General Surgery Rotation

General Surgery: Anemia

General Surgery Rotation

Microcytic Anemia - Anemia of chronic disease, iron deficiency anemia

Iron deficiency anemia
Etiology	Signs and Symptoms	Laboratories	Treatment
Most common anemia in the US Always consider GI bleed Associated with pica and nail spooning	Anemia: weakness, fatigue, bruising/gum bleeding, sore tongue (unique) Neuropsychiatric manifestations: peripheral neuropathy, balance probs, depression, dementia → can be irreversible if untreated Glossitis: beefy red tongue Signs: Loss of vibratory and fine touch	Decreased serum iron, ferritin, and transferrin saturation Microcytic (MCV < 80) and hypochromic (↓ MCH and MCHC) anemia with low H/H Low Ferritin < 15 mg/ml (best test), high TIBC Target cells	Oral iron: Ferrous sulfate (eg, as 325 mg of ferrous sulfate QD or BID) - Give between meals with juice (not milk) Ferrous fumarate - 100-200 mg/day in 2-3 doses Ferrous gluconate - 3-6 mg/kg/day in 3 doses 6 wk to correct anemia 6 mo to replete iron stores Recheck blood counts every 3 mo × 1 y Vitamin C—helps to absorb iron Increasing reticulocyte count is an indication that iron is working
Lead poisoning is a common question on the PANCE/PANRE look for basophilic stippling and remember treatment is with EDTA.
Anemia of chronic disease
Anemia of chronic disease is a multifactorial anemia often coexistent with iron deficiency.	Diagnosis generally requires the presence of chronic infection, inflammation, or cancer; microcytic or normocytic anemia; and values for serum transferrin receptor and serum ferritin that are between those typical for iron deficiency and sideroblastic anemia.	Low EPO Iron studies Decreased serum iron and TIBC, transferrin saturation NL to 3× increase serum ferritin Peripheral smear: normocytic, normochromic (cancer, CKD) to microcytic hypochromic (TB, RA) ↓ serum erythropoietin levels in anemia of renal failure ESR: increased	Erythropoietin 50-150 U/kg IV 3 × weekly Treat the underlying disease

Vitamin B12 and Folic acid Deficiency Anemia (Macrocytic Anemia)

CBC: MCV > 100 Inhibition of DNA synthesis during RBC production Iron Studies Normal to increased: serum iron, ferritin, and transferrin saturation Normal to decreased: TIBC Peripheral smear: macrocytic, megaloblastic
Vitamin B12 deficiency
Etiology	Signs and Symptoms	Laboratories	Treatment
Autoimmune destruction of gastric parietal cells → atrophic gastritis → lack of intrinsic factor production (required for absorption in small intestines) Cofactor for 2 enzymatic reactions required for DNA synthesis, brain/nervous system function, formation of RBC Causes/RF: Chronic alcoholism, vegetarian, celiac and Crohn diseases, gastric bypass surgery, Parasites MCC: Pernicious anemia (lack of IF)	Anemia: weakness, fatigue, bruising/gum bleeding, sore tongue (unique) Neuropsychiatric manifestations: peripheral neuropathy, balance probs, depression, dementia → can be irreversible if untreated Glossitis: beefy red tongue Signs: Loss of vibratory and fine touch	B12 level: decreased, can be false (+) with folate deficiency Homocysteine: increased Methylmalonic acid (MMA): increased Hypersegmented neutrophils	Lifelong IM B12: 1-3 ug/d (animal products, fortified cereal) for pernicious anemia IV Cyanocobalamin 1 mg IM daily × 7 d, then weekly × 4 wk, then monthly for life PO B12 1-2 mg PO daily for vegans and bariatric surgery Years to deplete stores
Folate deficiency
Etiology	Signs and Symptoms	Laboratories	Treatment
Cofactor for DNA synthesis Alcoholics and malnourished have smaller stores Decreased intake, increased requirement (pregnant), sickle cell anemia, thalassemia Sprue, Crohn, drugs	looks like B12 but no neurologic symptoms Neural tube defects (spina bifida)	Homocysteine: increased Serum folic acid: low RBC folic acid (more reliable show of stores): <150 (diagnostic) Macro-ovalocytes and hypersegmented PMNs (pathognomonic)	PO folic acid 1-5 mg/d (first line) Avoid ETOH and folic acid antagonists (Bactrim, phenytoin, sulfasalazine) Green leafy vegetables, yeast, legumes, fruits, animal proteins Prophylactic folic acid— pregnant/lactating women, contemplating pregnancy, sickle cell patient

