Ch. 23 Objectives
Describe red blood cell count, percentage of reticulocytes, hemoglobin, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin concentration as it relates to the diagnosis of anemia.
-RBC: measures total number of RBCs in a microliter of blood -% of reticulocytes: index of rate of red cell production -hemoglobin: hemoglobin content of blood -hematocrit: red cell mass in a 11 mL plasma volume -MCV: volume or size of red cells -MCHC: hemoglobin concentration in each cell
Explain the determination of the Rh factor.
-The D antigen determines the Rh positive type -The absence of the D antigen determines the Rh negative type
State the changes in the red blood cells that occur with aging.
-capacity of red blood cell replacement decreases with aging -most older aging adults can maintain their hemoglobin and hematocrit levels within a normal range -inability to replace RBCs closely correlates within anemia in older adults
Describe the formation, transport, and elimination of bilirubin.
-insoluble in plasma -attaches to plasma proteins for transport in blood -removed from the blood by the liver and conjugated to a water soluble form so that it can be excreted in bile -unconjugated bilirubin accumulation leads to a yellow discoloration of the skin, called jaundice
Compare characteristics of the red blood cells in acute blood loss, hereditary spherocytosis, sickle cell disease, iron deficiency anemia, and aplastic anemia.
ACUTE -loss of intravascular volume = cardiovascular collapse = shock HEREDITARY SPHEROCYTOSIS - autosomal dominant trait -most common inherited disorder of the red cell membrane -abnormality in membrane proteins that leads to a gradual loss of the membrane surface -red cell forms a spherical shape and cannot easily traverse the spleen SICKLE CELL DISEASE -pain due to microcirculation obstruction IRON DEFICIENCY ANEMIA -dietary deficiency, loss of tron through bleeding, or increased demands -iron is a component of heme; deficiency leads to decreased hemoglobin synthesis and consequent impairment of oxygen delivery APLASTIC ANEMIA -a disorder of pluripotent bone marrow stem cells that result in a reduction of al three hematopoietic cell lines-RBCs, WBCs, platelets
Describe the pathogenesis of hemolytic disease of the newborn.
HDN happens when an Rh negative mother has a baby with an Rh positive father. If the Rh negative mother has been sensitized to Rh positive blood, her immune system will make antibodies to attack her baby. When the antibodies enter the baby's blood, they will attack the red blood cells. This causes them to break down.
Discuss the function of iron in the formation of hemoglobin.
Iron helps form and oxygenate our blood cells and haemoglobin. One of the most important functions of iron is in heme synthesis, which forms haemoglobin, a protein found in red blood cells. Haemoglobin's primary role is to transport oxygen from the lungs to body tissues to maintain basic life functions.
Compare conjugated and unconjugated bilirubin in terms of production of encephalopathy in the neonate.
Kernicterus, or bilirubin encephalopathy, is bilirubin-induced neurological damage, which is most commonly seen in infants. It occurs when the unconjugated bilirubin (indirect bilirubin) levels cross 25 mg/dL in the blood from any event leading to decreased elimination and increased production of bilirubin.
Compare the causes and manifestations of polycythemia vera and secondary polycythemia.
POLYCYTHEMIA VERA -proliferative disease of the bone marrow -absolute increase in total red blood cell mass -accompanied by elevated white cell and platelet counts SECONDARY POLYCYTHEMIA -hypoxic conditions: chronic heart and lung disease, smoking, living at high altitudes
Describe the manifestations of anemia and their mechanisms.
Primary causes: -excessive bleeding -increased destruction of RBCs (hemolysis) -production of defective RBCs -production of insufficient numbers of RBCs Tissue hypoxia gives rise to fatigue, weakness, dyspnea, and sometimes angina
Describe the function of hemoglobin F in the neonate and describe the red blood cell changes that occur during the early neonatal period.
RED BLOOD CELL CHANGES -hemoglobin concentrations at birth are high, reflecting the in utero need for oxygen delivery -during the early neonatal period, there is a shift fro HbF to HbA HEMOGLOBIN F -main hemoglobin that carries oxygen around the body of the developing baby during the last 7 months of pregnancy. Fetal hemoglobin is best suited to the conditions in the womb and the oxygen transport needs of babies before they are born.
Cite the factors that predispose to hyperbilirubinemia in the infant.
The most common cause of jaundice can be ABO incompatibility. Rh incompatibility and type of delivery can be among the controversial factors. Furthermore, some factors may contribute to jaundice, such as congenital infections (Syphilis, CMV, rubella, toxoplasmosis), and age more than 25 years
List the signs and symptoms of a blood transfusion reaction.
back pain. dark urine. chills. fainting or dizziness. fever. flank pain. skin flushing. shortness of breath.