Anemia Flashcards
What is the formation of hemoglobin
succinyl coA and glycine form Pyrroles -> 4 pyrroles form protoporphyrin IX -> Addition of iron forms Heme -> Addition of globin polypeptide completes a subunit -> **4 subunits usually 2 alpha, 2 beta in adults combine to form hemoglobin
Define anemia
Abnormally low number of circulating red blood cells or level of hemoglobin, or both, resulting in diminished oxygen-carrying capacity; a sign NOT a disease
What is the manifestations of Reduced O2 Carrying Capacity
1] Impaired oxygen transport, 2] Reduced red cell indices/Hgb, 3] Signs and symptoms of disease causing anemia
What is the red cell indices
indicators of red cell health and function, done w Hgb…this is a special test
What are the typical causes of anemia?
1] red cell loss (hemolysis/hemorrhage), 2] deficient erythropoiesis, 3] deficient hemoglobin production
What is an example of deficient erythropoiesis
*CKD, bc lack of EPO and red cell production. Too few cells.
What is an example of Low hemoglobin and red count.
GI bleed, fecal occult blood. hemophilia, GIB, women of reproductive age who bleed
If hemoglobin is abnormal what can that indicate?
there is a production issue. eg) Fe deficiency, B12, folate deficiency
What is Hereditary spherocytosis
round red cells are round instead of biconcave –> get trapped more often causing hemolysis
What are the effects of hypoxia
1] Fatigue, 2] Weakness, 3] Dyspnea, 4] Angina, 5] HA (morning), faintness, dim vision (tunnel or less acuity)
Why does angina occur due to hypoxia
body response to low oxygen, incr HR, resp drive, metabolic demand (including on the cardiac muscle), murmurs and angina may show up.
What is the manifestation of blood redistribution when oxygen starved
force blood into the core to support vital organs results in Pallor of skin, mucus membranes, conjunctiva, nails
What is blood loss
Can be Acute or chronic, Fluid enter compartment, dilutes blood, Hgb/Hct fall with normal cell morphology
What is acute blood loss
think hypovolemic/shock due to bleeding
What is chronic blood loss
Chronic loss leads to iron deficiency anemia over time, no volume depletion (microcytic anemia), the slower the blood loss the more you can tolerate it, their hemoglobins will go very low. GIB HgB of 4 compared to trauma pt with HgB of 10.
What is Hemolytic anemia
1] Usually normocytic/normochromic, 2] Increased reticulocyte count, 3] Possible jaundice
What is the pathophysiology of hemolytic anemia
loss of red cells results in the body pushing more of the reticulocytes into the bloodstream faster
What is Hereditary spherocytosis
Autosomal dominant transmission that results in Deficiency of red cell membrane proteins (spectrin, ankyrin). Red cell loses surface area throughout lifespan. Characteristic shape lost, spheres remain, Spherical shape leads to destruction = shorter lifespan/faster turnover =anemia
What are the signs of Hereditary spherocytosis
jaundice, splenomegaly, bilirubin stones
What is aplastic crisis
Aplastic crisis when red cell production disrupted as by virus or metabolic crisis and the bone marrow shuts down
What is the treatment of Hereditary spherocytosis
Tx with splenectomy, bc this is where the cells are getting degraded to frequently, so if you take out the spleen, the cells will last longer.
What is Sickle Cell Anemia
transmitted by recessive pattern results in Point mutation in beta chain of hemoglobin, abnormal substitution. 40% sickling with heterozygotic trait; 80-95% sickling in homozygote
What causes the sickling?
Low oxygen tension, can be brought on by Cold, Stress, Exertion, Infection, Hypoxia, Dehydration, Acidosis
What are the 2 results of sickle cell anemia?
chronic hemolytic anemia, blood vessel occlusion
What is thalassemia A
result of deletion of alpha subunit on Chromosome 16. In severe disease Hgb H formed.
What is thalassemia B
usually caused by point mutations in β subunit. Relative increases in *Hgb A2 and F. Excess alpha chains unstable and precipitate causing cell damage. Prevalent in Mediterranean ppl.
How do you determine the type of thalassemia
DX-hemoglobin electrophoresis, where the run the hemoglobin out on a gel. By the distance that the proteins travel, you can tell which form of HgB you carry. Higher than normal Hgb H = alpha thalassemia
How does thalassemia causes anemia
anemic bc higher turnover of red cells and less oxygen carrying capacity.
List the Disorders of red cell production
1] Decreased bone marrow activity, 2] Metabolic deficiency
How are Disorders of red cell production is assessed
assessed w/CBC. Is it a pan cytopenia? global cell production (white cells are down too) or is it just red cells?
