Q4 Heme Flashcards
Loss of plasma can cause a falsely ______ Hgb/Hct, and excess plasma/fluids can cause a falsely _______ Hgb/Hct.
Elevated
Decresed
Anemia definition in M and F
F = Hgb <11.9 and Hct <35%
M = <13.6 and <40%
What are the 4 main pathologies of anemia?
Blood loss (bleeding/hemorrhage)
Impaired erythrocyte production
Increased “ breakdown
Combination of these 3 factors.
What is the normal SaO2 and SvO2 concentration and % offloaded at tissues?
SaO2 (arterial leaving lungs) is usuallly 100% and then SvO2, returning TO lungs is usually ~75% - usually ~ 24% offload.
How does the body compensate for anemia?
??
Dilation of peripheral vessels to decrease SVR (increased NO). This increases CO through decreasing after load and increasing the PREload through increased venous return. Heart rate and contractility increases.
When the volume of RBCs decreases, there is an increased in velocity.
Decreases fluid viscosity for faster flow.
Increased HR and SV (SNS Stim via chemoreceptors to hypoxia)
Increased RR and depth.
Activation of RAAS - Na and H2O retention and more erythropoietin.
What changes happen to the heart in chronic anemia?
LV hypertorphy and valvular dysfunction.
As CO/Hgb decreases, DO2 (delivery of O2 to the tissues) ________
As CO/Hgb decreases, arterial saturation ______
As CO/Hgb decreases, Mixed venous sat _______
As CO/HGB decreases, O2 extraction ratio (%) _______
Decreases
Decreases
Decreases
Increases
When you have a L shift, there is _____ temp, 2,3DPG, H+ and CO. Blood is more _________ (Acidotic/basic). There is a natural L-shift in the ______ and the RBC holds _____ affinity to O2.
When there is a R shift, Temp, 2,3GPD, H+ ______. Blood is more _____. A natural R shift occurs in _____ where RBC holds _____ affinity to O2.
Decrease
Basic (Decrease in H+)
Lungs
More
Increase
Acidotic (increase in H+)
Tissues
Less
Patients who are altitude acclimated have a natural ____ shift and increased _____.
Right
2,3DPG
This means they easily release O2 to the tissues so they can survive in low O2 environments.
The amount of O2 that dissolves in plasma is ________. Why is this important?
VERY LOW. This means we need Hgb to carry it to the tissues. If we are low in Hgb, the O2 can’t get to the tissues any other way.
What does Anisocytosis mean?
A high degree of anisocytosis means there is a lot of variability between cell sizes
A low degree of anisocytosis means there is not much variability, all cells are mostly the same size.
Another term for this is RDW.
What does it mean if someone has a low MCV?
MCH?
MCV is average size of RBCs.
Low MCV means microcytic.
MCH is mean corpuscular hemoglobin or average Hgb content in an RBC.
Iron Deficiency Anemia (IDA) is _____cytic and _____chromic.
___ MCV
___ MCH/MCHC
____ RDW
MICROcytic/HYPOchromic.
Low
Low
Variable
Pernicious Anemia
___ MCV (____Cytic)
____ MCH/MCHC
____RDW
HIGH - MACRO
Variable (usually normal)
Variable (usually high)
For pernicious anemia, DNA is not able to split (deficiency in components) so cells get stuck, but the cytocytic content gets bigger while waiting for cell to split.
Initial fluid replacement for Class I, II, III and IV hemorrhage?
I - crystalloid
II - Crystalloid (750-1500ml)
III+IV - Crystalloid and blood. (1500->2000ml).
3 major types of anemia involving low production of Erythrocytes.
Megaloblastic (Macrocytic/Normochromic) Anemia (PA, Folate deficiency anemia and medication related)
Microcytic/HYPOchromic Anemias (IDA)
Normocytic/normochromic (anemia of chronic disease, aplastic anemia)
Patho Phys of Megaloblastic (macrocytic-normochromic) anemia
Vit B12/IF (PA) and Folate are needed to perform DNA synthesis. When they are absent, the cell takes longer than normal to divide. These then larger than normal cells die prematurely.
What does Vit B12 (cobalamin) do?
It works with methionine synthase to activate folate for Neucleic acid synthesis.
5.10 Methylene TH4
Folate is Vit ____
B9
B9 and B12 are found exclusively in ____
Foods.
B12 mostly in foods of animal origin.
2 causes of B12 deficiency
Lack of dietary intake (Vegans)
Pernicious anemia (lack of IF and ability to properly absorb B12)
Key difference between folate (B9) deficiency and B12 deficiency is:
B12 has anemia AND neurological symptoms due to demyelination (peripheral neuropathy)
Two types of PA
Congenital - IF deficiency. B12 must bind with IF in order to be absorbed in the GI tract.
Autoimmune - gastritis - destroys parietal cells that create IF.
If someone has macrocytic-normochromic erythrocytes on smear, what anemias could they have?
PA, Vit B12 or Folate deficiency anemia
What is the only way to distinguish vit B12 deficiency r/t dietary deficiency or issues with absorption?
Gastric biopsy.
Would oral B12 supplementation be an adequate tx for PA? Why or why. Not?
No. Because in PA, IF is lacking, so B12 cannot be absorbed through the GI tract. It must be given as a shot.
What chronic illnesses could lead to vit B9 (folate) deficiency?
Alcoholism (interferes with folate metab in liver)
Celiac disease and
IBD
Pregnancy
What is an example of microcytic-HYPOchromic anemia?
IDA.
What type of anemia is IDA?
Microcytic-HYPOchromic
What is the most common nutritional deficiency in the world?
IDA
4 causes of IDA
Dietary deficiency
Impaired absorption
Increased requirement
Chronic blood loss
Iron is needed for____
Hgb synthesis.
What stage of IDA do symptoms appear?
Stage 3 - when the microcytic/HYPOchromic erythrocytes are released into circulation and replace normal onesie.
Which lab tests can show iron storage values?
Serum ferritin or transferrin
T/F; Iron replacement therapy corrects IDA right away.
False. Usually takes abut 1-2mmonths to see effects.
What type of anemia is common in hospitalized individuals?
4 main causes?
Anemia of chronic disease (normocytic/normochromic)
Infections
Cancer
Autoimmune (RA, SLE, IBD)
CDK/Inflammatioin
Someone with RA or solid tumor cancer or CKD is most likely to develop which anemia?
Anemia of chronic disease.
What causes the anemia in anemia of chronic disease?
Decreased erythropoietin production from stressed kidneys
Impaired iron utilization - sequestered in macrophages - IL6 decreases activity of the pump that allows iron back out into circulation when needed.
RBCs die prematurely
Decreased response of bone marrow to erythropoietin
What does it mean to have “sequestered” iron? How does chronic disease affect this?
Used iron normally circulates until it is picked up and stored by machrophages until needed again. Macrophages have ferroportin transporters that release iron back into the blood stream when it’s needed again. During inflammatory states, IL-6 causes an increase in hepatocyte hepcidin secretion. Hepcidin decreases the Ferroportin pump activity leaving the iron molecules in the macrophage. Iron levels will appear normal, but they are “sequestered” in the macrophage and not in circulation where it can be used.