Chapter 29 Flashcards
What is anemia
Anemia is a reduction in the total number of erythrocytes in the circulating blood or a decrease in the quality or quantity of hemoglobin. It refers to a true decrease in erythrocyte number, rather than a relative decrease due to increases in plasma volume (hemodilution).
What are the three common general causes of anemia
The three common general causes of anemia are:
(1) blood loss (acute or chronic)
(2) impaired erythrocyte production
(3) increased erythrocyte destruction It can also result from a combination of these three factors.
what is the main clinical effect of anemia
The main clinical effect of anemia is a reduced oxygen-carrying capacity of the blood resulting in tissue hypoxia
What are some general symptoms of anemia
General symptoms of anemia can include shortness of breath (dyspnea), a rapid and pounding heartbeat, dizziness, and fatigue. Symptoms vary depending on the body’s ability to compensate. Mild anemia may only cause problems during physical exertion.
What body systems are generally involved in compensating for anemia
Compensation for anemia generally involves the cardiovascular, respiratory, and hematologic systems.
What type of anemia is posthemorrhagic anemia (acute blood loss)?
Posthemorrhagic anemia is a normocytic-normochromic anemia
What are the initial compensatory mechanisms for acute blood loss?
The initial compensatory mechanism for acute blood loss is peripheral blood vessel constriction, which diverts blood flow to essential vital organs. Decreased blood flow to the kidneys activates the renin-angiotensin response, causing salt and water retention to increase blood volume
What happens to plasma volume and hematocrit within 24 hours of acute blood loss?
Within 24 hours of acute blood loss, lost plasma is replaced by fluid movement from tissues, causing an increase in plasma volume and lowering of hematocrit due to resulting hemodilution
What happens to neutrophils and platelet counts in the early recovery from acute blood loss?
A transient increase in the number of circulating neutrophils occurs within a few hours, and the platelet count can rise significantly during the early recovery from acute blood loss
What is the primary treatment focus for acute blood loss anemia?
The primary treatment focus for acute blood loss anemia is to correct the underlying problem that caused the blood loss. Fluid replacement (saline, dextran, albumin, or plasma) is typically used to restore blood volume, and transfusion of fresh whole blood may be necessary for large losses.
What characterizes anemia from chronic blood loss ?
Anemia from chronic blood loss occurs if the blood loss is greater than the replacement capacity of the bone marrow. It can lead to iron deficiency anemia (IDA).
What should be evaluated in adults with unexplained iron deficiency anemia ?
In adults with otherwise unexplained IDA, an occult source of blood loss such as a bleeding ulcer or a malignancy should be evaluated
What is the morphologic classification of anemia in iron deficiency anemia (IDA)?
Iron deficiency anemia (IDA) is a microcytic-hypochromic anemia, meaning the erythrocytes are small and have a reduced hemoglobin concentration
What is the worldwide prevalence of iron deficiency anemia (IDA)?
Iron deficiency anemia (IDA) is the most common nutritional disorder worldwide, affecting 10% to 20% of the world’s population.
What are the main causes of iron deficiency anemia (IDA)?
The main causes of iron deficiency anemia (IDA) include:
(1) dietary deficiency
(2) impaired absorption (e.g., celiac disease)
(3) increased requirement
(4) chronic blood loss
(5) chronic diarrhea
What are some common clinical manifestations of iron deficiency anemia (IDA)?
Common clinical manifestations of iron deficiency anemia (IDA) include pallor, fatigue, weakness, shortness of breath, palpitations, and dizziness. Other signs can include cheilosis (scales and fissures of the mouth), stomatitis (inflammation of the mouth), and glossitis (painful, bald, fissured tongue), as well as koilonychia (concave, ridged, and brittle nails).
What are the characteristic laboratory findings in iron deficiency anemia (IDA)?
Characteristic laboratory findings in iron deficiency anemia (IDA) include decreased levels of hemoglobin and hematocrit, and the finding of microcytic (low MCV) and hypochromic (low MCHC) erythrocytes. Decreased serum iron, ferritin, and transferrin saturation levels are also found.
What is the initial step in the treatment of iron deficiency anemia (IDA)?
An initial step in the treatment of iron deficiency anemia (IDA) is to identify and eliminate sources of blood loss
What is the typical medical treatment for iron deficiency anemia (IDA)?
The typical medical treatment for iron deficiency anemia (IDA) is oral iron replacement therapy. Parenteral iron replacement is used in specific instances.
What is anemia of inflammation (AI) (also known as anemia of chronic disease)?
Anemia of inflammation (AI) is a mild to moderate anemia resulting from decreased erythropoiesis and impaired iron utilization in individuals with chronic diseases that produce systemic inflammation. It is often normocytic-normochromic initially but can become hypochromic and microcytic.
