Eends it. Deoxygenated (venous) blood from the systemic circulation enters the right atrium through the superior and inferior venae cavae. From the atrium, the bloodpasses through the right atrioventricular (tricuspid) valve into the right ventricle. In the ventricle, the blood flows from the inflow tract to the outflow tract and thenthrough the pulmonary semilunar valve (pulmonary valve) into the pulmonary artery, which delivers it to the lungs for oxygenation.Arteriosclerosis is a chronic degeneration of blood vessel walls. A plaque is caused by collagen over a fatty streak that is composed of a large number of lipid-ladenfoam cells that deposit on the vessel wall.A patient experiences an elevated systolic pressure accompanied by normal diastolic pressure (below 90 mmHg). Which is the correct term for this condition?Isolated systolic hypertension is an elevated systolic pressure with a normal diastolic pressure. Primary hypertension has no known cause. Secondary hypertension iscaused by altered hemodynamics. There is no tertiary hypertension.A condition in which blood has pooled, producing distended and palpable vessels, is referred to as Varicose veins. Thrombus is a blood clot that remains attached to avessel wall. Venous stasis ulcers are caused by cell death and necrosis secondary to trauma or pressure-induced oxygen deficiency. Deep vein thrombosis is a thrombusformation occurring mainly in the lower extremities.Complications of hypertension include ventricular hypertrophy, angina pectoris, congestive heart failure, coronary artery disease, myocardial infarction, and suddendeath. There is no research to support the remaining options as occurring as a result of hypertension.Which term describes the occlusion of a blood vessel from a bolus of circulating matter in the bloodstream? An embolus detaches from the wall of a vessel andcirculates within the vascular system until it reaches a vessel small enough for it to occlude. A thrombus is a blood clot that remains attached to the vessel wall.Thrombophlebitis is the inflammation caused by a thrombus. Foam cells are lipid-laden cells that contribute to fatty streaks.A young woman presents with pallor, numbness, and a sensation of cold temperature of her digits. Which condition is the most likely cause for these symptoms?Raynaud phenomenon is characterized by attacks of vasospasm in the small arteries of the fingers that causes cold numb digits. Thromboangiitisobliterans is aninflammatory disease of the peripheral arteries that tends to occur in young men who are heavy smokers. Peripheral vascular disease is a result of atherosclerosis.Varicose veins have pooled blood.Which conditions are associated with dyslipidemia? Very low-density lipoproteins (VLDL) is associated with triglycerides and protein. Low-density lipoproteins(LDL) is associated with cholesterol and protein. High-density lipoprotein (HDL) is associated with phospholipids and protein. Chylomicrons are dietary fat packages.Cigarette smoking produces an increased LDL level and thrombotic and inflammatory state and decreased HDL.A patient presents with chest pain that occurs at rest. Abnormal vasospasm of the coronary arteries is detected. Which is the most likely cause of the chest pain?Prinzmetal angina is an abnormal vasospasm of the coronary vessels. It typically produces pain at rest and is common in women. Stable angina occurs with activity andis often limited and resolves with rest. Silent ischemia is occlusion of the coronary arteries without pain. Angina pectoris is chest pain, usually substernal chestdiscomfort.Cardiac cells can withstand ischemic conditions for about 20 minutes. ECG changes are visible after 30 to 60 seconds of hypoxia. After 8 to 10 seconds of blood flow,the myocardial cells are already cooler.Dressler syndrome, Pericarditis, and Heart failure are all complications of AMI; however, the most common is arrhythmia.A 23-year-old patient presents with severe chest pain that worsens with respiratory movements and with lying down. Which is the most appropriate intervention for thiscondition? Analgesics are the correct choice; this patient has pericarditis.A patient has been diagnosed with a pericardial effusion resulting in the presence of frank blood. Which condition is associated with a bloody effusion? Coagulationdefect, trauma, and aneurysms are all associated with bloody effusions.A patient has impaired blood flow from the left atrium to the left ventricle. Which valvular problems does this describe? Aortic Stenosis. Mitral stenosis is due to avalve that inhibits adequate blood flow from the left atrium to the left ventricle. Mitral regurgitation permits blood to flow backward from the ventricle to the atrium.Aortic blood flow problems occur from the left ventricle to the aorta.A patient has a loud pansystolic murmur that radiates to the back and axilla. Which valvular abnormality is this describing? Mitral regurgitation is characteristic ofthese findings. Aortic regurgitation is associated with a water hammer pulse. Aortic stenosis has a crescendo-decrescendo murmur. Mitral stenosis has a rumbling-decrescendo murmur.A patient has rheumatic fever. Which valve is most commonly affected? The mitral valve is the most commonly affected in rheumatic heart disease.A patient is diagnosed with inflammation of the endocardium by staphylococcus aureus. Which is the most likely medical diagnosis? Infective endocarditis is causedby an infection of staphylococcus aureus. Pericardial effusion is an accumulation of fluid in the pericardium. Chronic pericarditis is most commonly caused byradioactive exposure, rheumatoid arthritis, or uremia. Cardiomyopathy is a disease of the myocardium.
  7. 7. A patient experiences spinal cord damage following a motorcycle accident. Which type of shock would most likely result? Vasogenic shock results from an increase inparasympathetic nervous stimulation and a decrease in sympathetic nervous stimulation. Hypovolemic shock results from a decrease in blood volume due tohemorrhage. Anaphylactic shock is a hypersensitivity usually due to penicillin, latex, and food allergies. Septic shock is due to infection.Which characteristic is associated with hypertension? Hypertension is associated with positive family history, gender (men younger than 55 and women aftermenopause), black race (not Asian), high dietary sodium, glucose intolerance, cigarette smoking, obesity, heavy alcohol consumption, and low dietary intake ofminerals.A patient is being transferred from another medical facility with a diagnosis of acute myocardial infarction (AMI). Which symptom is typically observed with thepresences of an AMI? A patient may experience substernal chest pressure or pain, nausea, vomiting, abdominal pain, or indigestion. Fever, sweating, and cool andclammy skin are also typical. A cough is not considered a sign of an MI.Which enzyme is released by damaged myocardial muscle tissue? AST and ALT are liver enzymes that indicate damage to the liver cells. CK-MB, LDH, and TroponinI are all indicators of myocardial damage. Although LDH is also measured in liver function, it also has a purpose for AMI.The ductusarteriosus is the communication between the aorta and pulmonary artery. The foramen ovale is the flapped orifice that allows right-to-left shunting necessaryfor fetal circulation. The ligamentumvenosum is the result of the evolution of the ductusvenosus. The bulbuscordis is the conal portion of the ventricular septum thatseparates the aorta from the pulmonary artery.Which statement is correct regarding features of cardiac function of the newborn? The normal heart rate is 100 to 180. Cardiac output is high, and oxygen consumptiondoubles. The cardiovascular system is large compared with the body surface area.Congenital heart disease is the leading cause of death in the first year of life. There are 35 documented types of congenital heart disease. Thirty-five percent of deathscaused by congenital heart disease occur in the first year of life. The underlying cause is known in only 10% of cases.Poor feeding or poor sucking is often found in left ventricular failure and leads to failure to thrive. Right ventricular failure is representative of the remaining options.There are three major types of defects. An ostiumprimum defect is found low in the septum. An ostiumsecundum defect is an opening in the center of the septum and isthe most common. A sinus venosus defect is an opening that occurs high up in the atrial septum near the SVC-RA junction.The auscultation of a crescendo-decrescendo systolic ejection murmur heard