Medical Scribe Part 2

Common Diseases of the Blood and Blood-Forming Organs The most common problem related to this system is anemia, a decrease in RBC mass that can be caused by a number of different disease processes. Anemia is generally a sign of a disease but is commonly used as a diagnosis until the cause is discovered. Anemia can be serious if the cause is not determined or cannot be corrected. Disorders of WBCs are usually secondary to other diseases rather than as a primary disease. Infections demand an increased need for WBCs because they are used up while fighting the invader. This can lead to leukocytopenia, a decrease in WBC number. Any disorders of the blood-forming organs (spleen, bone marrow, and lymph nodes) can lead to secondary disorders of this system. Leukemias, lymphomas, and myelomas are the primary tumors affecting the system. Disorders of Red Blood Cells Any increase or decrease in number or size of RBCs will affect the mass or volume. Red cell mass is important because it directly affects the amount of hemoglobin available (oxygen-carrying potential). Commonly, the problem is not enough red cell mass, leading to anemia. Too much red cell mass is called erythrocytosis, the most common type of which is a condition called polycythemia. Consider This... It takes a red blood cell 20 seconds to circulate through the entire body. Anemia Description. Etiology. Anemia is commonly due to a low number of RBCs or a decrease in hemoglobin in RBCs. Acute hemorrhage or chronic bleeding can lead to a low number of circulating RBCs and, thus, anemia. Any disease of the liver, spleen, or bone marrow can also lead to anemia. For instance, if the cells are broken down (hemolyzed) too soon, this can lead to a decrease in cell number; if cells are not formed quickly enough to replace the worn cells, the number of circulating cells will be low. If cells are formed abnormally, their ability to carry oxygen can be impaired because although the number of cells might be adequate, their oxygen-carrying ability is not. Dietary deficiencies often lead to an inadequate supply of nutrients to make RBCs. Symptoms. Despite the cause, the symptoms of anemia are fairly common. The individual suffering from anemia commonly is pale or has a condition of pallor. Facial paleness can be difficult to determine, but further examination of the mucous membranes of the mouth and conjunctiva of the eyes will reveal definite paleness. The nail beds also might be noticeably pale in color. Anemic individuals are weak and suffer from fatigue due to poor oxygenation of muscle tissue. Shortness of breath, dyspnea (DISP-nee-ah; dys = difficult, pnea = breathing), tachycardia (TACH-ee-KAR-dee-ah; tachy = fast, cardia = heart), and tachypnea (TACK-ip-NEE-ah; tachy = fast, pnea = breathing) are common as the heart and lungs attempt to meet the body's oxygen need. Headache, irritability, and syncope (SIN-koh-pee; fainting) can also be symptoms. Diagnosis. Anemia can be very simple or related to a complicated or chronic disease. For simple cases, a history and physical examination along with blood tests measuring the level of hemoglobin, hematocrit, iron, folic acid, and vitamin assist in diagnosis. Microscopic examination of the size and shape of the red cells also provides further clues to the type of anemia. More complicated anemias, or those caused by chronic disease, might need further testing, including urine analysis, stool sampling, endoscopy, colonoscopy, and bone marrow biopsy. Treatment. Determining the cause of anemia is very important because treatment is directed at the cause. Therefore, treatment for anemia varies, depending on cause or type of anemia. Some anemias can be cured, whereas others, such as sickle cell anemia, are not curable. Prevention. Eating a healthy diet including foods high in iron and B complex vitamins will prevent deficiency anemias. More complicated types might not be preventable or treatable. Iron Deficiency Anemia Description. Iron deficiency anemia arises when there is insufficient iron for the body to produce the oxygen-carrying component, hemoglobin, within RBCs. Etiology. Iron deficiency anemia can be due to a loss of iron, such as from chronic blood loss, or to an inadequate intake of iron such as from low dietary intake of iron. Chronic blood loss can be due to bleeding hemorrhoids, gastrointestinal bleeding, and heavy or prolonged menstrual flow. Iron deficiency anemia is commonly seen in females during times of increased