Therapeutics Exam 3 (Anemia) Flashcards
What is anemia?
Decrease in red blood cells or hemoglobin (the piece of RBC that carries oxygen)
How do I know if my patient has anemia?
Hemoglobin levels
-signs and symptoms
-bloodwork
What are the symptoms of anemia?
-Exertional dyspnea (SOB) [not enough oxygen to body]
-Angina [not enough oxygen to the heart]
-Tachycardia [heart tries to compensate for lack of oxygen by pumping out more blood]
-Fatigue
-Pallor (paleness)
*Could be asymptomatic, especially if it occurs slowly and the body compensates
What is hemoglobin?
The oxygen carrying capacity of RBC’s
What is a normal hemoglobin range?
Men: 13.5-18 g/dL
Women: 12-15 g/dL
What is mean corpuscular volume (MCV)?
The average volume of RBCs
What is a normal mean corpuscular volume (MCV)?
80-100 mm^3
True or False: Iron supplementation is the first line treatment of anemia
Not always!
-Treating with iron will only work if the patient has iron deficient anemia (the most common type of anemia)
What are the causes of anemia?
Not making enough RBCs
Body is destroying RBCs too quickly
Loss of RBCs
What could cause decreased RBC production?
Chronic diseases (chronic kidney disease, cancer, CHF)
Nutritional deficiency (iron, folic acid, vitamin B12)
What could cause increased RBC destruction?
Drugs
Sickle cell anemia/Thalassemia
What could cause increased RBC loss?
Acute blood loss
Chronic NSAID/ASA use
A microcytic RBC has a MCV of what?
<80
(small)
A normocytic RBC has a MCV of what?
80-100
(normal)
A macrocytic RBC has a MCV of what?
> 100
(large)
What types of anemia are characterized by microcytic RBC’s?
Iron deficiency
Sickle cell
Thalassemia
What types of anemia are characterized by normocytic RBC’s?
Anemia of chronic disease
Blood loss
Hemolysis
What types of anemia are characterized by macrocytic RBC’s?
Folic acid deficiency
B12 deficiency
What are the consequences of anemia?
Impaired cognitive function
Falls
Heart failure
Atrial fibrillation
Cardiovascular events
Mortality
What is the most common type of anemia?
Iron deficiency anemia
What are the defining lab values of Iron Deficiency Anemia?
Hgb- low
MCV- low
**Ferritin- low
**Transferrin saturation (TSAT)- low
What is ferritin?
Indicator of iron stores
-acute phase reactant, is elevated in acute inflammation or chronic disease
-can look higher in hospitalized patients
What are the normal values of Ferritin?
15-200 ng/mL
*iron deficiency can still occur when ferritin <45 ng/mL
What is TSAT (transferrin saturation)?
Amount of iron ready for erythropoiesis
What is the normal value for TSAT (Transferrin saturation)?
20-50%
What are the causes of iron deficiency?
Blood loss (menstruation, blood donation)
Decreased absorption (celiac disease, gastric bypass)
Vegetarian diet
Increased consumption (pregnancy)
Not normally drug induced
What are the symptoms of iron deficiency anemia?
Spoon-shaped nails
Inflamed tongue
Pica (craving substances with no nutritional value)
How do we treat iron deficiency anemia?
Give patient iron
-Oral is preferred over IV
-Exceptions to oral:
–Not tolerated
–Not absorbed
–End stage renal disease
–Heart failure
How much iron is found in ferrous sulfate?
65 mg elemental iron
What is the normal amount of iron we will give a patient?
65 mg elemental iron every other day
(ferrous sulfate every other day)
How long does it take to replete iron stores?
3-6 months
Why is every other day dosing better than daily when it comes to iron?
Hepcidin
-this is an iron-regulating peptide hormone released by the body every time you take a dose of oral iron
-hepcidin decreases oral iron absorption
-therefor, waiting a day before giving the next dose will avoid the hepcidin and ultimately give you the same response as once daily dosing
-every other day dosing is also better tolerated
What are the counseling points for iron?
-Increased absorption when taken on empty stomach
-Vitamin C increases absorption (ascorbic acid)
-Causes constipation
-Causes dark stools
-Take 2 hours after PPI because they interfere with absorption
What are the indications for IV iron?
End stage renal disease
Heart failure
Failed oral iron
Malabsorption
What are the side effects for IV iron?
Hypotension
Skin tattooing
What are the defining factors of a Vitamin B12 deficiency?
Hgb- low
MCV- high
***Serum B12- low (<200)
What B12 level is considered low?
<200
What are the causes of Vitamin B12 deficiency?
Diet related!
-Vegan/Vegetarian
-Alcoholism
Lack of intrinsic factor (pernicious anemia, cannot absorb B12)
Decreased absorption
Medication (PPI’s, Metformin)
What are the consequences of B12 deficiency?
Neurologic symptoms
(weakness, numbness, cognitive dysfunction)
How do we treat B12 deficiency anemia?
B12 supplements
-oral or IM/SC injections
What is the typical dosing regimen for IM/SC B12?
Daily for 1-2 weeks, then monthly, then periodically
When using an oral regimen, how much B12 should a patient get per day?
1000-2000 mcg/day
What are the defining factors of a folic acid deficiency?
Hgb- low
MCV- high
**Serum folate- Low (<5 ng/mL)
What is considered a low serum folate?
<5 ng/mL
*also can consider <10
What are the causes of folic acid deficiency?
Malabsorption
Malnutrition
Alcoholism
Medications (methotrexate, phenytoin, sulfasalazine, sulfamethoxazole/trimethoprim)
How do you treat folic acid deficiency anemia?
Oral folic acid supplementation
How much oral folic acid should a patient receive per day?
1-5mg daily until Hgb normalizes
You should never replace folic acid without doing what?
Checking B12 first
-folic acid supplements can correct the anemia but the neurological deficits of vitamin B12 deficiency will remain
How can chronic kidney disease cause anemia?
-Erythropoietin is produced in the kidneys
Anemia occurs because of:
-Decreased erythropoietin production
-Chronic inflammatory state causing anemia of chronic disease
-Nutritional deficiencies
How do you treat anemia of chronic disease?
Generally just need to treat the chronic disease well
How do you treat anemia in chronic kidney disease?
-Avoid blood transfusions
-Correct nutritional deficiencies
-oral iron in stage 3-5 if possible
-IV iron in hemodialysis
-Target transferrin saturation is above 30%
-Erythropoiesis stimulating agents (erythropoietin, darbapoietin)
What is the target TSAT (Transferrin saturation) in chronic kidney disease?
above 30%
*go a little bit higher than 20% minimum in these patients
What are our target hemoglobin levels in chronic kidney disease?
We do not target normal hemoglobin levels when using ESA’s!!!
-this increases MI risk
*Goal is just to keep Hgb above 10
HOWEVER: we DO target normal levels when giving iron supplementation
When can we start erythropoietin stimulating agents (erythropoietin, darbapoietin) in anemia of chronic kidney disease?
Only after replenishing iron stores
How do we treat anemia caused by heart failure?
-Patients may benefit from IV iron if:
-iron deficiency (ferritin <100, or 100-300 if TSAT <20%)
*note that ferritin targets are higher due to state of inflammation
What form of iron should be used in heart failure anemia patients?
IV only! -although it has not been shown to improve survival
*oral iron has shown no benefit
What drug class should be avoided in heart failure associated anemia?
Erythropoietin stimulating agents
**these are harmful for HF patients
For blood loss anemia, at what Hgb level do we give packed red blood cell transfusions?
Hgb < 7