during the routine physical examination of a child entering grade school is most likely aresult of: An atrial septal defect may have this presentation. Mitral valve prolapse usually is diagnosed later and not in childhood. It has an opening click. A VSD has aharsh, loud, holosystolic murmur and systolic thrill. Congestive heart failure may have changes in feeding, respirations, or lung sounds.Eisenmenger syndrome is reversal of the left-to-right shunt to right-to-left. This is the only option that will dump deoxygenated blood into systemic circulation andcause cyanosis, symptoms of this disorder.An infant born with a congenital heart defect experiences sudden onset of dyspnea, cyanosis, and restlessness. Which condition will be considered as the cause of thesesymptoms? A Tet spell is a hypoxic spell associated with the tetralogy of Fallot. A VSD is a component of the tetralogy of Fallot, but does not cause these spells on itsown. Onset of Eisenmenger syndrome is reversal of the shunt. Tricuspid atresia is another congenital defect. Atrial septal defects often go undetected until a routinephysical examination.The nasopharynx and oropharynx are the structures of the upper airway. The larynx divides the upper and lower airways. The trachea and bronchi are in the lowerairway.The right and left main bronchi enter the lungs at the hila. The trachea bifurcates at the carina and has supportive U-shaped cartilaginous rings. The goblet cells secretemucus.Ventilation is the mechanical movement of gas or air into and out of the lungs. Ventilation often is misnamed respiration. Respiration is the exchange of CO2 foroxygen. Circulation refers to actual blood flow and oxygen delivery. Alveolar ventilation refers to the amount of air delivered to the alveoli.Chemoreceptors monitor arterial blood indirectly by sensing changes in the pH of CSF. Irritant receptors are found in the epithelium of conducting airways. They aresensitive to noxious aerosols, gases, and particles. Stretch receptors are located in smooth muscle and are sensitive to increases in the size or volume of the lungs. Jreceptors are located near the capillaries in the alveolar septa. They are sensitive to increased capillary pressure.In zone 1, the alveolar pressure exceeds pulmonary arterial and venous pressures. Zone 2 is above the level of the left atrium. Zone 3 is at the base of the lung.Which of the following would shift the oxyhemoglobin dissociation curve to the left? Only hypocapnia would shift the curve to the left. The other options either haveno affect or result in a shift to the right.Ventilation, diffusion, and perfusion are the three steps involved in gas exchange in the lungs. The remaining options are not involved in the process of gas exchange.An acinus is made up of respiratory bronchioles, alveolar ducts, and alveoli. The other structures are related to the upper respiratory tract.The two major muscles of respiration are the diaphragm and the external intercostals. The sternocleidomastoid and the scalene are accessory muscles, and the trapeziushas no direct impact on respirations
  8. 8. The respiratory center in the brain stem controls respiration by transmitting impulses to the respiratory muscles, causing them to contract and relax. The respiratorycenter is composed of several groups of neurons: the dorsal respiratory group (DRG), the ventral respiratory group (VRG), the pneumotaxic center, and the apneusticcenter. The pattern of breathing can be influenced by emotion, pain, and disease.Inadequate alveolar ventilation in relation to metabolic demands correctly defines hypoventilation. Hyperpnea is rapid breathing with little to no expiratory pause.Orthopnea is difficulty breathing due to body position. Dyspnea is the feeling of not getting enough air.Cheyne-Stokes respirations are characterized by alternating periods of deep and shallow breathing. Apnea lasting from 15 to 60 seconds is followed by ventilations thatincrease in volume until a peak is reached; then ventilation (tidal volume) decreases again to apnea. Kussmaul respiration (hyperpnea) is characterized by a slightlyincreased ventilatory rate, very large tidal volumes, and no expiratory pause. Normal breathing (eupnea) is rhythmic and effortless with an occasional deeper breath, orsighs. A rapid ventilatory rate is referred to as tachypnea.The most common cause of pulmonary edema is left-sided heart disease. When the left ventricle fails, filling pressures on the left side of the heart increase. Inhalationof organic dusts can result in an allergic inflammatory response called extrinsic allergic alveolitis, or hypersensitivity pneumonitis. Bronchiolitis is a diffuse,inflammatory obstruction of the small airways or bronchioles. Emphysema is abnormal permanent enlargement of gas-exchange airways (acini) accompanied bydestruction of alveolar walls without obvious fibrosis.A patient has symmetrically dilated airways. Which type of bronchial dilation is this? Cylindrical indicates symmetrical dilation. Saccular is when the bronchi becomelarge and balloon like. Varicose is when constrictions and dilations destroy the bronchi. Bronchiectasis is the persistent abnormal dilation of the bronchi.Bronchiolitis is an inflammatory obstruction of small airways and bronchioles observed most commonly in children and is caused by a virus. It is seen in adults withchronic bronchitis.A client experiences an increased pressure in the chest cavity with resulting collapse of the right lung and is diagnosed with a secondary pneumothorax. This diagnosisis based on what criterion? The client experienced some type of chest trauma resulting in the symptoms. Secondary pneumothorax indicates there was trauma to thechest resulting in the collapse of the lung. A tension pneumothorax causes a deviation of the trachea. Spontaneous pneumothorax has no known cause. A primarypneumothorax results from the rupture of blebs.Which diagnosis finding is characteristically present when the parietal pleura is infected? Unique breath sound called a friction rub. Infection and inflammation of theparietal pleura (pleurodynia) cause sharp or stabbing pain usually localized to a portion of the chest wall, where a unique breath sound called a pleural friction rub maybe heard over the painful area. Clubbing is the selective bulbous enlargement of the end (distal segment) of a digit (finger or toe). Clubbing is commonly associatedwith diseases that cause chronic hypoxemia, such as bronchiectasis, cystic fibrosis, pulmonary fibrosis, lung abscess, and congenital heart disease. Respiratory failure isdefined as inadequate gas exchange such that PaO2≤50 mm Hg or PaCO2≥50 mm Hg with pH ≤7.25. Hemoptysis is the coughing up of blood or bloody secretions,usually as a result of infection or inflammation that damages the bronchi (bronchitis, bronchiectasis) or the lung parenchyma (pneumonia, tuberculosis, lung abscess).Which statement regarding chronic bronchitis is TRUE? There is hypersecretion of mucus. This mucus will hold on to bacteria. There is a chronic productive coughthat lasts for at least 3 months and 2 consecutive years. It is increased in smokers.A patient is born with a α-antitrypsin deficiency. Which of the following conditions will most likely manifest? Primary emphysema is the only option that involves a α-antitrypsin deficiency.Which pathogen is consistent associated with nosocomial pneumonia? Pseudomonas is commonly acquired in a hospital or nursing home. Streptococcus pneumonia,Mycoplasma pneumonia, Haemophilus influenza are community acquired.What is the best method for minimizing the spread of tuberculosis from person to person? Wearing a face mask. Tuberculosis is very contagious and is transmitted viaair droplet, so wearing a mask would be most appropriate. The other options have no effect on this form of transmission.A patient is diagnosed with an antidiuretic hormone-producing lung tumor. What is the most likely diagnosis? Small cell carcinomas are often associated with ectopichormone production, especially antidiuretic hormone. Squamous cell carcinoma, Adenocarcinoma, and Undifferentiated large cell carcinoma cancer types are notassociated with hormone production.Increased respiratory drive will not result in hypercapnia but rather hypocapnia. Disease of the medulla, Large airway obstruction, horacic cage abnormalities, andDepression of the respiratory center all result in hypercapnia.The amount, pH, size, and bacterial count are all influential in the development and affect the outcome of aspiration pneumonia. Protein content has not been identifiedas a factor