iron demand as occur during pregnancy and breastfeeding. During their menstrual years, females often have iron loss due to a combination of menstruation and inadequate dietary intake of iron. Symptoms. Symptoms previously described in the anemia section pertain here as well, but, briefly, include pallor, weakness, fatigue, and dyspnea. Diagnosis. History and physical examination along with blood tests indicating low levels of hemoglobin, iron, or both assist in diagnosis of an iron deficiency. For cases caused by bleeding, further tests include looking for the presence of blood in urine and stool samples. Gastroscopy and colonoscopy also can help determine the origin of the bleeding. Treatment. Treatment is aimed at the cause and can include resolving a bleeding problem or increasing dietary intake of iron (foods high in iron are listed in the Healthy Highlight box "Increasing Iron in the Diet"). Iron supplements like ferrous sulfate may also be prescribed. With treatment, iron levels are usually restored to normal within two months. Prevention. Iron deficiency anemia can be prevented by eating a healthy diet high in iron. Anemia related to blood loss can be prevented by seeking medical help at the first sign of excessive bleeding. Healthy HighlightIncreasing Iron in the Diet Individuals with iron deficiency anemia may be able to correct the disorder by just "eating healthy" as opposed to taking iron supplements for the deficiency. Eating healthy overall includes such tips as opting for healthy fats like olive oil or nuts, eating more oily fish such as sardines or tuna, limiting cholesterol, including vegetables and fruit at every meal, and eating more whole grains. In addition to these healthy eating tips, including more iron rich foods in the diet for individuals with iron deficiencies might reduce the need to take supplements. Foods rich in iron include spinach, beef or chicken liver, clams, mussels, or oysters, sardines, turkey, beef, veal, ham, perch or salmon. Heme and nonheme are the two forms of dietary iron. Heme is found in animal foods, while nonheme is found in the plant foods. Individuals who are vegetarian can increase their iron intake by eating more legumes, nuts, and greens. Source: Consumer Reports (2016) Folic Acid Deficiency Anemia Description. Folic acid is a B complex vitamin necessary for the maturation of RBCs. A deficiency in folic acid leads to this type of anemia. Etiology. Deficiency of folic acid can be related to poor diet, overcooking vegetables, or alcoholism. Deficiency can also occur during times of high folic acid need such as those associated with infancy and pregnancy. Symptoms. Symptoms can include fatigue, weight loss, abdominal pain, black or bloody stools, and chest pain. Diagnosis. Blood testing aids in the diagnosis. CBC will show anemia and abnormally large RBCs. The blood folate level will also be low. Bone marrow biopsy is seldom needed but also will show abnormally large red cell size. Treatment. Treatment is aimed at increasing dietary intake of foods high in folic acid such as green leafy vegetables, mushrooms, lima beans, and kidney beans. Folic acid supplements may also be prescribed. If there are no complications to treatment, folic acid levels are usually restored to normal within two months. Prevention. Consumption of a diet high in folic acid aids in prevention. Vitamin Deficiency Anemia Description. Vitamin anemia results from dietary deficiency in or inability of the digestive tract to absorb it. Vitamin is essential for the body to produce RBCs as well as to maintain a healthy nervous system. Etiology. Inability to absorb can be due to several factors, including (1) removal of the small intestine, where is absorbed; (2) having a disease that affects the small intestine, such as Crohn's disease, which interferes with absorption; (3) consumption of a diet deficient in ; or (4) loss or lack of intrinsic factor. This last cause of deficiency is the most common and is also called pernicious anemia. Pernicious Anemia Pernicious anemia usually affects older individuals and has an unusual cause. The mucosa, or lining, of the stomach normally secretes a protein called intrinsic factor. This factor is necessary for vitamin absorption in the small intestine. Those affected have had an autoimmune disorder (a disorder caused by the person's own immune system) that blocks production or destroys the cells that produce this intrinsic factor. Symptoms. Common symptoms include