Approach to the adult patient with anemia- Lecture 2 Flashcards
What are the 4 steps in the process of erythropoiesis
- low O2 delivery
- EPO stimulation
- RBC proliferation and maturation
- Reticulocyte release
What is flow of an RBC formation
EPO binds to _______. What does it induce?
marrow erythroid precursors
induces cell maturation
What are marrow erythroid precursors called?
proerythroblasts
____ and _____ are needed to assist with proliferation of RBC
folate and Vit B12
_____ assists in the accumulation of hemoglobin
iron
what is the role of iron?
binds oxygen to hgb
Describe the process of erythropoiesis. What do all the stars mean?
Name two differentiating factors of reticulocytes as compared to RBC
NOT biconcave (more round)
slightly bluer than RBC
T/F: Reticulocytes contain RNA and RBC do not
true
What is the total life span of a reticulocyte?
4-5 days
3 days in bone marrow
1-2 days in blood
What are the optimal conditions for erythropoiesis?
normal EPO production
Normal erythroid marrow function
Adequate Hgb accumulation
What is the end result if any of the physiological processes become defective during erythropoiesis?
decreased RBC production
_____ is considered a reduction of one or more of the major red blood cell measurements, what are they?
anemia
Hgb
Hct
RBC
What kind of approach includes addresses the mechanism responsible for the fall in hemoglobin concentration
Kinetic approach to anemia
What kind of approach includes categorizes anemias based on alterations in RBC characteristics and the reticulocyte response?
Morphologic approach to anemia
The kinetic approach address the _____ responsible for the fall in hemoglobin concentration
mechanism
Morphologic approach: categorizes anemias based on alterations in ______ and the _______
RBC characteristics
reticulocyte response
the kinetic approach to anemia can be caused by one or more of these things, name them.
decreased RBC production (erythropoiesis)
increased RBC destruction (hemolysis)
blood loss
T/F: Under steady state conditions, there is more RBC being produced than RBC being destroyed
FALSE, production = destruction
on average, what is the daily production of RBC?
1% of red cell mass
What are the 5 common causes for decreased RBC production
- Lack of nutrients (iron, B12, folate)
- bone marrow disorders
- bone marrow suppression
- low levels of trophic hormones
- acute/chronic inflammation
What are the 3 reasons for increased RBC destruction
- inherited hemolytic anemias
- acquired hemolytic anemias
- hypersplenism
What is the most common cause of anemia?
blood loss
What are the 4 types of blood loss?
- gross blood loss
- occult blood loss
- iatrogenic blood loss
- under appreciated menstrual blood loss
If you damage your bone marrow, what happens to the reticulocyte count?
retic count decreases
what happens to the retic count when you have blood loss?
retic count increases
what happens to the retic count when you have increased RBC destruction?
retic count increases
the morphologic approach classifies anemias based on ????
red cell indices (MCV, MCH, MCHC)
reticulocytosis will (increase/decrease) MCV
increase
What are some causes of macrocytic anemia?
-folate and B12 deficiency
-drugs that interfere with nucleic acid synthesis
-abnormal RBC maturation
-alcohol abuse
-liver disease results in lipid deposits on RBC increasing surface area
microcytic anemia is often associated with low MCHC due to ____ hgb content in the small RBC
low/decreased
What is most common cause of microcytic anemia?
iron deficiency**
alpha or beta thalassemia minor
How is normocytic anemia diagnosed?
with a peripheral smear
What are causes of normocytic anemia?
Chronic kidney disease
anemia of chronic disease/inflammation
mild iatrogenic hospital anemia
Name some causes of mild iatrogenic hospital anemia
recurrent venipuncture, blood loss from surgery, hemodilution with IV fluids, blunted erythropoiesis due to acute illness
Physiology of anemic symptoms is directly related to ????
decreased oxygen delivery to tissues
acute, moderate-severe blood loss will also cause _____ and a more severe clinical presentation of anemia
hypovolemia
How does the body compensate for anemia?
increase in oxygen extraction
increase in stroke volume and heart rate
symptoms occurring at rest indicate a ______ or the heart’s inability to compensate
lower Hbg and Hct
What are the common s/s associated with an anemic patient
varying degrees of fatigue
unusual exertional tachycardia/dyspnea
tachycardia/dyspnea at rest
palpitations
audible pulsations
bounding pulses
pallor
Name some signs of anemia complicated by volume depletion
easy fatigability
muscle cramps
dizziness/syncope
lethargy
progressive hypotension/shock/death
What are the 4 major questions you should ask yourself when considering a anemia patient.
-Is the patient bleeding (past or present)? If so where?
-Is there evidence of increased RBC destruction (intravascular or extravascular)?
-Is there bone marrow suppression? If so why?
-Is the patient nutrient deficient in iron, folate or B12? If so why?