that increases risk.What information will the nurse include when educating a client regarding their diagnosis of empyema? Empyema is the presence of pus in the pleural space and is acomplication of respiratory infection. Empyema occurs most commonly in older adults and children and usually develops as a complication of pneumonia. Breathsounds are decreased directly over the empyema. Diagnosis is made by chest radiographs, thoracentesis, and sputum culture.Which disorder can be the cause of pulmonary fibrosis? All the options, Acute respiratory distress syndrome (ARDS), Tuberculosis, Inhalation of excessive amountsof coal dust, and Rheumatoid arthritis, but upper respiratory infections can result in pulmonary fibrosis.An adult is diagnosed with a chronic cough resulting from a viral infection. What nursing intervention is appropriate for this client? Chronic cough is defined as coughthat has persisted for more than 3 weeks, although 7 or 8 weeks may be a more appropriate time frame because acute cough and bronchial hyper-reactivity can beprolonged in some cases of viral infection. In nonsmokers, chronic cough is commonly caused by GERD. In smokers, chronic bronchitis is the most common cause ofchronic cough, although lung cancer must always be considered. Acute cough is most commonly the result of upper respiratory infections or allergic rhinitis. A)
  9. 9. Encourage the client to return for treatment if the cough has not resolved in 8 weeks, B) Assess for a history of gastroesophageal reflux disease (GERD), C) Assess for ahistory of allergic rhinitisWhich client has an increased risk for developing a pulmonary embolus (PE)? A) The adult in traction for a fractured femur, B) The woman taking birth control pills,C) The teenager receiving intravenous chemotherapy, D) The man with a prothrombin gene mutation Risk factors for PE include conditions and disorders that promoteblood clotting as a result of venous stasis (immobilization, heart failure), hypercoagulability (inherited coagulation disorders, malignancy, hormone replacement, oralcontraceptives), and injuries to the endothelial cells that line the vessels (trauma, caustic intravenous infusions). Genetic risks include factor V Leiden, antithrombin II,protein S, protein C, and prothrombin gene mutations.Which medical condition places a client at high risk for developing chronic upper airway obstruction? Congenital malformation, Subglottic stenosis Infection, foreignbody aspiration, angioedema, and trauma are all causes of acute upper airway obstruction. Chronic airway obstruction is associated with congenital malformations,cartilaginous weakness, vocal cord paralysis, and subglottic stenosis.Which statement regarding hypocapnia is TRUE? Should be assessed for in clients experiencing severe anxiety, Results in respiratory alkalosis, the conditionconfirmed by a PaCO2 less than 36 mm Hg Hyperventilation is alveolar ventilation exceeding metabolic demands. The lungs remove CO2 faster than it is produced bycellular metabolism, resulting in decreased PaCO2, or hypocapnia (PaCO2 less than 36 mm Hg). Hypocapnia results in a respiratory alkalosis that also can interferewith tissue function. Increased respiratory rate or tidal volume can occur with severe anxiety, acute head injury, pain, and in response to conditions that causeinsufficient oxygenation of the blood. Hypoventilation.Which statement regarding stridor is supported by medical research? Expiratory stridor is also called a monophonic wheeze. Stridor is a harsh, vibratory sound ofvariable pitch due to turbulent flow through the partially obstructed airway. Inspiratory stridor is generated with obstruction of the extrathoracic airway (above thethoracic inlet). Expiratory stridor, or a monophonic wheeze, may be generated by an obstruction to the intrathoracic airway (the mid to lower trachea and centralbronchi). Biphasic stridor typically reflects obstruction at the glottis.Airway obstruction is most likely to occur in an infant. Airway obstruction occurs earlier in infants than in older children. This is due to their smaller airway andsmaller diameter. They also have more cartilage and collapse easily. A cough can be a sign of infection, foreign body, or obstruction.Infants of mothers younger than 20 years of age are more likely to die of SIDS. The peak age for SIDS is 3 to 4 months, and the incidence declines after that. There is ahigher frequency in winter months. Less prenatal care and poverty are predictive factors.Croup is an acute laryngotracheobronchitis and almost always occurs in children between 6 months and 5 years of age, with a peak incidence at 2 years of age. In 85%of cases, croup is caused by a virus, most commonly parainfluenza. The incidence of croup is higher in males. Approximately 15% of affected children have a strongfamily history of croup. Children between the ages of 6 months and 5 years of age are at greatest risk.Surfactant is a lipid-protein mix produced by type II cells. It is critical for maintaining alveolar expansion and allows for normal gas exchange. It lines the alveoli andreduces surface tension, preventing alveolar collapse at the end of each exhalation.Which medical condition places a client at a higher risk for developing chronic upper airway obstruction? Congenital malformation, Subglottic stenosis Infection,foreign body aspiration, angioedema, and trauma are all causes of acute upper airway obstruction. Chronic airway obstruction is associated with congenitalmalformations, cartilaginous weakness, vocal cord paralysis, and subglottic stenosis.Which childhood population is associated with a high risk for asthma? Asthma is the most prevalent chronic disease in childhood, affecting 10% of U.S. childrenbetween 5 and 17 years of age, with boys more often affected than girls. Populations most affected include black and Hispanic children, those living in an urban setting,ethnic minorities, and those of low socioeconomic status.Which symptom would be characteristic of cystic fibrosis (CF)? Meconium stool is present in newborns; there is no connection to CF. Persistent cough, Pneumonia,Barrel chest, Wheezing are symptoms associated with CF.Which statement regarding respiratory distress syndrome (RDS) of the newborn is TRUE? RDS occurs almost exclusively in premature infants, and the incidence hasincreased in the U.S. over the past two decades. RDS occurs in 50% to 60% of infants born at 29 weeks gestation and decreases significantly by 36 weeks. Infants ofdiabetic mothers and those with cesarean delivery (especially elective C-section) also are more likely to develop RDS. It is more common in boys than girls and morecommon in whites than non-whites. The major predisposing factor is birth prior to 36 weeks. There is increased incidence in American newborns. It is more frequentlyseen in infants of diabetic mothers. Birth by elective cesarean section increases risk.Which statement regarding obstructive sleep apnea syndrome (OSAS) is TRUE? Children between the ages of 3 and 6 years of age often show symptoms. It is a resultof partial or intermittent complete airway obstruction. Exposure to passive smoke is considered a risk factor for this disorder. OSAS is defined by partial or intermittentcomplete upper airway obstruction during sleep with disruption of normal ventilation and sleep patterns. Childhood OSAS is quite common, with an estimatedprevalence of 2% to 3% of middle school children and up to 13% of children between 3 and 6 years of age. In children, unlike adults, OSAS occurs equally among girlsand boys. Possible influences early in life may include passive smoke inhalation, socioeconomic status, and snoring.Anemia is generally defined as a reduction in the number or volume of circulating red blood cells (erythrocytes) or an alteration in hemoglobin. Technically, anemia isnot a disease but a symptom of any number of disorders. There are over 400 types of anemia, but many of them are rare.Generally, the origin of anemia is classified as either nutritional or non-nutritional. Anemias of a nutritional origin are those that stem from a deficiency of somenutrient, mainly iron, vitamin B12, or folic acid (folacin or folate); but they can also result from a deficiency of other nutrients, including vitamins B2, B6, C, A, D, E,and K; as well as zinc, copper, calcium, and protein. The lack of certain enzymes can also cause anemia. Non-nutritional causes are those that produce a decreaseddevelopment of the red blood cell (RBC) precursors, decreased erythropoiesis (erythrocyte formation), or an increase in the destruction of RBCs.
