Anemias - H/O Flashcards
Anemia Intro
- Hematopoesis: the process of making of formed elements in the blood (90% water, 10% solute)
- Occurs in the bone marrow after birth, liver & spleen in utero
- RBCs provide O2 to the tissues
- Core causes of anemia
1. Increased destruction of red blood cells (RBCs)
2. Decreased production
3. Blood loss
Anemia=level hb (WHO)
- Males < 13 g/dL
- Females <12 g/dL
Microcytic
Iron Deficiency
Thalassemias
Anemia of Chronic Disease (ACD)
Normocytic
ACD
Early Fe deficiency
Renal failure
Macrocytic
B12
Folic acid
Liver disease
Hypothyroid
Hypochromic
(RBC color)
Iron deficiency
Low hgb amount in each cell
Low MCH (mean cell hgb; average content of hgb per RBC)
Low MCHC (mean cell hgb concentration, average volume of hgb in a given volume of packed RBCs)
Symptoms/Signs of Anemia
Symptoms
- Asymptomatic
- Weakness
- Headache, dizziness
- Palpitations
- Exercise Intolerance due to SOB
- Dyspnea
- Claudication
Signs
- Pallor (skin, oral mucosa, conjunctiva, palms)
- Jaundice (hemolytic)
- Tachycardia, tachypnea
- Edema
- Ecchymosis, petechiae: Platelet dysfunction
- ACUTE VS CHRONIC
- Acute: more severe sxs
- Chronic: more gradual onset and therefore less severe sxs
Iron Deficiency
Pathophysiology
- Microcytic, hypochromic anemia
- Iron helps make hgb functional
- Max absorption in duodenum, decreased in proximal jejunum
Epidemiology: Most common type of anemia US (CDC 2013)
- 9% of the overall US population, MC Females & children <2
- Children 1-2 yo: 14%
- Females 12-49 yo: 9%
Risk Factors
-Early childhood, adolescence, pregnancy, menses/blood loss, renal disease, impaired absorption, chronic alcoholism, poor nutrition
Iron Deficiency - dx
Etiology
- Blood loss (e.g. menorrhagia, gastric ulcers)
- increased demand (growth, pregnancy)
- decreased iron absorption, decreased iron intake, celiac disease, gastric bypass or morbid obesity
Presentation
- Pica: craving for non-edible substances (e.g clay, dirt, ice, paper products, or starch)
- Severe chronic deficiency: Plummer-Vinson Syndrome
- Brittle nails, cheilosis, smooth tongue, esophageal webs
Diagnosis
- Microcytic (MCV < 75), Hypochromic on smear
- Hgb < 13 males, <12 in females,
- Labs: CBC, serum iron, ferritin
Iron deficiency labs
- decreased Hgb (Normal: 12-16 Fem, 13-17.5 g/dL- Male)
- decreased Hematocrit (35-50%)
- decreased MCV –Microcytic (80-100fL)
- decreased MCHC- Hypochromic (31-37%)
- decreased Ferritin (15-150 ng/mL) - a protein that helps store iron
- increased TIBC -Total iron binding capacity (250-400 mcg/dL), TIBC: Indirect measure of free transferrin (no Fe), Transferrin: Protein that carries iron in the blood
- decreased Total serum iron (50-150 mcg/dL) –Amount of iron in blood
- Reticulocyte count (0.5-1.5 nl)
- Stool sample looking for occult blood
Fe Deficiency Management
-Differential Dx: Thalassemia, ACD
Management of Anemia
- Find underlying cause (Fe will not work if not Fe def)
- Iron vs dietary supplementation
- Recheck hgb q 4 weeks until normal, sooner is not as useful unless worried of worsening hgb
Diet
-RDA 8mg men; 18mg women
-Heme iron in meat, fish, poultry is absorbed 3x that of
non-heme iron in veggies, supplements
-Iron hearty food: see above, broccoli, raw tofu, Total cereal, lentils
Fe Replacement
-Ferrous gluconate : 325mg tid
-Fe sulfate 325 (65mg elemental iron), Fe fumarate 325 (107), Fe gluconate 325 (39)
-200mg of elemental iron daily in 2-3 divided doses/day
-If intolerable due to AE, decrease dose by half
-If tolerating-should see increase by 2-4 g/dL q 3-4 weeks
-Parenteral Iron-via IV for those unable
to tolerate PO Fe or with chronic profound losses
-Continue Fe therapy x 3-6 months after normal hgb/hct to replete tissue stores
-Acute bleed-one month
Fe deficiency - education
-Adherence is important to stress given likelihood for AE
-Peds: delay of motor or mental function
-Pregnancy: risk for small or preterm baby with risk of health problems
-Teens: memory, mental function decreased
Iron supplementation:
-Empty stomach with vitamin C. Avoid taking with coffee, tea. Food decreases absorption by 50%
-Breast fed babies—Fe fortified cereal after 6 m.o.