What are some common underlying causes of anemia of inflammation (AI)?
Common underlying causes of anemia of inflammation (AI) include chronic infections, cancer, chronic inflammatory or autoimmune diseases (e.g., rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease), aging, chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), chronic kidney disease, and critical illnesses after acute events.
What are the key pathophysiologic mechanisms contributing to anemia of inflammation (AI)?
Key pathophysiologic mechanisms in anemia of inflammation (AI) include:
(1) decreased erythrocyte life span
(2) suppressed production of erythropoietin
(3) ineffective bone marrow response to erythropoietin
(4) altered iron metabolism and iron dynamics in macrophages (increased hepcidin leads to reduced iron absorption and sequestration in macrophages).
What are some characteristic laboratory findings in anemia of inflammation (AI)?
Characteristic laboratory findings in anemia of inflammation (AI) include low levels of circulating iron and reduced levels of transferrin, but very high total body iron storage. Individuals often show a failure to respond to conventional iron replacement therapy. Total iron-binding capacity (TIBC) is often low or normal, serum ferritin levels are normal or high, and soluble transferrin receptor concentrations are low.
What is thrombocytopenia?
Thrombocytopenia is a condition characterized by an abnormally low number of platelets in the blood, typically defined as a platelet count less than 150,000/μL.
What are some common causes of thrombocytopenia?
Common causes of thrombocytopenia include:
Primary immune thrombocytopenia (ITP)
◦Drug-induced immune thrombocytopenia (e.g., heparin-induced thrombocytopenia)
◦Infections (viral, sepsis, H. pylori, malaria)
◦Hypersplenism
◦Chronic alcohol abuse
◦Nutrient deficiencies (folate, vitamin B12, copper)
◦Autoimmune disorders (e.g., SLE)
◦Pregnancy
◦Bone marrow suppression (e.g., aplastic anemia, malignancy)
What are some clinical manifestations of thrombocytopenia?
Clinical manifestations of thrombocytopenia can include purpura (red or purple spots on the skin), petechiae (small red or purple spots), easy bruising, nosebleeds (epistaxis), gum bleeding, GI bleeding, and excessive menstruation. Spontaneous bleeding can occur with very low platelet counts
What is thrombocythemia (or thrombocytosis)?
Thrombocythemia (or thrombocytosis) is defined as a platelet count greater than 450,000/μL of blood. It can be primary (essential) or secondary (reactive).
What are some potential complications of thrombocythemia?
Potential complications of thrombocythemia include intravascular clot formation (thrombosis) and hemorrhage
What are qualitative alterations in platelet function characterized by?
Qualitative alterations in platelet function are characterized by an increased bleeding time in the presence of a normal platelet count.
What are some clinical manifestations associated with qualitative alterations in platelet function?
Clinical manifestations associated with qualitative alterations in platelet function include spontaneous petechiae and purpura, and bleeding from the GI tract, genitourinary tract, pulmonary mucosa, and gums
What is impaired hemostasis generally associated with?
Impaired hemostasis, or the inability to promote coagulation and develop a stable fibrin clot, is commonly associated with liver dysfunction or lack of vitamin K.
How does vitamin K deficiency lead to impaired hemostasis?
Vitamin K is required by the liver for the synthesis and regulation of prothrombin and other clotting factors (VII, IX, X). Deficiency leads to decreased levels of these factors and impaired coagulation.
How does liver disease lead to impaired hemostasis?
The liver produces most of the factors involved in hemostasis; therefore, damage to the liver frequently results in diminished production of clotting factors.
What is disseminated intravascular coagulation (DIC)?
Disseminated intravascular coagulation (DIC) is an acquired clinical syndrome characterized by widespread activation of coagulation resulting in the formation of fibrin clots in small vessels throughout the body. This can lead to both thrombosis and bleeding due to consumption of clotting factors and platelets.
What are some common clinical conditions associated with DIC?
Common clinical conditions associated with DIC include sepsis, malignancy, massive trauma, obstetrical complications (e.g., placental abruption, eclampsia), and severe toxic or immunologic reactions (e.g., severe transfusion reaction).
What are some clinical manifestations of acute DIC?
Clinical manifestations of acute DIC can include rapid development of hemorrhaging (oozing) from venipuncture sites, surgical wounds, ecchymotic lesions (purpura, petechiae), and hematomas. Bleeding may occur from multiple sites.
What are thromboembolic disorders?
Thromboembolic disorders are conditions within the blood vessels that predispose an individual to develop clots spontaneously. A thrombus is a stationary clot attached to the vessel wall.
What are some risk factors for venous thromboembolism (VTE)?
Risk factors for venous thromboembolism (VTE) include older age, malignancy, inflammatory disorders (e.g., rheumatoid arthritis), and inherited thrombophilia.