  10. 10. Anemia is frequently associated with scurvy and may be indicative of a folate deficiency (macrocytic) or an iron deficiency (hypochromic). Nevertheless, patients haveresponded well with just the addition of vitamin C alone, suggesting that there may be a role that ascorbate plays in the maintenance of normal pools of reduced folates.However, there is no real evidence to suggest that folate is ascorbate dependent. In the case of iron deficiency, though, it is known that adding vitamin C will increaseiron absorption.Anemias can be classified using two basic approaches: etiology (pathophysiology): the causes of erythrocyte and hemoglobin depletion morphology: the characteristic changes in the erythrocytes red blood cells (RBCs), size, shape, and colorAn etiologic classification is based on the various conditions that can result from any of the physiologic changes and helps determine direction for planning care. Amorphologic classification provides an orderly method for ruling out certain diagnoses when establishing a cause for a particular anemia.Such morphologic changes in the red blood cell are described in this manner: Cell size: (Terms that refer to cellular size end with "cytic".) Cell shape:normocytes (normal) poikilocytes (irregularly-shaped cells)microcytes (smaller than normal) spherocytes (globular cells)macrocytes (larger than normal) drepanocytes (sickle cells)anisocytes (various sizes) Cell color: (generally refers to the staining characteristics which reflects the hemoglobin concentration. Terms that describe hemoglobin content end with "chromic".)normochromic (sufficient or normal amounts of hemoglobin)hyperchromic (containing an unusually high concentration of hemoglobin in its cytoplasm)hypochromic (containing an abnormally low concentration of hemoglobin)These changes produce the following categories of anemias: Macrocytic-normochromic anemias (pernicious and folate-deficiency) Microcytic-hypochromic anemias (iron-deficiency, sideroblastic, thalassemia) Normocytic-normochromic anemias (aplastic, posthemorrhagic, hemolytic, chronic disease, sickle cell)Macrocytic-normochromic anemia, also known as megaloblastic anemia, produces large, abnormally shaped erythrocytes but normal hemoglobin concentrations. Theunusually large stem cells (megaloblasts) in the bone marrow mature into abnormally large erythrocytes (macrocytes) in the circulation. Megaloblastic stem cells arelarger at all maturational stages than normal stem cells (normoblasts). In addition, the nucleus of the megaloblast is unusually small in relation to the size of the cell. Asthe cell matures and begins to synthesize hemoglobin, chromatin in the nucleus fails to clump normally, although the hemoglobin content remains normal. DefectiveDNA synthesis, caused by deficiencies of vitamin B12 or folate, produces a pattern of ineffective erythropoiesis (cell formation), causing premature cell death withreduced numbers of mature erythrocytes. It is unknown why such a deficiency would cause this outcome, but suggested mechanisms include a delay in nuclearmaturation and an imbalance in the normal distribution of RNA and DNA. Nuclear functions or DNA replication and cell division are blocked or delayed. However,RNA and protein synthesis, both cytoplasmic functions proceed normally. The imbalance in the RNA/DNA ratio causes derangement of cell growth.Microcytic-hypochromic anemia produces small, abnormally small erythrocytes and reduced hemoglobin concentrations. However, hypochromia can occur even incells of normal size. This type of anemia results from a variety of conditions that are caused by disorders of iron metabolism, porphyrin and heme synthesis, or globinsynthesis.Normocytic-normochromic anemia produces a destruction or depletion of normal or mature erythrocytes. Although the erythrocytes are relatively normal in size andin hemoglobin content, they are insufficient in number. This type does not share any common cause, pathologic mechanism, or morphologic characteristics and is lesscommon than the others. The five distinct anemic conditions exemplify the diversity of this classification. Aplastic anemia (caused from depressed stem cell proliferation resulting in bone marrow aplasia) Posthemorrhagic anemia (caused from an abnormal amount of blood loss) Hemolytic anemia (premature destruction [lysis] of mature erythrocytes in the circulation)
  11. 11. Anemia of chronic disease (chronic infection or inflammation or malignancy causes an abnormally increased demand for new erythrocytes) Sickle cell anemia (congenital dysfunction of hemoglobin synthesis causing abnormal cell shapes)Data used to identify anemia types include the erythrocyte indicators: mean corpuscular volume (MCV), measures the average erythrocyte volume mean corpuscular hemoglobin (MCH), measures the average amount of hemoglobin per erythrocyte mean corpuscular hemoglobin concentration (MCHC), measures the average concentration of hemoglobin in erythrocytes. (See more under Lab Tests.)Anemias associated with decreased RBCs can occur for any number of reasons. Some anemias arise from failure or inability of the bone marrow to synthesize RBCsproperly. Others occur because the body cannot synthesize or absorb a specific component necessary for RBC production. Such anemias resulting from a decreasedproduction of RBCs include iron deficiency anemia, Vitamin B12 (pernicious) anemia, folic acid deficiency anemia, and aplastic anemia. Of those suffering fromanemia, 20% are women and 50% are children.Anemia is sometimes the first detectable sign of arthritis, infection, or certain major illnesses, including cancer. Drug use, hormonal disorders, chronic inflammation inthe body, surgery, infections, peptic ulcers, hemorrhoids, diverticular disease, heavy menstrual bleeding, repeated pregnancies, liver damage, thyroid disorders,rheumatoid arthritis, bone marrow disease, and dietary deficiencies can all lead to anemia. There are also a number of hereditary disorders that cause anemia, especiallysickle cell disease and thalassemia.According to the Iron Institute, who gathered definitions from medical dictionairies and encyclopedias as well as the internet, anemia has a wide variety of definitions.Even though all of them are correct to some extent, none of them is a complete definition. The following are just a few which will explain why it is so difficult toumbrella over 400 anemias into one convenient description. Anemia is: a condition in which the number of RBCs is below normal a reduction in total circulating RBC mass, diagnosed by a decrease in hemoglobin concentration a hemoglobin level below 12 g/dl any condition resulting from a significant decrease in the total body erythrocyte mass a decrease in the circulating RBC mass and a corresponding decrease in the oxygen-carrying capacity of the blood a decreased ability of RBCs to provide adequate oxygen supplies to body tissues a reduction in the hemoglobin concentration to below 13.5 g/dl in an adult male and to below 11.5 g/dl in an adult female any condition characterized by an abnormal decrease in the body’s total RBC mass a condition in which either RBCs or the amount of hemoglobin (oxygen-carrying protein) in the RBC is low a condition in which a person has inadequate amounts of iron to meet body demands a decrease in the amount of RBCs in the blood caused by having too little iron having fewer than the normal number of RBCs or less hemoglobin than normal in the blood decreases in numbers of RBCs or hemoglobin content caused by blood loss, deficient erythropoiesis, excessive hemolysis, or a combination of these changes a blood disorder that results from a shortage of hemoglobin in the RBCs, the disk-shaped cells that carry oxygen to all parts of the body an abnormal reduction in RBCs a condition when the amount of RBCs or hemoglobin becomes low, causing the tissues of the body to be deprived of oxygen-rich blood a reduction in the number of RBCs in the body a condition in which the blood is low on health RBCs the reduction of circulating RBCs per cubic millimeter, the amount of hemoglobin per 100 ml, or the volume of packed red cells per 100 ml of blood