Potential AE of Fe:
-Nausea, GI upset, stools may be black and tarry, constipation
B12 Deficiency Anemia
Pathophysiology
- Cobalamin=Vitamin B12, Macrocytic (MCV > 100)
- Water soluble, stored in the liver
- Maintains CNS function, several biochemical functions, and needed for DNA synthesis
- Max absorption in stomach and terminal ileum
- Humans cannot make B12-MUST be consumed regularly
- Comes from animal proteins: beef, poultry, fish, eggs, & dairy
- Unfortified plant-based foods do not contain vitamin B12
Epidemiology
- MC in older adults >51 yo (1/31 individuals)
- Atrophic gastritis and pernicious anemia MC in elderly
Risk Factors
- Cohn’s, gastric bypass surgery, pernicious anemia, vegan, strict vegetarian diet
- Pernicious anemia : Chronic atrophic gastritis– Decreased production of IF (Intrinsic factor), Autoimmune– Antibodies attack gastric cells -> impaired production of IF that is critical for absorption of vitamin B12
Etiology
-Inadequate intake, malabsorption (IF deficiency, PPIs, H2 blockers), Inadequate utilization
B12 deficiency - signs, sxs, dx
Presentation/symptoms
- Glossitis, dysphagia
- Neurologic: Peripheral neuropathy, paresthesias, irritability, dementia, depression, ataxia, and weakness
- If neuro sxs present > 6 months decreases chance of reversibility
Diagnosis
- Labs: Serum cobalamin, CBC, peripheral smear
- Low serum B12 (nl 100-900), +/- low hb
- Peripheral smear: macrocytosis with hypersegmented polymorphonuclear leukocytes
- May have falsely normal serum B12 in presence of liver disease, myeloproliferative disorders, and renal insufficiency—f/u on sxs!
B12 Deficiency - Management
-Patient education, generally well tolerated, normalizing hgb within one week
-Recheck CBC and B12 level after 1-2 months after tx start and again 3-6 months to ensure stable levels
pElderly with malabsorption-need lifelong tx!
-Iron demands may decrease due to erythropoiesis
PO Vitamin B12
- Preferred for mild, moderate anemia, & maintenance
- 1-2 mg (1,000-2,000 mcg) PO daily
- 1% of PO doses of vitamin absorbed in small intestine
Parenteral (IM)
- 1000 mcg daily x 1 week, then 1000mcg q week x 1 month, then 1000 mcg q month
- Requires office visit. Consider if severe B12 deficiency or neuro sxs, vomiting, diarrhea, bowel resection
Nasal Spray
- Absorption erratic, limited data, $$$
B12 Deficiency Management - education/diet
- Generally supplementation is well tolerated
- Possible AE (rare) : hypokalemia, hyperuricemia, sodium retention, rebound thrombocytosis
- If needing lifelong tx due to malabsorption, Prep the pt for this!
Diet
- RDA B12: 2.4 micrograms daily for adults
- Fish, poultry, beef, dairy
B12 Must Knows!
1) Vitamin B12 deficiencies occur in adults 51 years of age or older at a frequency of 1 (3.2%) in every 31 persons, and manifest as serum vitamin B12 levels below the cutpoint of 200 pg/mL.
2) All patients with unexplained hematologic or neurologic signs or symptoms should be evaluated for a vitamin B12 deficiency. If found, the cause should be determined.
3) Today, megaloblastic anemia is most likely due to vitamin B12 deficiency and needs prompt evaluation. In the United States, folic acid fortification has made folate deficient megaloblastic (macrocytic) anemia a very rare condition.
4) Although the body’s ability to absorb naturally occurring vitamin B12 decreases with age, most people can readily use the synthetic form of cobalamin.
5) All people 51 years of age and older should get most of their daily vitamin B12 through supplements containing vitamin B12 or foods fortified with vitamin B12.
Folic Acid Deficiency Anemia
Pathophysiology: Macrocytic
- Water soluble and heat labile
- Found in green leafy vegetables, fruits
- Folic acid= synthetic form of folate
- Absorbed in proximal 3rd of small of intestine
- Necessary for production of nucleic acids, proteins, amino acids as well as DNA synthesis
Epidemiology
< 1% of US population -down from 10-12%, Why??
-1998 FDA mandated fortification in cereal products
Risk Factors
- Alcoholism, malnutrition
- Alcohol directly interferes with erythropoiesis as well as decreased absorption of folic acid
Etiology
- Decreased dietary intake, Increased usage (hemolytic anemia), Decreased absorption
- Medications: Folate antagonists: methotrexate, trimethoprim, triamterene
Folic Acid Deficiency Anemia - sxs, dx
Presentation
-No neurologic sxs, general sxs of anemia, fatigue, HA
Diagnosis
-Macrocytic anemia, decreased serum folate
Management
- Symptomatic improvement is within 1-2 weeks
- Hgb should normalize within 2 months
FA Deficiency Management
Medication Management
-PO folic acid 1-5mg PO daily x 4 months
Patient education
- Should be educated on dietary needs
- Neural tube defects in pregnancy
- Breastfeeding mothers should continue PNV while breastfeeding
- 3 month prior to pregnancy take PNV or folic acid to build stores
Diet
-RDA is 4 mg daily, 6 mg in pregnancy
Anemia of Chronic Diseases (ACD)
Pathophysiology
- Infectious, inflammatory, or neoplastic disease that is more than 6-8 weeks
- During chronic disease, RBC lifespan is shortened
- May be release of cytokines during illness that inhibit RBC production
Risk Factors and potential etiologies
- Any chronic disease that puts physiologic stress on the body
- Infections: Osteomyelitis, HIV, hepatitis
- Autoimmune disease: SLE, RA
Anemia of Chronic Diseases (ACD) - sxs, dx
Presentation
- Symptoms of anemia
- May be combined with sxs of underlying disease
Diagnosis
- Rule out other treatable forms of anemia
- Labs, studies, focused exam based on pt’s sxs that may lead to underlying disease dx
Management
- Will improve with improvement of underlying disease
- Rarely severe enough to need transfusion