Disorders of RBCs Flashcards
role of Hgb
–reversibly binds oxygen and CO2 for transport
–adequate Hgb necessary for oxygen delivery to the tissues
RBC/Bus analogy
Bus = RBC
Seats = Hgb
What seats are made of = Iron
Passengers = Oxygen
All diseases of RBCs mean … ?
less oxygen is able to be transported to the tissues
anemia type d/t abnormal Hgb
sickle cell
name for abnormally large, regular Hgb concentration RBCs
macrocytic, normochromic
what anemias have macrocytic, normochromic RBCs?
B12 and folate deficiencies
name for abnormally small, low Hgb concentration RBCs
microcytic, hypochromic
what anemia has microcytic, hypochromic RBCs?
iron deficiency anemia
name for normal size, normal Hgb concentration RBCs
normocytic, normochromic
what conditions have normocytic, normochromic RBCs?
–blood loss
–sickle cell
–aplastic anemia
relationship between microcytic and MCV
microcytic = decreased MCV
relationship between macrocytic and MCV
macrocytic = increased MCV
effect of B12/folate deficiencies on RBCs
negatively affects DNA synthesis in RBCs
normal Hgb levels
Male: 14-18
Female: 12-16
mild anemia Hgb levels
Male: 10-13.5
Female: 10-12
moderate anemia Hgb level
8 - <10
severe anemia Hgb level
< 8
why are anemia symptoms present?
due to decreased oxygen carrying capacity
mild-moderate anemia symptoms
–fatigue
–weakness
–tachycardia
–dyspnea
moderate-severe anemia symptoms
–increased HR and RR
–hypotension, pallor, faintness
–CV symptoms (esp. with exertion)
pathophys cause of weakness in anemia
decreased oxygen to muscles
pathophys cause of fatigue in anemia
decreased energy production
pathophys cause of pallor in anemia
blood redistribution away from skin and toward major organs (compensatory mechanism)
pathophys cause of increased HR, palpitations in anemia
increased cardiac output (compensatory)
pathophys of bone pain in anemia
increased secretion of erythropoietin
pathophys of chest pain/heart failure in anemia
decreased oxygenation of cardiac muscle
pathophys of dyspnea/increased RR in anemia
decreased overall oxygenation
demographic factors of iron deficiency anemia
–elderly
–teenager
–female
–immigrant
–aborigine
–widower
dietary factors of iron deficiency anemia
–low iron, haem iron
–low vitamin C
–excess phytate
–excess coffee/tea
–fad diets
social/physical factors of iron deficiency anemia
–poverty
–poor dentition
–candle burning
–alcohol abuse
–GIT disease
–depression
etiologies of iron deficiency anemia
–decreased INTAKE of iron
–impaired ABSORPTION of iron
–increased DEMAND for iron
–excessive loss (GI bleed, menstruation)
symptoms of iron deficiency anemia
–general symptoms of anemia
–smooth tongue/glossitis/mouth ulcers/cheilosis
–koilonychia (“spoon nails”)
–pica
megaloblastic anemia
condition in which the bone marrow produces unusually large, structurally abnormal, immature RBCs
leading cause of megaloblastic anemia
B12 and folic acid deficiency
why are B12 and folic acid needed in RBCs?
DNA synthesis
who is most likely to have megaloblastic anemia?
elderly
atrophic gastritis
stomach lining has thinned causing decreased intrinsic factor
what do parietal cells produce?
acid (iron absorption) and intrinsic factor (B12 absorption)
most common cause of B12 deficiency
pernicious anemia (autoimmune)
what are some diseases that can cause a reduction of IF?