pallor, fatigue, weakness, confusion, depression, and numbness in the hands and feet. Diagnosis. Vitamin deficiencies are diagnosed by a thorough history and physical, CBC, and blood testing for vitamin . A history of small-intestine surgery or chronic disease of the small intestine can be recognized easily and diagnosed. Dietary deficiency and pernicious anemia can be more difficult to diagnose and might need further testing, including a gastroscopy (looking through a scope into the stomach) to view the cells that produce intrinsic factor. Treatment. Treatment depends on the cause of the deficiency. Absorption and dietary deficiency anemia can be treated with oral vitamin tablets, injectable vitamin , or consumption of a diet high in vitamin . Meat, fish, poultry, and milk are all sources of . Pernicious anemia cannot be treated with a change in diet because without intrinsic factor, no amount of can be absorbed. Treatment is a monthly injection of vitamin for the life of the individual. Prevention. Anemias related to poor diet can be prevented by eating a diet high in vitamin . At this time, pernicious anemia is not preventable. Hemolytic Anemia Description. Hemolytic anemia is characterized by increased destruction of RBCs. Etiology. This type of anemia can be related to an antigen-antibody reaction as with Rh factor in blood transfusion reaction or erythroblastosis fetalis. (See Chapter 5 for detailed information.) Hemolytic anemia also can occur due to a disorder of the immune system leading to destruction of one's own erythrocytes. This type of anemia can be severe, and can lead to death of the individual. Hemolytic anemia can be brought on by exposure to chemicals such as benzene; medications, including aspirin and penicillin; and bacterial toxins. Symptoms. Symptoms include pallor, weakness, fatigue, and tachycardia, the last of which can lead to heart failure. Diagnosis. A thorough history and physical along with blood testing will aid in diagnosis. CBC will reveal anemia. A blood smear will reveal an increased number of immature and fragmented red cells. Treatment. Treatment can include prompt exchange transfusion (removal of the individual's blood and replacement by donor blood). Steroid medication along with splenectomy can also help. Folic acid and iron supplements may also be prescribed. Prevention. Hemolytic anemia due to genetic inheritance is not preventable. Acquired hemolytic anemias such as transfusion reactions can be prevented with proper screening. Sickle Cell Anemia Description. Sickle cell anemia is a hereditary anemia, found in people of African descent that causes an abnormal sickle shape of the erythrocyte. Interestingly, sickle cell disease is thought to have developed as a defense mechanism against malaria. The parasite that causes malaria does not grow in cells that sickle, giving these individuals a health advantage in countries where malaria is prevalent. Etiology. The sickle cell has abnormal hemoglobin that causes it to elongate, or sickle, when deoxygenated (as it loses the oxygen load). The cell regains its normal shape after it is reoxygenated (picks up an oxygen load) (Figure 7-2). The sickle shape causes a problem because it does not allow the cell to travel smoothly through small blood vessels. Sickle cells tend to stick and clump together in small vessels, leading to occlusion of the vessel, ischemia, and infarction. This occlusion can occur in any vessel, causing multiple thrombi (clots) and emboli (traveling clots) formations that can lead to infarctions throughout the body, including the vital organs. Symptoms. Symptoms of the disease can vary from mild to severe. Pain in the back, legs, and abdomen is the most common symptom. Other symptoms include fatigue, irritability, swollen joints, leg sores, and gum disease. A classic mark of sickle cell anemia is a group of symptoms called sickle cell crisis, marked by episodes of pain in two or more locations. The pain is often compared in severity to cancer pain. This crisis generally occurs any time the body has an increased need for oxygen, so increased activity, physical stress, and illness can lead to a crisis. The crisis itself increases the body's need for oxygen and often sets off a vicious cycle of oxygen demand and sickling of more cells. Individuals suffering severe symptoms often die in infancy or childhood. Few severely affected individuals live beyond age 20, and even mildly affected individuals usually die before age 50. Diagnosis. Diagnosis is made after history