  12. 12. a condition in which hemoglobin levels are too low to provide for the oxygen demands of the body decreased or absent iron stores; decreased serum ferritin; low serum iron; low transferrin saturation; increased iron-binding capacity hypochromic, microcytic, erythrocytes a decreased amount of hemoglobin in the blood a reduction in hemoglobin below normal hemoglobinLiterally, ―anemia‖ means without blood! This is also an absurd definition because people cannot live without blood, but they can live with anemia.Symptoms of anemia often go unrecognized. The first signs of its development may be a loss of appetite, constipation, headaches, noises in the ears, irritability, and/ordifficulty concentrating or with memory. Established anemia produces such symptoms as weakness, fatigue, coldness of the extremeties, depression, dizziness, overallpallor (pale complexion), pale and brittle nails (lack of iron), pale lips and eyelids, pallor in the palms of the hands, soreness in the mouth, restless leg syndrome, and acessation of menstruation and/or a loss of libido. Pallor results when blood flow is diverted away from the skin, or other areas, in order to meet the more critical needsof the body, as the brain and heart.These symptoms are caused by the inability of anemic blood to supply body tissues with enough oxygen. Activity intolerance is a common problem since physicalactivity increases the demand for oxygen. If there are not enough oxygen-circulating erythrocytes to provide sufficient oxygen, individuals become physically weak andunable to engage in normal physical activity without experiencing profound fatigue. In very advanced cases, swelling of the ankles and other evidence of heart failuremay appear.Although pallor of the skin is a sign of anemia, it is not the most reliable sign because many other factors can affect complexion and skin color. When pallor of the skin,nail beds, and conjunctiva are all noticed, the cause is likely anemia. Jaundice of the skin and sclera can occur as a result of hemolysis and the release of bilirubin intothe blood stream where it eventually finds its way into the skin and mucous membranes. Bleeding under the skin and bruises in response to the slightest trauma oftenare present in anemic and leukemic patients. A bluish tint to the skin (cyanosis) can indicate hypoxia caused by inadequate numbers of oxygen-carrying erythrocytes.Swollen and bleeding gums can occur as a result of nutritional deficiencies and inadequate blood supply to mucous membranes. Breakdown of the oral mucosa canfurther aggravate anemia by making chewing, tongue movements, and swallowing difficult.Bleeding into the joints is not unusual in certain kinds of anemia, especially sickle cell disease. Patients may report joint pain or they may be observed moving moreslowly than usual and with apparent discomfort. In addition, the joints appear red and swollen.Until recently, RLS (restless leg syndrome) was basically ignored as being a symptom of anything despite it being a revalent disorder affecting up to 15% of adultpopulations. The syndrome is characterized by a strong urge to move the extremeties that usually becomes worse at night, peaking somewhere in the middle of thenight. While much of the clinical intervention has focused on the dopaminergic system (dopamine is a chemical synthesized by the adrenals), there is a growing body ofevidence that suggests an iron deficiency cause. High dose, intravenous iron therapy brought on complete relief of symptoms in 21 out of 22 RLS patients for periods ofthree to nine months, even though the majority had normal iron levels prior to treatment.When anemia is severe or sudden in onset, peripheral blood vessels constrict so as to direct available blood flow chiefly to the vital organs. A number of systemicsymptoms result from this lifesaving maneuver. Kidneys: Decreased blood flow is sensed by the kidneys, causing the renal renin-angiotensin response to activate, resulting in salt and water retention. Skin: Decreased oxygen delivery to the skin results in impaired healing and loss of elasticity. Hair: Decreased oxygen delivery to the hair results in thinning and early graying. Nervous system: If anemia, that is, poor oxygen delivery, is because of vitamin B12 deficiency, the nervous system will be affected as myelin degeneration may occur with loss of nerve fibers in the spinal cord. Numbness (paresthesias), gait disturbances, extreme weakness, spasticity, and reflex abnormalities can result. Gastrointestinal tract: Decreased oxygen supply to the gastrointestinal tract often produces abdominal pain, nausea, vomiting, and anorexia. Other areas: The skin, mucous membranes, lips, nailbeds, and conjunctiva become either pale as a result of reduced hemoglobin concentration, or yellowish as a result of the presence of products of red blood cell breakdown (hemolysis). Low grade fever (less than 101°F) occurs in some anemic individuals and may be the result of leukocyte pyrogens being released from ischemic tissues.Some types of anemia include the following: Achrestic anemia is a megaloblastic type, morphologically resembling pernicious anemia but with multiple other causes. Aplastic anemia is a form generally unresponsive to specific anti-anemia therapy and is often accompanied by granulocytopenia (a sudden drop in the production of leukocytes) and thrombocytopenia (a decrease in the number of platelets in circulating blood), in which the bone marrow may not necessarily
  13. 13. be lacking cells or a normal cellular structure (acellular) but still fails to produce adequate numbers of blood elements. The term actually is all-inclusive, generally encompassing several clinical syndromes. Autoimmune hemolytic anemia (AIHA) is a general term used to cover a large group of anemias involving auto-antibodies against red cell antigens. Cooleys anemia is the homozygous form of beta-thalassemia. Deficiency anemia refers to a nutritional deficiency that causes anemia. Drug-induced immune hemolytic anemia is, as the name suggests, an immune hemolytic anemia caused by drugs, classified by such mechanisms as:the penicillin type, in which the drug, acting as a hapten is bound to the red cell membrane which induces the formation of specific antibodiesthe methyldopa type, in which the drug, possibly by inhibition of suppressor T cells, indicates the formation of anti-Rh antibodies, andthestibophen or "innocent bystander" type, in which the circulating drug-antibody immune complexes binds nonspecifically to red cells. Erythroblastic anemia (see Cooley’s anemia). Hemolytic anemia is caused by a shortened survival of mature erythrocytes and the ability of bone marrow to compensate for their decreased life span. It may be hereditary or acquired and usually results from an infection or chemotherapy, or occurs as part of an autoimmune process. Hypochromic anemia occurs when there is a decrease in hemoglobin that is proportionately much greater than the decrease in the number of erythrocytes. Hypoplastic anemia is the result of the incapacity of blood-forming organs. Such anemias as Diamond-Blackfan, Pearson’s, transient,erythroblastopenia of childhood (TEC), and Fanconi’s are classified under hypoplastic anemia. Hypoplastic congenital anemia, also called erythrogenesisimperfecta and Fanconis syndrome, is an idiopathic progressive form occurring in the first year of life and without leukopenia and thrombocytopenia. It is unresponsive to hematinics (an agent that improves the quality of the blood) and requires multiple blood transfusions to sustain life. Iron-deficiency anemia is characterized by low or absent iron stores, low serum iron concentration, low transferrin saturation, elevated transferrin (total iron-binding capacity), low hemoglobin concentration or hematocrit, and hypochromic and microcytic red blood cells. Its frequent occurrence in children is usually the result of prolonged milk feeding without the provision of a variety of foods or supplemental iron. Lederers anemia is an acute hemolytic form of short duration and unknown etiology. Macrocytic anemia results when the erythrocytes become much larger than normal. Mediterranean anemia (see Cooley’s anemia) Megaloblastic anemia is characterized by the presence of megaloblasts in the bone marrow. Megaloblasts are large, nucleated, immature progenitors of an abnormal erythrocytes and form in certain types of anemia. These cells are irregular in shape and size but contain normal concentrations of hemoglobin and the numbers are below normal. This reaction involves the abnormal production of red cells, white cells, and platelets. There are two types of megoblasticanemias and both are the result of a deficiency (folic acid or B12). Microcytic anemia is characterized by a decrease in size of erythrocytes. Myelopathic, or myelophthisic, anemia is caused by the destruction or crowding out of hematopoietic tissues by space-occupying lesions. (Hematopoietic pertains to or affecting the formation of blood cells.) Normochromic anemia occurs despite the hemoglobin content of the red blood cells, as measured by the MCHC (mean corpuscular hemoglobin concentration), is still within the normal range. Normocytic anemia is characterized by proportionate decreases in hemoglobin, packed red cell volume, and the number of erythrocytes per cubic millimeter of blood. Nutritional anemia, also known as "deficiency anemia", is caused by a deficiency of an essential substance in the diet, and may be caused by poor dietary intake or by malabsorption. Pernicious anemia is a serious form that results from a lack of vitamin B12, generally because of a decreased secretion by the gastric mucosa of IF (intrinsic factor) essential to the formation of erythrocytes and the absorption of vitamin B12. This condition may be secondary to an illness or idiopathic (formed from unknown causes). Treatment consists of regular, lifetime administrations of the vitamin.
