Nonmalignant Anemia Flashcards
Anemia
- Decrease in proportion of red blood cells
- Reduced oxygen carrying capacity of blood
What is the level of Hgb for symptomatic anemia?
Hgb < 7 g/dL
What is the general causes of anemia?
- Decreased RBC production
- Increased RBC destruction
- Blood loss
What is the mechanism of anemia?
- Increased destruction – blood loss acute or chronic in surgery, trauma, hemorrhage, menses
- Hemolytic anemia – autoimmune, infectious, hereditary like sickle cell, G6PD
- Deficient or defective erythropoiesis
What are some signs of anemia?
- Weakness
- Tiredness
- Lethargy
- Restless legs
- SOB esp exertional
- Chest pain, reduced exercise tolerance with severe dis
- PICA
- Mild anemia without sx
What are the symptoms of anemia?
- Skin cool to touch
- Tachypnea & Hypotension (severe)
- Pale conjunctiva
- Jaundice (hemolysis)
- Glossitis, cheilitis (iron, folate, B12)
- Splenomegaly (hemolysis)
- Hepatomegaly (alcohol)
- Tachycardia, murmur
- Decreased perception of vibration B12
- Rectal bleeding
Lab levels of Hemoglobin
- Male: 13.5-17.5
- female: 12.0-16.0 g/dL
Lab levels of Hematocrit (Hct)
Actual volume of RBCs in unit volume of whole blood
* Male: 41-53%
* female: 36%
Lab levels of Absolute Reticulocyte Count
indirect assessment of new RBC production: 0.5-1.5%
* Value > 2% suggests hemolysis or acute blood loss
Lab levels of Mean Corpuscular Volume (MCV)
Average volume of RBCs: 80-100
1.
Lab level of Mean Corpuscular Hemoglobin
% volume of hemoglobin in RBC: 26-34
* Reflects the adequacy of iron supply to developing erythron
What is the absorption of ferrous (Fe2+) form?
- Standard western diet ~ 12-15 mg of iron mainly in the ferric (Fe3+) non-absorbed form
- Ferric iron (Fe3+) ionized by stomach acid, reduced to ferrous (Fe2+) form
- Primarily absorbed in the duodenum via intestinal mucosal cell uptake
- Subsequently transferred across the cell into the plasma
Who are the highest risk group for Iron Deficiency Anemia?
- Children < 2 years
- Adolescent girls
- Pregnant females
- Elderly > 65 years
- Malabsorptive syndromes
- Diet
- Blood loss
What is the iron dietary allowance for menstruating females?
18 mg
What is the iron dietary allowance for pregnant females?
27 mg
Reference range of serum iron
- Male: 50-160
- Female: 40-150
Reference range of serum ferritin
- Male: 15-200
- Female: 12-150
What is the oral treatment of Iron Deficiency Anemia?
65 mg of elemental iron once every other day or on Monday, Wednesday, and Friday
* Older adult: Lower doses (15 to 50 mg elemental iron/day)
What are some notable counseling for oral elemental iron?
- GI effects metallic taste, N/V (#2), constipation (#1), diarrhea (#3)
-Tolerance improves with small initial dose, gradual escalation to full dose, new dosing strategy - Administration at least 1 hour before meals
-May take with food if the patient experiences nausea
What are drugs that decrease iron absorption?
- Al-, Mg-, Ca2+ anatacids
- Tetracycline and doxycycline
- Histamine2 antagonists
- Proton pump inhibitor
- Cholestyramine
When are IV iron products preferred?
- Poor GI absorption
- Lack of response to or poor tolerability or oral iron
- Chronic kidney disease
- Active inflammatory bowel disease
- Chronic or extensive blood loss
- Gastric bypass
What are some drugs that are affected by iron?
- Levodopa DECREASE (chelates with iron)
- Methyldopa DECREASE (decreases efficacy of methyldopa)
- Levothyroxine DECREASE (decreased efficacy of levothyroxine)
- Penicillamine DECREASES (chelates with iron)
- Fluoroquinolones DECREASES (forms ferric ion-quinolone complex)
- Tetracycline/doxycycline DECREASE (when within 2 hours of iron salt)
- Mycophenolate DECREASES (decreased absorption)
What is the equation for the total replacement dose (mg of iron)?
0.6 x wt (kg) x [100 – (actual hemoglobin/12 x 100)]
What are some monitoring parameters of Iron Deficiency Anemia?
Reticulocytosis in 7-10 days, Resolution of anemia by 6-8 weeks
Megaloblastic Anemia
- Macrocytosis caused by abnormal DNA metabolism resulting from vitamin B12 or folate deficiency
- Results from interference with folic acid and vitamin B12 interdependent nucleic acid synthesis in the immature erythrocyte
- Rate of RNA & cytoplasm production exceeds the rate of DNA production
- Results in immature, large RBCs or macrocytosis
What is the absorption of vitamin B12?
- Dietary cobalamin enters the stomach
- Pepsin and hydrochloric acid release cobalamin from animal proteins
- Cobalamin binds to R-protein to form cobalamin-R-protein complexes
- Pancreatic enzymes degrade biliary and dietary cobalamin-R-protein complexes releasing free cobalamin
- Cobalamin then binds with intrinsic factor
What are some risk factors for Vitamin B12 deficiency anemia?
- Inadequate absorption
- Perniccious anemia - absence of intrinsic factor
- Cobalamin malabsorption
What can lead to pernicious anemia?
- Autoimmune destruction of gastric parietal cells
- Atrophy of gastric mucosa
- Stomach surgery included gastric bypass
- Europeans of northern descent
- African Americans
- Rare under age 35
What leads to cobalamin malasorption?
- Inability of vitamin B12 to be cleaved and released from proteins in food
- Due to inadequate gastric acid production
- Subtotal gastritis leading to decreased acid pepsin production
- Prolonged use of acid suppression therapy (PPI, H2RA), metformin
What are some neurologic findings of Vitamin B12 Deficiency Anemia?
- Numbness
- Paresthesias
- Peripheral neuropathy
- Ataxia
- Diminished vibratory sense
- Decreased proprioception
- Imbalance
- Vision changes
- Psychiatric changes
What are some symptoms of Vitamin B12 Deficiency Anemia?
- Glossitis
- Muscle weakness
- Decreased exercise tolerance
- Fatigue
- Dizziness
- Irritability
- Weakness
- Palpitations
- Vertigo
What is the treatment regimen for Vitamin B12 Deficiency?
IM vitamin B12:
* 1,000 mcg daily for 1 week
* Then, 1,000 mcg weekly for 1 month
* Then, monthly thereafter
Oral vitamin B12:
* 1-2 mg daily
What is the normal folic acid content of the body?
5-10 mg
Neural tube defects prevention
- All women should take 0.4 mg folic acid daily beginning 1 month pre-conception
- Increase to 4 mg/day if previous NTD pregnancy
What are some risk factors of folic acid deficiency?
- Eating habits
- Malabsorption syndromes
- Hyperutilization - Pregnancy and hemolytic anemia
What are some folic acid deficiency lab test?
- Mean Corpuscular Volume (MCV) > 100 – Macrocytic
- Folic acid
- Decreased serum folic acid levels indicate folic acid deficiency anemia
- Erythrocyte folic acid level less volatile than serum levels
- Reference range (ng/mL): 3-20
What is the treatment regimen forr folic acid deficiency?
- 1 mg daily in most cases
- 1-5 mg daily in cases of malabsorption
- 500 mcg with anticonvulsants drugs