and blood testing. Two blood tests determine sickle cell disease. The first is hemoglobin electrophoresis, which measures the amount of normal and abnormal hemoglobin in the blood. The second is the Sickledex test, which measures the percentage of red sickle cells after mixing a small drop of blood with a deoxygenating agent. A positive test is one in which 25% or more of cells sickle. Treatment. There is no cure for sickle cell disease, and treatment is symptomatic. Therapy with hydroxyurea, a drug that increases levels of hemoglobin, and planned blood transfusions have markedly improved the life expectancy of individuals with sickle cell anemia. An increase in fluid intake to twice the normal amount can also help by increasing blood volume and improving sickle cell movement. Prevention. Because sickle cell anemia is a hereditary disorder, the only prevention is through genetic counseling and the decision by potential carriers to avoid childbearing. Figure 7-2 Sickled erythrocytes. Courtesy of Mark L. Kuss Hemorrhagic Anemia Description. This anemia is caused by the loss of whole blood and can also be called blood loss anemia. A common complication of losing large amounts of blood is hypovolemic shock. Etiology. Acute loss of large amounts of blood, which can be caused by such activities as surgery and any trauma or accident involving blood loss, leads to hemorrhagic anemia. Accidents such as motor vehicle accidents and accidental amputations of arms or legs can easily lead to hemorrhagic anemia. Symptoms. Symptoms include pallor, cool clammy skin, tachypnea, and tachycardia. If large amounts of blood have been lost, other symptoms can arise, including dizziness, fainting, and an extreme thirst as a result of dehydration. Diagnosis. Hemorrhagic anemia is easily diagnosed when the blood loss is external. Internal bleeding also leads to hemorrhagic anemia but is often more difficult to diagnose. A history and physical are necessary, and a CBC showing low cell mass, hemoglobin, and hematocrit is indicative of hemorrhagic anemia. Treatment. Treatment depends on the severity of the condition. In an acute blood loss, controlling or stopping the bleeding is the primary concern. Applying oxygen immediately to increase the oxygen-carrying capacity of the remaining blood supply is also important. Intravenous fluids and liquids taken by mouth help restore fluid volume. In severe cases of blood loss, a blood transfusion might be needed. In chronic or slower blood loss anemia, finding the cause and stopping the bleeding are again the primary focus. If the blood loss is not severe, blood fluid will be replaced within a few hours. The decreased number of circulating erythrocytes will stimulate the bone marrow to step up production of them. Bone marrow can replace large numbers of blood cells, thus correcting this type of anemia. Consuming a healthy diet that is especially high in protein and iron will help restore the body's blood reserves and return it to a healthy state. Prevention. Accident prevention and controlling chronic bleeding are helpful in preventing hemorrhagic anemia. Aplastic Anemia Description. Aplastic anemia is characterized by failure of the bone marrow to produce blood components. A severe decrease or total absence of erythrocytes, leukocytes, and thrombocytes, called pancytopenia (pan = all, cyto = cell, penia = decrease), is common. Etiology. This anemia is due to injury or destruction of the blood-forming area of the bone marrow. Causes include chemotherapy, radiation, viruses, and chemical toxins. Symptoms. This decrease in blood cells leads to anemia, infection, and hemorrhage, respectively. Diagnosis. Aplastic anemia is diagnosed by using a history and physical examination with blood testing. A CBC will show a low hemoglobin and hematocrit, indicative of anemia. Blood can also be tested for iron and folic acid levels to rule out these types of anemia. A reticulocyte count test measures reticulocytes, or immature RBCs, and helps determine whether the bone marrow is producing RBCs as it should. In aplastic anemia, the reticulocytes numbers will be low. Because blood cells are formed inside bone, a bone marrow aspiration or biopsy can also be used. In both of these tests, a large-bore needle or surgical instrument removes small pieces of marrow and bone, respectively. The cells are then examined under a microscope to look for abnormal cells. In aplastic anemia, the red cell production and numbers are low. Other tests that can