  14. 14. Sickle cell anemia, sometimes called sickle cell disease, is a genetically determined defect of hemoglobin synthesis associated with poor physical development and skeletal anomalies. Spur-cell anemia occurs when the red cells have a bizarre spiculated shape and are destroyed prematurely, primarily in the spleen. It is an acquired form occuring in severe liver disease and represents an abnormality in the cholesterol content of the red cell membrane. Von Jaksch’s anemia, also known as pseudoleukemicainfantum, is an anemic leukemia of infants and probably not a distinct disease. It is a syndrome caused by many factors: malnutrition, chronic infection, malabsorption, or other conditions. There seems to be some developmental basis for the inability of these babies to react to infectious processes in a normal manner. This disease follows, or is associated with, some severe nutritional or infectious disease and is characterized by anemia of increasing severity, splenomegaly and myeloid leucocytosis, together with the symptoms of the underlying disease. It is possible that symptoms of severe malnutrition ordinarily supposed to be the cause of the anemia, may really be the earlier symptoms of the disease itself, as an entity caused by developmental defect in the spleen and red bone marrow. It was once considered to be a specific entity in children under the age of three.There are three cardinal Red Cell Measurements that determine anemia: RBCs (red blood cell count), hemoglobin levels, and hematocrit levels. At first glance, it mayseem that these three are redundant since low levels of all three indicate anemia when levels fall and a correction when they rise. While all three tend to run parallel,they are not always straight. For example, in one type of anemia, RBCs may be lower than would be expected for observed levels of hemoglobin. This happens inmacrocticanemias. To further distinguish problems, three calculated Red Cell Indices have been devised. These are MCV (mean corpuscular volume), MCH (meancorpuscular hemoglobin), and MCHC (mean corpuscular hemoglobin concentration).Iron Deficiency Anemia TestingThe most common tests measure the number and size of the red blood cells and the cells hemoglobin content. A sensitive test that will detect a developing irondeficiency before it is full-blown,it measures the amount of transferrin in the blood and the amount of iron it is carrying. At the very beginning of an iron deficiency,before these levels fall, the transferrin concentration rises for a short time. Other tests measure iron stores.Iron stores are measured directly (by bone marrow biopsy) or indirectly (by blood tests that measure serum ferritin, transferrin saturation, or total iron-binding capacity).A sensitive indicator of heme synthesis is the amount of free erythrocyte protoporphyrin (FEP) within erythrocytes. However, the results of these tests can bemisleading because of such complicating factors as infection, pneumonia, a blood transfusion, or iron supplements. Bone marrow studies may reveal depleted or absentiron stores (done by staining) and normoblastic hyperplasia. Diagnosis must rule out such other forms of anemia as that from thalassemia minor, malignancy, andchronic inflammatory, hepatic and renal disease.Characterisitic blood study results that could indicate anemia include the following: low hemoglobin levels (males, <12g/100ml; females, <10g/100ml) low hematocrit levels (males, <47ml/100ml; females, <42ml/100ml) low serum iron levels, with high binding capacity low serum ferritin levels low RBC count, with microcytic and hypochromic cells (in early stages, RBC count may be normal except in infants and children) decreased MCVRBC count: Normally, there are 4.7 million to 6.1 million red cells per microliter of adult male blood. For females, the normal range is 4.2-5.4 million/µl. The problemwith using only this test for anemia is that all red cells are not equal. In the various types of anemia and other hematologic conditions, the size and weight of each redcell can vary markedly. Sometimes, the number of cells is normal; but the mass of each cell may be abnormally low, indicating anemia despite a normal RBC count.Hemoglobin concentration: It is very difficult to measure the concentration in individual red cells, so the first step is to ―pop‖ all the red cells and let the hemoglobinflow out into the blood sample where it becomes evenly distributed in the plasma. This process is called ―hemolysis‖ (hemo meaning blood and lysis meaningdestruction). Since hemoglobin is a colored substance, its concentration can easily be measured by shining a light through the thickness of the specimen to determinehow much light is blocked. This process is called ―colorimetry‖. The lower the concentration of the colored substance, the more light shines through. The only problemis that, when hemoglobin is released, it goes berserk chemically and starts to break down, losing some of its light-absorbing qualities. To offset this problem, the sampleis chemically transformed into a substance called cyanmethemoglobin. It is this solution that is analyzed by colorimetry; and, after a few mathematical calculations, theoriginal concentration of hemoglobin can be determined. For males, the normal level is 14-18 grams per deciliter of blood (a deciliter is 1/10 of a liter) For females, the normal level is 12-16 g/dLHowever, most practitioners use the lower figure of 12 for both men and women when giving a diagnosis of anemia. But not every doctor does this. Some doctors allowelderly people a lower level without initiating further diagnostic workups. Since anemia is common in the elderly, this practice needs to be revised.Hematocrit (PCV): The hematocrit is defined as the fraction of the volume of whole blood occupied by the red blood cells and is a measurement of volume, not mass.Another name is Packed Cell Volume (PCV), expressed in a percentage of the total blood volume. To determine this, a clinician spins a volume of blood in a centrifugeto separate the red blood cells from the plasma. Low values indicate a reduced number of red blood cells, and thus anemia. Normal levels are as follows:
  15. 15. Adult men: 40%-54% Adult women: 37%-47% Children ages 2-5: 34% Children ages 6-12: 37%MCV: Mean corpuscular volume is a direct or calculated measure to determine the average size of a red blood cell. This is calculated by dividing the hematocrit by theRBC count and multiplying by a unit conversion factor. Such a measure helps to classify the type of anemia. The reference range for MCV is 80-94 femtoliters (afemtoliter is one quadrillionth of a liter), commonly abbreviated 80-94 fL. In iron deficiency anemia, the red blood cells are smaller than average (microcytic). In folateand B12 deficiencies, the red blood cells are larger than average (macrocytic). One in which the MCV falls within the reference range is a normocytic anemia.MCH: Mean corpuscular hemoglobin is defined as the average mass of hemoglobin in each red cell. This is calculated by dividing the hemoglobin concentration ofwhole blood by the RBC count and multiplying by a unit conversion factor. The reference range for MCH is 27-31 picograms (a picogram is one trillionth of a gram),commonly abbreviated 27-31 pg. This is technically not a very important red cell index because it tends to parallel the MCV.MCHC: Mean corpuscular hemoglobin concentration is the average concentration of hemoglobin in the red cells. It is calculated by dividing the whole bloodhemoglobin concentration by the hematocrit and applying a unit conversion factor. The reference range is 32 to 36 grams per deciliter, abbreviated 32-36 g/dL. Whenthe level falls below the normal range, it is classified as hypochromic anemia (very rare). If the level is higher than the normal range, it is hyperchromic anemia and ifthe MCHC is within the reference range, it is called normochromic anemia.Sickle Cell TestingInfant screening: It is done with blood samples collected at birth from the umbelical cord or from a heel prick. However, testing is not usually done before the child iseighteen weeks old unless there is a high risk for sickle