Name some constitutional symptoms.
unintentional weight loss, loss of appetite, fever, night sweats
symptoms of hx of medical condition associated with anemia
Melena - Upper GI bleed, bleeding ulcer
Large hematochezia - Lower acute GI bleed
Menorrhagia - Dysfunctional uterine bleeding
Renal failure
Rheumatoid arthritis
CHF¹
Name some social hxs approach that points to anemia
alcohol, asa, nsaids, blood thinners
Describe the skin of an anemic pt
pallor, jaundice, petechiae, bruising
describe the eyes of an anemic pt
pale conjunctiva, scleral icterus
Name some additional physical exam findings commonly found in anemic patients
lymph nodes
Hepatosplenomegaly (HSM)
bony tenderness (sternum, anterior tibia)
stool for occult blood
Consider looking at this flow sheet, maybe?
Hgb, hct and RBC count are all concentrations and dependent on _____
red cell mass
If RCM is decreased and/or plasma volume is increased, what are the RBC and H&H doing?
RBC and Hgb and Hct will be low
If plasma volume is decreased, what are RBC and H&H doing?
RBC and H&H will be elevated
How is retic count reported?
reported as a percentage of RBC
Why might the retic count be a problem when evaluating an anemic patient?
fewer RBC which may falsely increase the retic count
What is the most accurate way to count reticulocytes in an anemic patient?
retic index calculation
How do you calculate Reticulocyte Index Calculation (RI)? What is normal?
RI= retic percentage x (patient’s HCT/normal HCT)
RI is <3%
Consider maybe looking at this again?
Increased retic count is indicative of ______
hemolysis
Name 3 labs that can help you further evaluate hemolysis?
serum lactate dehydrogenase (LDH)
indirect bilirubin
serum haptoglobin
Destruction of the RBC will (increase/decrease) LDH
increase
How is indirect bilirubin calculated?
Indirect bilirubin (unconjugated= total bilirubin - direct bilirubin (conjugated)
bilirubin is the orange-yellow pigment derived from ???
the breakdown of hgb
______ binds free hgb that is released from hemolyzed RBC
Haptoglobin
What is the coombs test test for?
Assesses the presence of antibodies on the surface of RBC’s, which ultimately causes RBC destruction
What does a positive coombs test indicate?
autoimmune hemolytic anemia, hemolytic transfusion reaction, drug sensitizations, hemolytic disease of the newborn
Is a normal coombs test positive or negative?
negative
Name some lab tests associated with microcytic anemia
Maybe consider looking at this one again??
name 3 ways the human body can lose iron
perspiration
epithelial cell desquamation
menstruation
Where is 65% of iron in the body found?
bound up in hemoglobin molecules in RBCs
Where is 30% of the iron in the body stored?
stored as ferritin or hemosiderin in the spleen, bone marrow and the liver
Where is 4% of the iron in the body found?
bound up in myoglobin molecules
Where is < 1% of iron in the body found?
throughout the cells in the body
Where is < .1% of the iron in the body is found?
bound to transferrin (taxicab for iron)
What does the serum iron measure?
Measures the amount of circulating iron bound to transferrin
What does decreased serum iron levels indicate?
iron-deficiency anemia, nephrosis¹, anemia of chronic disease and infection, chronic blood loss, malabsorption disorders
What does increased serum iron levels indicate?
hemochromatosis², excessive iron intake, hemolysis of erythrocytes, liver necrosis³
_____ is the major plasma transport protein for iron largely synthesized by the liver
Transferrin
Transferrin carries iron from the _______ to ______
duodenum to the marrow
What does transferrin saturation calculate?
Calculates how much of the transferrin is being bound by iron
What does a decreased transferrin saturation indicate?
iron-deficiency anemia
What does an increased transferrin saturation indicate?
hemochromatosis, iron overload, thalassemia, RBC transfusions
What does the total iron binding capacity measure?
Measures the blood’s capacity to bind iron with transferrin; indirectly measures transferrin
What is the opposite of transferrin saturation?
total iron binding capacity
______ is the body’s major iron storage protein
ferritin
iron molecules not transported to marrow by _____ are bound to _____ for later use
transferrin
ferritin
______ the most reliable indicator of total-body iron status. What is the MOST ACCURATE?
ferritin
bone marrow biospy
______ is more specific and sensitive than iron concentration or TIBC for diagnosing iron-deficiency anemia
ferritin
What things do you need to determine macrocytic anemia?
retic count
B12
folate
Maybe look at this again idk???
Vitamin B12 requires ______ and ______.
Requires intrinsic factor (produced in the stomach) for absorption in the ileum
in order for vitamin b12 to be absorbed normally, what things must be working?
requires a normally functioning stomach, exocrine pancreas, and intestinal mucosa
Where is the majority of vit B12 stored?
stored in the liver
folic acid requires normal functioning of ______ for absorption
intestinal mucosa
Where specifically is folic acid absorbed? Where is it stored?
Absorbed in the upper ⅓ of the intestine and stored in the liver
What do elevated serum folate levels indicate?
B12 deficiency
Name a responsibility of B12
move folate into tissue cells
Maybe consider looking at this again?? who knows?
What is the main cause of microcytic anemia?
iron deficiency
What does transferrin saturation measure?
how much transferrin is bound to iron
What is the pathophysiology behind an anemic patient presenting with jaundice?
hemolysis
What is the significance of the RDW?
acute or chronic