be helpful in diagnosis include X-ray, computed tomography (CT) scan, and ultrasound. These tests help rule out cancer, infection, and other types of anemia. Treatment. Severe cases of aplastic anemia need emergency medical treatment to avoid a fatality. Treatment includes discontinuing or avoiding the causative agent. Other treatment might include bone marrow transplantation and blood transfusions. Prevention. Avoiding causative agents is helpful in prevention, but too often, the causative agent is unknown or unavoidable, making prevention impossible. Polycythemias Polycythemia (Primary or Vera) Description. Polycythemia is also called primary polycythemia or polycythemia vera. It is a condition of too many blood cells. Etiology. Primary polycythemia is caused by hyperplasia (hyper = excessive, plasia = growth) of the cell-forming tissues of the bone marrow, leading to an increase in the production of erythrocytes, leukocytes, and thrombocytes. This disease has an unknown etiology. Symptoms. The increase in erythrocytes leads to an increase in blood volume, which raises blood pressure and causes an increase in the workload on the heart. The spleen, an organ of blood cell storage, is enlarged. The mucous membranes are reddened in color, and the eyes often appear bloodshot. The palms of the hands are noticeably a deeper red color (Figure 7-3). Diagnosis. Polycythemia can be accidentally discovered through routine blood testing before a person has any symptoms. Hemoglobin (the protein that carries oxygen in RBCs) will be abnormally high, as will the hematocrit (the percentage of RBCs in the total blood volume). Platelets and WBCs might also be increased. Treatment. Treatment is to reduce the red cell count and, thus, blood volume. Phlebotomy or removal of blood, such as with blood donation, at regular intervals will reduce the volume and is a common treatment. Prevention. Polycythemia cannot be prevented. With treatment, symptoms and complications can be prevented or delayed. Figure 7-3 Polycythemia—reddened palms. Courtesy of Mark L. Kuss Secondary Polycythemia (Erythrocytosis) Description. Secondary polycythemia, or erythrocytosis (erythrocyte = red cell, osis = condition of), differs from primary polycythemia in that only red cell numbers are increased. Etiology. Erythrocytosis is a protective mechanism of the body to meet the need for extra oxygen, a normal compensatory mechanism for people who are not getting enough oxygen. It is seen as a positive change in people in high altitudes where oxygen content of air is low. Also, highly trained athletes can have erythrocytosis to meet the high oxygen demands of the body's muscle tissue. Certain respiratory conditions and circulatory conditions cause a decrease in oxygen supply to the tissues and thus stimulate erythrocytosis also. When the conditions calling for extra oxygen are returned to normal, the erythrocytosis disappears. For example, if people living in high altitudes move to a lower altitude, the red cell count will return to a normal level. Smoking, which impairs RBCs' ability to deliver oxygen to body tissues, can cause secondary polycythemia. Symptoms. Headaches, weakness, and fatigue are often the first symptoms of secondary polycythemia; lightheadedness and shortness of breath are also common. If the polycythemia is due to disease of the lungs, the face might be reddened and become blue during exercise or other exertion. Diagnosis. Following a history and physical exam, diagnosis of secondary polycythemia is assisted by blood testing. Arterial blood gases (ABGs) testing shows the concentration of oxygen in an artery, and low oxygen levels in this test can be indicative of secondary polycythemia. Blood levels of erythropoietin, a hormone that stimulates the bone marrow to produce RBCs, can also be measured. Normal or low erythropoietin levels can indicate secondary polycythemia. X-ray and CT imaging studies also can rule out liver, kidney, or spleen disorders or tumors. Treatment. Secondary polycythemia is treated by addressing the cause of the disorder. For example, lung disorders such as those caused by cigarette smoking can cause secondary polycythemia; not smoking helps treat the lung condition and improve the secondary polycythemia. Prevention. In some cases, secondary polycythemia can be prevented by stopping the causative factor or by not doing the things that deprive the body of needed oxygen. Living at high altitudes and smoking, for example, can be avoided or stopped.