cell disease or anemia. Blood samples are analyzed to see what kinds of hemoglobin the infant is producing. Ifabnormal hemoglobin is found, the physician will want to have the DNA of the sample analyzed for a genetic diagnosis. Often, the testing procedure is repeated --starting with a new blood sample -- to make sure that the results are accurate. If commercial laboratories do the testing, the procedures they generally use are as follows: high performance liquid chromatography (often this is the testing method used first to identify which type of hemoglobin is present. These results will be confirmed with the hemoglobin electrophoresis method) isoelectric focusing (identifies hemoglobin bands by their migration in an electric field and abnormal specimens are presumed positive for sickle cell disease and will be suject to further testing) hemoglobin electrophoresisIf the sickle cell trait is evident, a CBC (complete blood count) will show the following: RBCs (red blood cells) will be low and WBC (white blood cells) will be elevated. Platelet counts and hemoglobin may be low or normal. Erythrocyte sedimentation rate is decreased. Serum iron is increased. RBC survival time is decreased. Reticulocyte count is increased.Hemoglobin electrophoresis: Electrophoresis tests were the first technique used in the discovery of abnormal hemoglobin in those with sickle cell disease. Testingvariations of this type was developed by Dr. Linus Pauling and still widely used today to diagnose sickle cell disease. This test is not only able to determine if a patienthas the disease or the trait, but it can also indicate if the person has such related blood disorders as thalassemia, hemoglobin C, or hemoglobin D. Electrophoresis testingused to be very time-consuming and expensive, although it can usually be done now in under an hour. However, improvements have made it quicker, simpler, lesscostly, and very reliable.The electrophoresis equipment consists of two tanks with a strip of a solid material stretched between them. The solid material may be made from cellulose acetate andlooks like a strip of paper; or it can consist of a thin layer of agarose, a seaweed extract, placed on a plastic sheet. Electrodes are placed into each tank and the tanksfilled with a buffered solution. An electrical circuit is formed that conducts current from one electrode, through a buffer, across the solid material, into the other tank ofbuffer, and finally into the second electrode.If a solution of hemoglobin is placed on the solid strip and a voltage applied to the electrode, the hemoglobin molecules will move toward the negative electrode. Whenthe blood of a person with sickle-cell anemia is analyzed next to that of a normal individual, the hemoglobins are seen to migrate to different locations. The sickle cellhemoglobin has a greater positive charge than normal hemoglobin and will move toward the negative electrode at a faster rate. The blood of a person with sickle celltrait has two different hemoglobins: one moves like the normal molecule while the other migrates like that of a person with sickle cell anemia.
  16. 16. TechniCon system: It is an automated test. A drop of blood is put into a little cup and mixed with a special chemical formula. The machine reads the solution bymaking a tracing on graph paper. If the person has sickle cell disease or sickle cell trait, the line makes a tall peak. If the test comes out positive, a second test can bedone to indicate whether the person has the disease or the trait. In the second test, the height of the peak depends on how much sickle hemoglobin there is. The peakobserved for a person with sickle cell disease will be twice as high as the peak for someone with sickle cell trait.Transcranial Doppler imager: It is an ultrasound device which allows doctors to try to prevent strokes in children by using this test to identify which children have thegreatest risk. It has been found that changes occur in the brain blood vessels of many children with sickle cell disease. The arteries gradually narrow, making them morelikely to become clogged, causing the blood cells to sickle. Such plugs of blood cells could cut off blood flow to parts of the brain, resulting in death of brain tissue (astroke). The Doppler imager shows the narrowed areas that are potential trouble spots. This allows the doctor to be better able to identify patients who are at a greaterrisk for strokes and can treat them accordingly.Strokes are the most serious side effect among children with sickle cell disease. Studies have found up to 17% of sickle cell patients have strokes which occur mostoften in childhood and adolescence. The result may be learning disabilities, paralysis, or even death.Tests not reliable: Two unreliable tests are the metabisulfite test and the solubility test. They are not sensitive enough to distinguish between sickle cell disease andsickle cell trait.Metabisulfite test: Although the sodium metabisulfite test is fairly simple and rather inexpensive to perform, it is not reliable. A drop of blood is put onto a glass slidewith a drop of the chemical sodium metabisulfite. The slide is covered with a coverslip and sealed with Vaseline to keep out oxygen. After a short time, the technicianchecks for sickling. In addition to being unable to distinguish between sickle cell disease and sickle cell trait, this test may also produce false negatives and falsepositives, as well as being unreliable in testing newborns.Solubility test: The sickledex is another unreliable method used in large-scale testing programs. A drop of blood is put in a test tube along with several chemicals thatcause the outer membrane of the red blood cells to burst, allowing their contents to leak out (a process known as hemolysis). Normal hemoglobin dissolves readily inthe solution in the test tube, but hemoglobin S is less soluble. Therefore, if the fluid turns cloudy after a short time, it means sickle cells are present. If the fluid is clear,the blood is normal. Like the sodium metabisulfite test, major disadvantages of the Sickledex test are: it cannot distinguish between the sickle cell disease and the sicklecell trait; and, it is expensive and unreliable for newborns.The dithionite test: It is a variation of the sickledex test. It uses the same chemicals as the Sickledex test, but everything is automated. Since the test tube readings aredone by machine, the process is faster and less costly; but, like the other two tests, it cannot be used to screen newborns. Even babies with two sickle cell genes have toolittle HbS in their blood to give a positive reading. During fetal development and for a short time after birth, the infants blood contains mainly fetal hemoglobin (HbF),in which two alpha chains are combined with two gamma globin chains instead of two beta chains.Hemolytic Anemia TestingOne or more lab tests are generated in order to distinguish between anemias caused by lowered cell production (hyporegenerativeanemias) or by shortened red cell lifespan (hemolytic anemias). This distinction is made through one or more of the following means.Reticulocyte count: This is the most important test in the initial classification of a normocytic anemia. Hemolytic anemias are usually normocytic normochromic,meaning that the average red cell is of normal size and concentration of hemoglobin, which is not surprising since production is completely normal, too. The problem isthat something is causing these normal red cells to be destroyed much faster than they can be replaced. The result is that the number of immature reticulocytes in theblood rises severalfold above the normal level of less than 1.5%. In fact, in a severe case of hemolytic anemia, the retic count may be as high as 20%. This test is highlyreliable, inexpensive, and easily done in even the most primitive labs. Despite this, many physicians fail to make use of it.Blood smear examination: In some types of hemolytic anemia, the shape of the red cells is abnormal. Their appearance can easily be assessed through a peripheralsmear examination. A drop of blood is placed on a glass microscope slide, and the edge of another slide is drawn into