What is the most common type of anemia worldwide?
*iron deficiency anemia due to dietary deficiency or bleeding
what will a deficiency in iron causes
decreased heme production, results in small RBC with low hemoglobin content there it is a microcytic hypochromic anemia also anisocytosis = they do not look the same, poikilocytosis = abnormal morphologic
What is the issue with iron deficiency anemia?
Membrane may become friable and predispose to hemolysis
What is what the MCV indicates
If MCV is lower than normal = microcytic (small red cells), MCV high = macrocytic (big red cells), MCV normal = normocytic
What is reason that iron deficiency is considered hypochromic
*Hemoglobin is responsible for coloring the blood red. In lab terms, it’s a chromogen creates color. if Hgb is low there is less color
Compare hemolytic anemia and iron deficiency anemia
Hemolytic anemia is normocytic and normochromic, they have anemia bc they’re breaking down red cells faster. In IDA cells are microcytic and Hypochromic,
What is the pathophysiology of megaloblastic anemia
impaired nucleic acid synthesis results in Enlarged RBC and deficient nuclear maturation
What is the most common cause of megaloblastic anemia
B12 or folate deficiency
What is why B12 and folate results in megaloblastic anemia
B12 & folate are cofactors in DNA synthesis. Stem cells producing daughter cells, you need 2 things: mitosis & meiosis are processes of nuclear division. So if your nuclear division is slow bc you don’t have enough cofactor to turnover DNA as fast, and cytoplasm is allowed to keep going at a normal pace (bc that process is not impaired) == bigger cells in the end.
What is absorption and storage of vitamin B12
Bound to intrinsic factor made in stomach, Absorbed at terminal ileum; Stored in liver (sufficient for 3 years without intake)
What is use of vitamin B12
Necessary cofactor for methionine and succinyl co-A production in 2 pathways- DNA proteins
What is absorption and storage of folate
Pteroylmonoglutamic acid (reduced to tetrahydrofolate)
What is use of vitamin folate
Also a cofactor in conversion of homocysteine to methionine and conversion of deoxyuridylate to thymidylate (DNA synthesis)
What should suspect with a macrocytic CBC?
B12 and folate levels
What is the pathogenesis of Aplastic anemia (bone marrow depression)
Fatty replacement of bone marrow - loss of all 3 stem cell lines, Remaining cells normal
What is the manifestation of aplastic anemia
Petechiae and bruising from loss of platelets, and infections from WBC loss
What is the cause of aplastic anemia
Often caused by exposures (radiation, chemicals, Felbamate & tegretol [AED])
What is the treatment of aplastic anemia
May require BMT (bone marrow transplant)
What is anemia of chronic inflammation
Common result of chronic illnesses -AIDS, RA, SLE, Hodgkin’s, Similar to IDA (microcytic/hypochromic)
What is the pathophysiology behind anemia of chronic inflammation
Theory focuses on macrophage and lymphocyte role in sequestering iron, destroying red cells, chemical suppression of EPO response, inhibited precursor cells, reduced Fe transport
How is anemia due to chronic renal failure is different?
normocytic/normochromic
What is the rule of 3s
Hgb should be roughly 3x the red count, Hct should be roughly 3x the Hgb; if wildly off, re-run CBC, there’s a problem.
What is the Hct
take whole blood spin it down, get a red cell pellet –> Hct is proportion size of the red cell pellet to the whole thing, percentage
What is the RDW
High mean variability in size indicates production of new cells red cell distribution width. Tells you if pt is working hard to pump out excess red cells. Reference range = 11-14.5;
What is PLT
platelets, ability to clotting
What is MCV
mean corpuscular volume, 80-100 = “normocytic”
What is MCHC
mean corpuscular hgb content, 32-36% reference range (calculation [(hgbx100)/Hct]; Low = hypochromic; High = hyperchromic
What is the normal values of HgB
14-18 men; 12-16 women
What is ferritin
Ferritin is the iron’s form of storage, low ferritin can indicate iron deficiency, while increase ferritin could mean anemia of chronic disease
What is transferrin
Binds free iron to reduce the oxidative damage associated with free iron and to transfer it
What is total iron binding capacity
an indirect way to measure transferrin levels
What lab values indicate iron deficiency anemia`
INC transferrin, INC TIBC, DEC ferritin, DEC serum Fe
What lab values indicate anemia of chronic disease
DEC transferrin, DEC TIBC, iINC ferritin, DEC serum Fe
What test can demonstrate pernicious anemia?
intrinsic factor made in the gut
What is the hallmark of thalassemia
MCV that is low out of proportion to presentation
What happens when you give a pt w normal Fe, Fe supplements?
Terrible GI side effects.