Any decrease in oxygen-carrying ability of the RBC is anemia. There are more than 400 types of anemia; the three most common types are related to deficiency of iron, folic acid, and vitamin .

hematologic system. The major function of the blood is to transport necessary nutrients to the cells and to aid in the removal of wastes. The blood also transports hormones secreted by the endocrine system. In addition, the white blood cells (leukocytes) are important in infection prevention. The blood is composed of a variety of substances of which plasma, a straw-colored liquid, makes up about 55% of the total. The formed elements constitute the other 45%. They include the erythrocytes (red blood cells, or RBCs), leukocytes (white blood cells, or WBCs), and platelets (clotting fragments) (Figure 7-1). Figure 7-1 Blood components. Descriptive properties of the blood include its color, volume, viscosity, and pH. Blood is bright red in the arteries due to its oxygen content; blood in the veins is a dark red (often depicted as blue) due to the absence of oxygen. The average adult has about 75 ml/kg of body weight of circulating blood (5-6 liters or approximately 1.5 gallons). The viscosity or density of blood is about three or more times greater than water. Blood is slightly alkaline (pH 7.35-7.45). The erythrocytes transport oxygen from the lungs to the tissues. The normal erythrocyte count is 4.2 to 6.3 million. Erythrocytes formed in the bone marrow do not reproduce. Erythrocyte production increases when oxygen needs increase. During their life span, which is only about 120 days, red cells become worn and often ragged from bumping and bouncing into the vessel walls of the circulatory system. The worn RBCs are filtered out of circulation by the spleen and liver. These organs are responsible for breaking down the RBCs and saving the iron component for reuse in the development of new RBCs. Consider This... The average-sized human creates and kills approximately 15 million blood cells per second. Hemoglobin, a component of the RBC, is important in the transport of oxygen. A low level of hemoglobin in the blood reduces the level of circulating oxygen. The normal level of hemoglobin for an adult male is 13.5-18 g/100 ml, and 12-16 g/100 ml for an adult female. Leukocytes protect the individual from infections. The average white blood cell count for an adult is . A count higher than 11,000 usually indicates the presence of an infection. See Chapter 4, "Inflammation and Infection," and Chapter 5, "Immune System Diseases and Disorders," for more information about leukocytes. Platelets, also called thrombocytes, produce the thrombokinase used in the clotting process. The average number of platelets in adults is of blood. The plasma portion of blood is composed of 91% water and 9% plasma proteins. The plasma proteins include (1) albumin, responsible for maintaining osmotic pressure; (2) globulin, responsible for infection fighting; (3) fibrinogen, responsible for part of the clotting process; and (4) prothrombin, also responsible for part of the clotting process. Blood coagulation (clotting) occurs in phases. In the first phase, the platelets, in association with several plasma proteins, agglutinate (clump) at the site of injury or blood loss, and thromboplastin is formed. In the second phase, prothrombin is converted to thrombin in the presence of calcium. In the third phase, thrombin and fibrinogen form fibrin. With the presence of calcium, a fibrin clot is formed. In the fourth phase, the clot is removed through the process of fibrinolysis. Blood is classified by the antigens in the RBCs and the antibodies in the plasma. The antigens are A and B, and the antibodies are anti-A and anti-B. In addition, a factor called Rh is used in the classification system. (See Chapter 5 under "Erythroblastosis Fetalis" and "Blood Transfusion Reaction" for more information.) Blood is typed as A, B, AB, and O: Type A blood has A antigens and anti-B antibodies; type B blood has B antigens and anti-A antibodies; type AB blood has A and B antigens and does not have anti-A or anti-B antibodies; and type O blood has neither A nor B antigens but has both anti-A and anti-B antibodies. The Rh designation is based on 12 