the drop. Just before the drop has spread over theinterface between the edge of the second slide and the surface of the first slide, the second slide is smartly scraped over the length of the first slide. The result is a flame-shaped smear on the first slide. The end of the smear at which the blood was first dropped is too thick to examine; but, out toward the feathered edge at the oppositeend, the smear is just thin enough to allow the cells to be seen. The technique of creating smears is actually quite difficult, and it takes quite a bit of practice bytechnicians before they are considered proficient. Since nothing can be seen on an unstained smear, one of the Romanowsky stains (usually Wright) is employed tomake the cells visible. Reticuloyces cannot be distinguished from other red cells on the Wright stain, however; so the next step is to examine them microscopically attwo levels of magnification (100X and 1000X). The lower power is for screening the smear for rare abnormal cells and the higher one is for discerning the details of thecells. With rare exception, the only people truly qualified to evaluate a blood smear thoroughly are hematologists and laboratorians.Serum bilirubin level: Because of the accelerated destruction of red cells in hemolytic anemia, heme is broken down more rapidly. Unconjugated (indirect) bilirubinaccumulates in the plasma because the liver, that normally collects, conjugates, and excretes it, is overwhelmed. The level of bilirubin is measured in serum with a verysimple, routine test. If the level is high enough (about 2 mg/dL), clinical jaundice is usually noticed. In hemolytic anemias where the liver function is normal, the serumbilirubin rarely exceeds 7 mg/dL. Much higher levels (up to 50 mg/dL) may be observed in patients with diseases of the liver or bile ducts. Because jaundice is seen inthese diseases, as well as in hemolytic anemias, the doctor is interested in knowing the relative proportions of conjugated (direct) and unconjugated bilirubin in theserum. In liver and biliary tract disease, there is more conjugated than unconjugated bilirubin in the serum. In hemolytic anemia, the reverse is true. Thus, the serumbilirubin test typically yields three results: total, indirect, and direct bilirubin.Urine urobilinogen: This is part of the routine urinalysis dipstick test. In the hemolytic state, the liver churns out conjugated bilirubin at full tilt. Some of this iseventually converted to urobilinogen in bowel bacteria, reabsorbed, and excreted in the urine, where increased amounts are detected in the dipstick test.Serum haptoglobin level: Because of the sloppy spilling of hemoglobin by RES (reticuloendothelial system) while it disposes of red cells, in times of brisk hemolysis,more hemoglobin is spilled. This is quickly turned into haptoglobin and cleared from the plasma by the RES. If hemolysis is rapid enough, all of the haptoglobin is usedup and undetectable in the serum by a lab test. Therefore, the serum haptoglobin can be used as a measure of hemolysis -– the lower the serum haptoglobin, the worsethe hemolysis.
  17. 17. Urine hemoglobin: Normally, the kidneys do such a good job in keeping red cells from falling out of the blood vessels that no hemoglobin is detectable in the urine.The routine dipstick urinalysis can detect any hemoglobin that escapes into the urine in the course of brisk hemolysis. A positive hemoglobin test by dipstick is not anindication of hemoglobinuria however, since any of a number of conditions can cause blood in the urine, including simple urinary tract infections.Pernicious Anemia TestingBlood results that suggest pernicious anemia include the following: decreased hemoglobin (4 to 5 g/100ml) and decreased RBCs; increased mean corpuscular volume (MCV>120), mainly because larger-than-normal RBCs each contain increased amounts of hemoglobin, meaning corpuscular hemoglobin concentration is also increased; possible low WBC, low platelet counts, and large, malformed platelets; serum vitamin B12 assay levels < 0.1 mcg/ml; elevated serum LDH.Bone marrow aspiration reveals erythroid hyperplasia (crowded red bone marrow) with an increased number of megaloblasts and only a few normally developingRBCs. Gastric analysis shows the absence of free hydrochloric acid after histamine or pentagastrin injection.Schilling test is the definitive test for pernicious anemia. In this test, the patient fasts for 12 hours and then receives a small oral dose (0.5 to 2 mcg) of radioactivevitamin B12. Two hours later, a larger dose (1 mg) of nonradioactive vitamin B12 is given IM, as a parenteral flush; and the radioactivity of a 24-hour urine specimen ismeasured. About 7% of the radioactive B12 dose is excreted in the first 24 hours; but those with pernicious anemia will excrete less than 3%, leaving the remainderunabsorbed and it passes into the stool. When the Schilling test is repeated with IF added, the test shows normal excretion of vitamin B12. Important serologic findingsmay include IF antibodies and antiparietal cell antibodies.Thalassemia TestingTo differentiate between iron deficiency and thalassemia, RBC indices can be helpful. The hemoglobin concentration will generally be lower in iron deficiency, but thedistinguishing factors will be in elevated HbA and HbF. These will be elevated in beta thalassemia but normal or decreased in alpha thalassemia or iron deficiencyanemia. The Mentzer Index was developed to help distinguish these two anemias. It is calculated by dividing the RBC count into the MCV. If the quotient is less than13, thalassemia is more likely; but if the quotient is greater than 13, it is more likely to indicate iron deficiency. Thalassemia major: RBCs and hemoglobin are decreased; reticulocytes, bilirubin, and urinary and fecal urobilinogen are elevated; low serum folate level, indicating increased folate utilization by the hypertrophied bone marrow. Peripheral blood smear reveals target cells (extremely thin and fragile RBCs),microcytes, pale nucleated RBCs, and marked anisocytosis. Skull and skeletal x-rays show a thinning and widening of the marrow space in the skull and long bones, possible granular appearance in the bones of the skull and vertebrae, possible areas of osteoporosis in the long bones, and deformities (rectangular or biconvex) of the phalanges. Quantitative hemoglobin studies show a significant rise in Hb F and a slight increase in Hb A2. Diagnosis must rule out iron deficiency anemia, which also produces slightly lowered hemoglobin (hypochromia) and notably small (microcytic) RBCs. Thalassemia intermedia: RBCs are hypochromic and microcytic, but the anemia is less severe than that in thalassemia major. Thalassemia minor: RBCs are slightly hypochromic and microcytic. Quantitative hemoglobin studies show a significant increase in HbA levels and a moderate rise in HbF levels. Effects of chronic hemolysis 1. Anemia. Pretty much self-explanatory 2. Jaundice, due to rapid heme turnover and subsequent generation of bilirubin 3. Cholelithiasis. It has been classically taught that sickle cell patients are prone to the formation of calcium bilirubinate gallstones due to excess bilirubin secretion into the hepatobiliary tree. 4. Aplastic crisis. Many of us have brief episodes of marrow aplasia as a result of common viral infections. With a normal erythrocyte life span of 120 days, no anemia results from an unnoticed marrow shut-down of a few days. However, the sickle cell patients, with their markedly abbreviated rbc life span, can have a precipitous fall in hematocrit (and retic count) under such conditions. This may be life-threatening. 5. Hemolytic crisis. Most sickle cell patients establish a stable, tonic level of hemolysis. Rarely, for obscure reasons, they experience a catastrophic fall in hematocrit, increasing intensity of jaundice, and increasing reticulocyte count. This is called a "hemolytic crisis." b. Effects of vaso-occlusion 1. Dactylitis. Resulting presumably from infarction or ischemia of the bones of the hands and feet, this is often the presenting manifestation of sickle cell disease in a six-months-old infant. The hands and feet are swollen and painful.