Anemia, Diabetes, and Hypertension PDF

H emodynamics disorders: A nemia  Introductio Blood isncomposed of two main components: a liquid portion called plasma a cellular portion containing red blood cells (erythrocyt...

H emodynamics disorders: A nemia  Introductio Blood isncomposed of two main components: a liquid portion called plasma a cellular portion containing red blood cells (erythrocytes), white blood cells (leukocytes) and platelets (thrombocytes). Blood serves in transport of oxygen, nutrients and ions while acting as a buffer between cells and the environment. The total blood volume in a 70-kg man is approximately 5 L.  CBC Red cell indices WBC count – Mean cell volume (MCV) RBC count average size of RBC WBC differential – Mean cell hemoglobin Hemoglobin (HGB) (MCH) average amount of Hematocrit (HCT) hemoglobin – % of volume in an average RBC occupied by RBCs – Mean cell hemoglobin concentration (MCHC) average concentration of hemoglobin/unit of volume in an average RBC  Hematopoies is It is the process by which blood cells are formed from a stem cell In the maturing fetus, early production of erythrocytes takes place in developing blood vessels. As gestation continues, the production of both red & white blood cells shifts to the fetal liver and spleen and eventually is localized bone marrow and continues there for lifetime A major regulator of RBC production is the hormone erythropoietin that is produced by cells of adult kidney in response to hypoxia. Erythropoietin acts on stem cells in BM to promote  Hematopoies Mature RBCs thatis form are biconcave in structure and lack a nucleus. The unique shape of the mature erythrocyte maximizes surface area and facilitates diffusion of oxygen across the cell membrane RBCs do not contain mitochondria they rely primarily on glycolysis to meet their metabolic needs. The cell membranes of normal RBCs must be strong enough to survive transport under high pressure yet be flexible enough to fit through narrow and winding capillaries. A protein cytoskeleton provides a framework of support to the red blood cell membrane. The function of red blood cells is to transport oxygen to  Anemi a is a reduced number of RBCs or It is a condition in which there decreased concentration of hemoglobin in those cells or both. The mechanism by which the anemia results is generally due to : 1. excess loss or destruction of RBCs 2. reduced or defective production of RBCs  General manifestations of anemia A major feature of anemia is a reduced capacity for the transport of oxygen to tissues. This reduced oxygen delivery can result in: Ischemia Fatigability Breathlessness upon exertion Exercise intolerance Pallor Increased susceptibility to infection  Types of anemia Hemolytic anemia Blood loss anemia Iron-deficiency anemia Cobalamin-deficiency or folate-deficiency anemia Inherited anemia Sickle cell disease Aplastic anemia Thalassem ia  Hemolytic anemia It results from excess destruction of red blood cells (hemolysis). Factors that may cause hemolysis include: – Autoimmune destruction of red blood cells – Certain drugs (example: quinine) or toxins – Cancers such as lymphoma and leukemia – Rheumatoid arthritis – Certain viral infections (parvovirus) – Parasitic infections (malaria)  Blood loss anemia Anemia that results from acute blood loss. With acute loss of large amounts of blood, shock is the major concern. With chronic loss of smaller amounts of blood, iron deficiency is a chief concern. Causes of acute and chronic blood loss include: – Trauma and hemorrhage – Malignancy – Peptic ulcers  Iron-deficiency anemia Iron-deficiency anemia is a major cause of anemia worldwide. It can occur as a result of iron-deficient diets. Vegetarians are at particular as are menstruating or pregnant women due to increased requirement for iron. Iron-deficiency anemia may also result from poor absorption of iron from the intestine or persistent blood loss (e.g., ulcers, neoplasia). Lack of available iron decreased hemoglobin synthesis and subsequent impairment of RBX oxygen-carrying capacity.  Cobalamin-deficiency or f o l a t e - d e fi c i e nCobalamin c y (vitB12) & folic a ci d a re e ss e nt ial n utr i en ts re quired for DNA synthesis & red cell matuarantioen,mresipaectively. Their deficiency lead to formation of abnormal RBCs shape with shortened life spans due to weakened cell membranes. One cause of vitB12 deficiency is pernicious anemia that results from a lack of intrinsic factor production by gastric mucosa, which is required for normal absorption of vitB12 from intestine. Any intestinal abnormalities (e.g. neoplasia, inflammation) that interfere with the production of intrinsic factor can lead to vitB12 deficiency. Folic acid deficiency most commonly results from poor diet, malnutrition or intestinal malabsorption.  Inherited anemia Result from genetic defects in RBC structure or function. Two common genetic disorders: – sickle cell anemia – thalassemia Both of these disorders result from abnormal or absent genes for the production of hemoglobin.  Sickle cell disease Characterized by abnormal hemoglobin (Hb) production that results from a substitution mutation of a single amino acid. Sickle cell disease has several patterns of inheritance: homozygous Hb formed is defective and manifestations are most severe heterozygous