distinct antigens. Rh+ blood contains this antigen, but Rh− blood does not. Because of these designations and blood properties, blood transfusion recipients must have a type and cross-match of blood to be certain a reaction will not occur (Table 7-1). Table 7-1RBC Blood Donor and Recipient Chart RBC Recipient (Receiver) O A B AB RBC Donor (Giver) O YES YES YES YES A NO YES NO YES B NO NO YES YES AB NO NO NO YES YES = This type can receive the donated RBCs. NO = This type cannot receive the donated RBCs. The blood-forming organs include the lymph nodes, bone marrow, spleen, and liver. The lymph nodes are found throughout the body along the lymphatic vessels. The lymph nodes filter the lymph and produce the lymphocytes and antibodies important for protection from pathogens. Bone marrow is found in the center part of long bones and in the spongy part of other bones. It is the major blood cell-producing organ in the body. The spleen is found in the upper left quadrant of the abdomen. It produces lymphocytes, plasma cells, and antibodies and filters microorganisms from the blood. It also removes old blood cells from the body. The liver is a large organ found in the right upper quadrant of the abdomen. It has multiple responsibilities for many body systems. The liver functions as a blood-forming organ in intrauterine life and is active the rest of the individual's life as a producer of prothrombin and fibrinogen for blood clotting. Common Signs and Symptoms Signs and symptoms of this system include those related to increases and decreases in the number of blood cells. Diseases affecting the blood-forming organs (primarily spleen, bone marrow, and lymph nodes) can lead to decreased or increased production of cells. Diseases that hemolyze, destroy, or use up the cells lead to a decrease in cell number and volume. Erythrocytopenia (erythro = red, cyte = cell, penia = decrease) leads to anemia (an = without, emia = blood). Anemia does not mean "without any blood"; it means "low or decreased RBC volume." Signs and symptoms of anemia can be minor or major, asymptomatic to life-threatening, depending on cause. Common signs and symptoms include a low erythrocyte count, headache, fatigue, pallor, and shortness of breath. Erythrocytosis (erythrocyte = red cell, osis = condition of) is a condition of increased RBCs. Common signs and symptoms include a high RBC count, reddened skin tones, bloodshot eyes, increased blood volume and pressure, and an increase in the workload of the heart. Leukocytopenia (leuko = white, cyte = cell, penia = decrease) is a decrease in white cell count. Leukocytopenia weakens the immune system because these cells are primary players in the defense system. Neutropenia (neutrophil decrease) and lymphopenia (lymphocyte decrease) can be associated with chronic infection because the numbers are used up during a long-term battle. Signs and symptoms are related to the particular type of infection. Leukocytosis (leukocyte = white cell, osis = condition of) is an increase in white cell count. This condition is a normal response to acute infection. If leukocytosis is related to a tumor, these numbers can be extreme, as in the case of leukemia (leuk = white, emia = blood). Thrombocytopenia (THROM-boh-SIGH-toh-PEE-nee-ah; thrombocyte = platelet, penia = decrease) is a decrease in platelets, leading to a coagulation problem. Signs and symptoms include small hemorrhages in the skin called petechiae (pee-TEE-kee-eye), large areas of bruising or hemorrhage called ecchymoses (ECH-ih-MOH-ses), and epistaxis (EP-ih-STACK-sis; nosebleeds). Bleeding lesions in the mouth, gums, and mucous membranes are also common. Thrombocytosis (THROM-boh-sigh-TOE-sis; thrombocyte = platelet, osis = condition of) is an increase in platelets. This condition is uncommon and usually has no serious side effects (Table 7-2). Table 7-2Blood Cell Abnormalities and Associated Symptoms Condition Symptoms Red Blood Cells Increased Erythrocytosis Reddened skin, increased blood pressure, increased workload on the heart Decreased Erythrocytopenia Anemia White Blood Cells Increased Leukocytosis Usually asymptomatic Decreased Leukocytopenia Weakened immune system Thrombocytes Increased Thrombocytosis Increased clotting