Hematopoietic System

Hematopoiesis

process of forming blood

Plasma

liquid protein

Hemoglobin

oxygen-carrying component, protein in RBC, gives red color (brighter the red = more oxygen).

Hematocrit

amount of blood volume occupied by erythrocytes (%).

Hemostasis

stoppage of blood flow.

Normal Hemostasis

when it seals a blood vessel to prevent blood loss and hemmorhage

Abnormal Hemostasis

causes inappropriate clotting or clotting is insufficient to stop blood flow.

Stages of Hemostasis

vessel spasm, formation of platelet plug, coagulation cascade ends in formation of fibrin clot (holds the blood in place). Plasmin dissolves clots.

WBCs (leukocytes)

key players in the inflammatory response and in fighting infections. Normal Range = 5,000 to 10,000 cells/mL.

Leukocytopenia

decreased white blood cell levels

Leukocytosis

increased white blood cell levels

Neutrophils

one type of leukocyte. usually the first to arrive at the site of infection. Normal Range: 2,000 - 7,500 cells/mL

Neutropenia

decreased levels of neutrophils. neutrophils < 1500 cells/mL . Causes: bone marrow disorders, bone marrow cancer, increased use of neutrophils, drug suppression, vitamin B12 and folate deficiency.

Manifestations of Neutropenia

frequent infections, signs and symptoms of infection (fever, malaise, and chills), infections of respiratory tract, mouth ulcerations. Tx: hematopoietic growth factors (filgrastim), reverse isolation.

Infectious Mononucleosis

kissing disease d/t oral transmission (saliva). Most prevalent in adolescents and young adults. Caused by Epstein-Barr virus in the herpes family (infect B cell to make heterophile antibodies, once disease is eliminated, few B cells remain altered/ asymptomatic infection). Very slow onset (insidious), Incubation = 4-8 weeks.

Manifestations of Infectious Mononucleosis

anorexia (no appetite) , malaise, and chills, leukocytosis, fever, headache, sore throat, and lymphnopathy. Splenomegaly (higher chance of spleen rupture). Dx: monospot test (heterophile antibodies). Tx: symptomatic and supportive, acute illness usually lasts 2-3 weeks, may not fully recover for 2-3 months.

Lymphomas

cancer of lymph nodes, originates in a single lymph node or chain (cervical), abnormal proliferation of lymphocytes, linked to Epstein Barr virus, most common hematologic cancer in the U.S. Two main types: Hodgkin's and Non-Hodgkins.

Hodgkin's lymphoma

Reed-sternberg cell in lymph nodes, originates in lymph nodes of upper body, metastasize from lymph node to lymph node. M & F 20-40. M > 50. Better prognosis

Non-Hodgkin's lymphoma

No reed-sternberg cells in nodes, originates in any lymph node, metastasize in scattered pattern, any age, more common, poorer prognosis.

Manifestations of hodgkins/ Non- hodgkins

painless enlarged lymph nodes, fever, malaise, fatigue, weakness, night sweats, prutitis (itchy), loss of appetite & weight loss, splenomegaly and hepatomegaly.

Leukemia

Second most common blood cancer, M > F. leukemia cells (leukocytes) abnormally proliferate, immature (useless), do not die when they should, crowding normal blood cells. Risk Factors: exposure to chemical, viral, and radiation mutagens, smoking, use of chemotherapy, certain diseases (Down Syndrome). 4 types.

Manifestations of Leukemia

leukopenia, anemia, thrombocytopenia, lymphadenopathy, joint swelling, bone pain, weight loss, anorexia, and fatigue/weakness.

Multiple Myeloma

plasma cell cancer, affects > 50 males, African American, often well advanced upon diagnosis (too late). Excessive number of plasma cells invade the bone marrow crowding the normal cells. Secretes Bence Jone proteins excreted in the urine (causes kidney damage), invade the bone causing destruction (leads to hypercalcemia and pathologic features).

Manifestations of Multiple Myeloma

anemia, thrombocytopenia, leukopenia, decreased bone density, bone pain, hypercalcemia, renal impairment (CRAB = calcium, renal failure, anemia, and bone damage).

RBCs (erythrocytes)

transport oxygen and carbon dioxide. Normal Range: 4-6 million cells/mL.

Erythropoiesis

production of erythrocytes, erythropoietin (secreted by kidneys), needs iron to occur.

Anemia

too little RBCs

Polycythemia

too much RBCs

Anemia

deficiency in RBCs (low rbc count, low Hgb/Hct or both). Results in decreased oxygen delivery to the body's cells. Causes: blood loss, nutritional deficiencies (iron, B12, folate), destruction of RBCs, abnormal bone marrow function, decreased erythropoietin, inadequate maturation of RBCs

General Manifestations of Anemia

weakness, fatigue, decreased activity tolerance, pallor, shortness of breath/ dyspnea, decreased O2 saturation, tachycardia, murmur, orthostatic hypotension, and syncope (fainting).

All symptoms usually because of lack of O2.

Types of Anemia

Iron-deficiency, B12 deficiency/Pernicious, Folic acid deficiency, Aplastic, Hemolytic (sickle cell and thalassemia), secondary to renal disease.

