anemia

what is anemia

• decrease in number of RBCs or too little hemoglobin

• can also include a reduced Hgb binding capacity due to abnormal Hgb

symtoms of anemia

hemoglobin

amount per volume of whole blood

hematocrit

volume of RBCs in unit of whole blood

red blood cell count

number of RBCs per unit of blood

mean corpuscular volume (MCV)

average volume of RBCs; microcytic, normocytic or macrocytic

mean corpuscular hemoglobin

amount of hemoglobin in cell; called hypochromic if low

mean corpuscular hemoglobin concentration (MCHC)

concentration of Hb per volume of cells

reticulocyte count

number of immature (new) cells

red blood cell distribution width (RDW)

greater variation shows greater variability in size of RBCs

iron deficiency anemia causes

• 90 % of IDA is caused by

  • Menstrual blood loss

  • GI blood loss

  • Pregnancy

• Other causes

  • Poor iron absorption

    • Medications

    • Helicobacter pylori

    • GI diseases/surgery

• Insufficient intake is uncommon in adults

• ♂ only 1-2 % of cases

iron tests

• serum iron

• total iron binding capacity

• transferrin saturation

• serum ferritin

serum iron

concentration of iron bound to transferrin

total iron binding capacity

Measures iron binding capacity of transferrin (will increase if iron is low)

transferrin saturation

Ratio of serum iron to TIBC; normal is 20 to 30% but will be lower with iron deficiency

serum ferritin

Measures iron stores; best indicator of iron deficiency

IDA labs

•CBC

• microcytic

• hypochromic

• ↓ MCV

•Fe Studies

• Serum Iron- low

• Serum Ferritin- low

• TIBC- high

• Transferrin Saturation- low

IDA factors affecting absorption

• Best absorption via consumption of meat

• Foods ↑ in Fe

  • blackstrap molasses

  • clams

  • raisin bran cereal

  • turkey (dark meat)

  • red meat

• Absorption can be blocked by coffee, tea, egg yolk, milk, fiber, spinach

iron counseling (dose)

•Oral daily or 3 times weekly

•Best absorbed on empty stomach but may be better tolerated with food

•One form not more effective than another

•Patients may tolerate forms with less elemental iron better

•More iron will not correct anemia faster

•Iron is a pro-oxidant, so too much can be harmful

•Parenteral iron needed in some cases but risk of anaphylaxis

acid-reducing drugs and iron

•Acid-reducing drugs may decrease iron absorption

• Acid-suppressing meds may still be needed for patient

• Key is monitoring

iron and minerals/meds

Potential decreased absorption with minerals/meds

• Ca, Mg, Al

• tetracycline/doxycycline

• take iron 1-2 hours before/4 hours after ideally

• May need to separate differently for patient needs/practical regimen

mineral and med decreasing iron absorption

• Ca, Mg, Al

• tetracycline/doxycycline

response to iron Rx

•Hgb ↑≈ 1 gm/dL per week

•reassess if Hgb not ↑ by 2 g / dL after 3-4 weeks

•May need 6 to 12 months treatment for ferritin to return to normal

anemia of chronic disease underlying causes

• infection cancer

• autoimmune disorders

  • RA

  • SLE

  • inflammatory bowel disease

• CKD

anemia of chronic disease

• 2^nd most common form of anemia

• normochromic normocytic

• characteristically mild to moderate (Hgb- 9.5-8)

• low retics

• may be mixed with IDA

  • microcytes may be present

  • if mixed→anemia tends to be more severe

  • Key is treating underlying condition as much as possible

  • Fe status should be evaluated and Rxed if present

B12 deficiency causes

•80% of cases → Pernicious Anemia (lack intrinsic factor)

•10% of cases → achlorhydria

•B-12 is readily available in most diets and has a long storage time

•3-6 years to run out

B12 deficiency presentation

• yellow pallor

• neuro-findings

  • glove and stocking paresthesias, ↓ vibratory sensation

  • ataxia, spasticity, contractures

  • depression, psychosis, persecutory delusions

• GI- sore beefy tongue and anorexia

• tachycardia, palpitations, cardiomegaly, heart failure

B12 deficiency lab

•macrocytic anemia

•↑ MCV

•↓ serum B-12

•mild leukopenia and thrombocytopenia

•smear looks just like FA deficiency!!

treatment B12 (cyanobalamin)

•may be given orally, IN, or parenterally (IM/SQ)

•Parenteral –

• most common

• more reliable

• may circumvent the need for a Schilling Test

•IN (Nascobalm)

• may be used after initial parenteral treatment if no CNS involvement.

folate deficiency lab

•smear looks just like B-12  deficiency!!

•macrocytic

•↓ serum folate levels

•S/S similar to Fe def (and B12 if severe)

folate deficiency causes

•ETOH

•pregnancy

•malabsorption/ inadequate intake

•Drugs

• Phenytoin

• MTX

• Colchicine

treatment folate

•Must also check B-12 level to avoid masking B12 deficiency!!

•1 mg/day po

•may need up to 5 mg/day in some cases of malabsorption

•Hgb will ↑ 2 wks after initiation of therapy and may normalize after 2-4 months

•may d/c if underlying deficiency is corrected

drug-induced hemolytic anemia

generally will happen quickly

drug-induced hemolytic anemia common symptoms

•Common symptoms:

• Dyspnea/Fatigue

• dark urine

• pale or jaundiced

• enlarged spleen

• tachycardia/murmurs

•A number of meds have been implicated

drug induced hemolytic anemia treatment

•Removal of offending agent

•Transfusion considered if severe

•Possible use of glucocorticoids or IVIG

drug that can cause folate deficiency

• phenytoin

• methotrexate

• colchicine