Decreased Thrombocytopenia Increased bleeding Diagnostic Tests Diagnostic tests for blood and blood-forming organ disorders include complete blood count with differential and indices. Biopsy of the blood-forming organs also can be helpful in diagnosing disorders of the spleen, lymph nodes, and bone marrow. A complete blood count (CBC) identifies the number of RBCs, WBCs, and platelets per cubic millimeter (Table 7-3) and can be used in the determination of most blood diseases. RBC count and indices can assist in the determination of the different anemias, polycythemia, and erythrocytosis. A differential is a more detailed count, identifying the number of each type of leukocyte. A WBC count and differential can assist in determination of inflammation and infection or tumors of white cells. Hematocrit (Hct) reflects the amount of red cell mass as a proportion of whole blood. Hemoglobin (Hgb) reflects the amount of hemoglobin or oxygen-carrying potential available in the blood. Special measurements of red cells are called indices and include: MCV Mean corpuscular volume; reflects average size of the red cell MCH Mean corpuscular hemoglobin, or average hemoglobin content MCHC Mean corpuscular hemoglobin concentration, or average hemoglobin concentration Table 7-3CBC Normal Values Cells Values Erythrocytes Males Females Hematocrit Males 40-54% Females 38-47% Hemoglobin Males 13-18 g/dl Females 12-16 g/dl RBC indices MCV MCH 27-31 pg MCHC 32-36% Leukocytes Differential Myelocytes Band neutrophils Segmented neutrophils Lymphocytes Monocytes Eosinophils Basophils Platelets Reticulocytes Key: g/dl = grams per deciliter; MCH = mean corpuscular hemoglobin; MCHC = mean corpuscular hemoglobin concentration; MCV = mean corpuscular volume; = cubic millimeter; pg = picograms. Pharmacology HighlightCommon Drugs for Blood and Blood-Forming Disorders Category Examples of Medications Anticoagulants Drugs used to prevent clotting Warfarin, heparin, or dabigatran Antineoplastics Drugs used to treat cancer Alkylating agents Chlorambucil, cyclophosphamide, or lomustine Antimetabolites 5-Flourauracil, clofarabine, mercaptopurine, or methotrexate Antitumor antibiotics Doxorubicin, mitomycin or streptozocin Hormones/antihormones Estrogens, androgens, flutamide, or tamoxifen Other substances Vincristine, l-asparaginase, paclitaxel, carboplatin, cisplatin, desatinib, etoposide, imatinib, indarubicin, nilotinib, ponatinib Vitamins/Minerals Supplements used to support or replace low levels Calcium, chromium, folate, iodine, iron, magnesium, selenium, vitamins A, , , C, D, E, K, or zinc; these may be prescribed individually or in combinations The morphology of each of the cells and platelets can be observed by performing a blood smear. A blood smear is performed by placing a drop of blood on a glass slide, smearing it to spread the cells to a thin layer, and staining and examining it microscopically for abnormal cell morphology or shape. Adding a staining solution to the slide helps in the identification of granular and agranular WBCs. A blood smear can be helpful in determining the cause of anemia, especially sickle cell disease. A bleeding time is used to measure the time it takes the blood to clot. It can assist in determining blood disorders such as hemophilia, thrombocytopenia, or disseminated intravascular coagulation, and liver disease, Vitamin K deficiency, or defective clotting factors. Prothrombin time (PT) and partial thromboplastin time (PTT) are often used in conjunction to evaluate both the clotting time and the function of the coagulation factors. The international normalized ratio (INR) is also used to measure bleeding time. It is most often used to monitor the effectiveness of anticlotting medications such as warfarin. It measures the time it takes for blood to clot and compars it to an average. Biopsy of blood-forming organs can be helpful in diagnosing diseases and disorders. For instance, bone marrow biopsy is performed by boring a needle into the bone of the iliac crest of the hip to obtain tissue that is prepared and microscopically examined. Lymph node biopsy can be performed to determine functioning of the marrow, detect anemias, and diagnose neoplasms.

blood and blood-forming organs