Iron Deficiency Anemia

common in infants, older adults, young adult women (pregnancy and menses). Iron is necessary for hemoglobin production, RBCs are microcytic and hypochromic. Causes: decreased iron consumption, decreased iron absorption, and chronic blood loss. Tx: identify and treat the cause, increase dietary intake, and administer iron supplements.

Additional manifestations Iron-Deficiency Anemia

cyanosis to sclera, decreased appetite, and pica.

Pernicious Anemia (B12)

vitamin B12 is required for DNA synthesis, keep nerves and blood cells healthy. RBCs macrocytic (huge) immature. Causes: B12 deficiency/ lack of intrinsic factor, atrophy of gastric mucosa, total gastrectomy, malnutrition, and vegan. Tx: injectable B12 monthly.

Additional Manifestations for pernicious anemia (B12)

hypoxemia (low O2 in blood), paresthesia, unsteady gait, and memory changes

Folic Acid deficiency anemia

folic acid is required for DNA synthesis, keeps blood cells healthy. RBCs macrocytic immature. Causes: folic acid deficiency, poor nutrition, alcoholism, malabsorption d/t Chron's disease. Tx: folic acid replacement.

Additional Manifestations for Folic Acid deficiency anemia

similar to B12/ pernicious anemia except nervous system remains normal (no paresthesia).

Aplastic Anemia

bone marrow suppression of all new stem cells causing deficiency in all blood cells. Causes: idiopathic, autoimmune, medications, medical treatment, viruses, and genetic abnormalities. Tx: identify and manage underlying cause, oxygen therapy, infection treatment, bleeding precautions, and stem cell transplant.

Additional Manifestations for Aplastic Anemia

pancytopenia (cells in bone marrow are suppressed), anemia, leukopenia, and thrombocytopenia.

Hemolytic Anemia

excessive erythrocyte destruction, bone marrow cannot increase production to make up for destruction. Causes: idiopathoc, autoimmune, genetics, infections, blood transfusion reactions, lead poisoning, crushing injuries. Several types: sickle cell anemia, thalassemia, erythroblastosis fetalis (fetal anemia).

Additional Manifestations for hemolytic anemia

jaundice and dark urine

Sickle Cell Anemia

autosomal recessive disorder: hemoglobin S causes erythrocytes to be abnormally shaped, rigid, and clump together. Abnormal erythrocytes carry less oxygen and clog vessels causing hypoxia and tissue ischemia. More common in people of African and Mediterranean descent.

Additional manifestations of sickle cell anemia

severe pain and swelling, frequent urination, excessive thirst, fever, jaundice, hypoxia, damage to organs.

Sickle Cell Crisis

painful episodes that can last for hours or days, pain caused by tissue ischemia and necrosis. Triggers to crisis: dehydration, stress, high altitudes, infections, and hypoxia. Tx: no cure, palliative, hydroxyurea, avoid triggers, control pain.

Thalassemia

autosomal dominant disorder: abnormal form of hemoglobin which causes excessive destruction of RBCs. RBCs are microcytis, hypochromic, and abnormally shaped. Most common in people of Mediterranean descent. Symptoms appear during first year of life. Tx: blood transfusion, chelation therapy, and splenectomy.

Additional Manifestations for Thalassemia

delayed growth and development, bone deformities in the face, and jaundice.

Polycythemia Vera

Abnormally high erythrocytes d/t abnormality with the JAK2 gene. Rare, M > F, considered a neoplastic (cancer) disease. Increased RBCs: increased blood volume and viscosity, leading to tissue ischemia and necrosis. Complications: thrombosis, hypertension, heart failure, hemorrhage, splenomegaly, and hepatomegaly. Tx: phlebotomy and managing clotting disorders

Manifestations of Polycythemia Vera

cyanotic or plethoric skin, high blood pressure, tachycardia, dypnea, headaches, visual abnormalities.

Platelets (thrombocytes)

role in blood clotting, coated with sticky material that causes them to adhere to irregular surfaces, contain contractile proteins to pull together edges of a wound. Normal Levels: 150,000 to 400,000 cells/mL . Thrombocytosis = increased levels (more clotting), Thromvocytopenia = decreased levels (more concerning).

General manifestations of bleeding

epistaxis (nose bleed), melena (blood in stool), ecchymosis (bruising of skin), hematuria (blood in urine), bleeding gums, hypotension, and tachycardia.

Hemophilia

X-linked recessive disorder, presents in childhood, females rarely present with the disease. Two types: A and B. Manifestations: bleeding or indications of bleeding. Tx: replace clotting factors and bleeding precautions. Desmopressin (DDAVP) for type A.

Hemophilia Type A

deficiency of clotting factor VIII

Hemophilia Type B

deficiency of clotting factor IX

von WIllebrand's disease

hereditary, deficiency of protein von Willebrand factor, decreased platelet adhesion and aggregation. Manifestations: bleeding, especially from mucous membranes (epistaxis, gums, excessive menstrual bleeding).

Disseminated Intravascular Coagulation

life-threatening complication of many conditions (infection in blood, pregnancy, sepsis, poisionous snake bites). Results from inappropriate immune response, widespread coagulation followed by massive bleeding because of the depletion of clotting factors. Manifestations: tissue and organ ischemia and abnormal bleeding. Complications: shock and multi-system organ failure. Tx: identify and treat underlying cause, replace clotting components, maintain balance b/t preventing clots and treating bleeding. Not very good outcomes.