–Crohn’s
–celiac
–bacterial growth
–parasite
symptoms of B12 deficiency
–symptoms of anemia
–neuropathy
–ataxia
–glossitis
–dementia/psychosis
what is a folate deficiency caused by (broadly)?
decreased intake and increased need
examples of decreased intake for folate deficiencies
–alcoholism
–diet
–cirrhosis
example of increased need for folate
pregnancy
where is folate stored?
liver
main etiology of chronic kidney disease
impaired erythropoietin production
what is erythropoietin?
what is released to tell our bone marrow to make RBCs
relevance of Hgb/Hct in chronic kidney disease
correspond with the degree of kidney insufficiency
symptoms of chronic kidney disease
s/s of anemia
aplastic anemia
–primary condition of bone marrow stem failure
–rare
–autoimmune is most common
what is aplastic anemia characterized by?
pancytopenia
what is pancytopenia?
decreased RBCs, leukocytes, and platelets
treatment of aplastic anemia
–blood transfusions
–bone marrow transplant
–immunosuppressants
–corticosteroids
–drugs to stimulate erythropoiesis
causes of aplastic anemia
–idiopathic (majority)
–high dose exposure to toxic agents (radiation, chemo, insecticides)
–autoimmune mechanisms (complication of infection)
acquired hemolytic anemia
premature destruction of RBCs caused by some external agent
common causes of acquired hemolytic anemia
–autoimmune attack
–blood incompatibilities
–drug reactions
–physical agents (severe burn)
–microangiopathies
what happens with acquired hemolytic anemia?
–formation of immune complexes
–lysis = cell death
symptoms of acquired hemolytic anemia
–low hemoglobin
–increased reticulocyte count
–mild jaundice
–hemoglobinuria
sickle cell anemia
inability to bind Hgb normally; genetic
hemoglobin S
–sickle cell; distorts shape, especially when oxygen is low
–fragile sickle-shaped cells deliver less oxygen to the tissues
cause of pain in sickle cell anemia
misshapen RBCs easily clog blood vessels and break into pieces that disrupt blood flow, leading to ischemia and necrosis
symptoms of sickle cell anemia
–s/s of anemia
–swelling of hands and feet with fever
–painful episodes
pain crisis triggers with sickle cell
–dehydration
–stress
–high altitudes
–fever
–extreme temps
treatment for sickle cell
–O2
–hydration
–pain management
–infection control measures
–blood transfusions
–bone marrow transplants
–genetic counseling and treatment
medication for sickle cell
hydroxyurea
thalassemia
genetic; abnormal Hgb makes erythrocytes microcytic, hypochromic, and of carrying size
treatment for thalassemia
–blood transfusions
–bone marrow transplants
–splenectomy
patho of thalassemia
–genetic disorder occurring mostly in persons of Mediterranean descent
–abnormal Hgb (lack of alpha and beta globin)
symptoms of thalassemia
–delayed growth
–fatigue
–dyspnea
–hepatomegaly
–splenomegaly
–bone deformities
–jaundice
causes of anemia from blood loss
–gross
–occult
rate of blood loss and anemia
–IMPORTANT!
–unable to compensate
–slow = less symptoms
risk factors for polycythemia
–chronic hypoxia
–living at high altitudes
–long-term cigarette smoking
–familial and genetic predisposition
–long-term exposure to CO2
relative polycythemia
isolated decrease in plasma volume, elevating the Hgb, Hct, and RBC count
etiology of relative polycythemia
severe dehydration
primary polycythemia
polycythemia vera
–typically > 60 years
–most often in males (2x)
patho of polycythemia vera
a single stem cell mutates into a cell that overproduces all blood cells except for lymphocytes
symptoms of polycythemia vera
–HA
–fatigue
–weight loss
–dyspnea
–HTN
–clotting problems
–ruddy color
–intense/painful itching made worse by heat or exposure to water (aquagenic pruritis)
biggest concern with polycythemia vera
CV events (stroke/MI)
etiology of secondary polycythemia
adaptive (compensatory) response to tissue hypoxia
purpose causing secondary polycythemia
provide more O2 carriers by increasing RBC production
effects of increased blood viscosity and blood volume in secondary polycythemia
–HTN (HA, concentration issues, ruddy, cyanosis)
–decreased blood flow issues (DVT, hemorrhage. angina)
effects of hypermetabolism in secondary polycythemia
–night sweats
–weight loss
effects of increased RBCs and H&H in secondary polycythemia
–itching
–pain in fingers and toes