Hemolytic Anemias:
Glucose-6-Phosphate Dehydrogenase Deficiency, Hereditary Spherocytosis, Sickle Cell Anemia, Thalassemia
CBC: Reticulocyte count: ↑ high (Hallmark) Symptoms of acute and chronic anemia dark urine back pain jaundice Iron studies Increased: serum iron, ferritin, and transferrin saturation Decreased TIBC Check hemoglobin and hematocrit Check at 12 and 18 mo, 12 y (females) Hb/Hct <2× standard deviation of normal Hb < 13.5 g/dL or → Hct <39% (men) Hb <12 g/dL or Hct <37% (women) Total (indirect) bilirubin increased, Haptoglobin decreased Peripheral smear: microcytic, normochromic anemia, spherocytes Bone marrow biopsy
G6PD deficiency
Etiology	Symptoms	Laboratories	Treatment
After infection or medication (oxidative stress) → Depletion of reduced glutathione = oxidation of Hgb = precipitation of Hgb → Heinz bodies) + Bite cells → RBC destruction Most commonly seen in tropical geographic areas prevalent for malaria (Africa, China, and Mediterranean regions) Flare triggers: Fava beans, antimalarials, sulfonamides	Mild jaundice Mild-moderate anemia Malaise, abdominal discomfort in LUQ Signs: Splenomegaly	Peripheral smear: Bite cells, Heinz bodies	Avoid potentially harmful drugs, monitor infection Acute—blood transfusion
Hereditary Spherocytosis
Etiology	Symptoms	Laboratories	Treatment
Inherited dysfunction or deficiency in one of the erythrocyte membrane proteins (spectrin, ankyrin, band 3 protein, or protein 4.2) → spherocytic erythrocytes are sequestered and destroyed in the spleen Autosomal dominant	Mild jaundice Mild-moderate anemia Malaise, abdominal discomfort in LUQ Signs: Splenomegaly	CBC: anemia MCV: decreased Reticulocyte count, LDH, indirect bilirubin, stool urobilinogen: elevated Wright-stained smear: spherocytes Hgb: 4-6 g/dL (low) EDW: elevated Peripheral smear: spherocytes Osmotic fragility: increased Coombs test: negative	Splenectomy Indicated even when anemia compensated and asymptomatic Delay operation until children are age 6 Cholecystectomy if gallstones present Complications: Hypoplastic crises: follow acute viral illness → profound anemia, headache, nausea, pancytopenia, hypoactive marrow, pigmented gallstones
Sickle Cell Anemia
Etiology	Symptoms	Laboratories	Treatment
Mutation in the β-globin gene that changes the sixth amino acid from glutamic acid to valine	Acute pain Few hours to 2 wks RF: infection, fever, excess exercise, anxiety, an abrupt change in temperature, hypoxia, hypertonic dyes Signs: Tenderness, fever, tachycardia, anxiety Complications: Pulmonary hypertension, ESRD, hand-foot syndrome, priapism → permanent impotence	Very ↑ Retic count + Pain in African American male Hemoglobin electrophoresis: Hemoglobin S Blood smear: Sickled RBCs, Howell-Jolly bodies, target cells)	Crisis: Vigorous hydration Aggressive pain medication (morphine) Nasal O2 Severe symptoms: Hydroxyurea (mainstay), for patients 3+ crises per year or repeated ACS - Increases production of Hgb F (cannot sickle) BMT Health maintenance: Regular slit lamp exams: retinopathy Antibiotics for splenectomy patients undergoing dental or invasive procedures Vigorous oral rehydration during or in anticipation of periods of extreme exercise, exposure to heat/cold, emotional stress, or infection Pneumococcal and Hib vaccines early in life
Autoimmune Hemolytic Anemia
Etiology	Symptoms	Laboratories	Treatment
Autoantibodies bind to the patient's own erythrocytes, leading to premature red cell destruction (hemolysis) Warm and cold types Warm (90%) - immunoglobulin (Ig)G, that bind preferentially to the red cells at 37°C, Cold (10%) < 37° C	anemia pallor, dyspnea acrocyanosis and livedo reticularis Mild splenomegaly is typical	+ Direct Coombs Test ↑ Retic ↑ LDH ↓ Haptoglobin ↑ Bilirubin (indirect)	Dependent on disease severity Rituximab Glucocorticoids, cyclophosphamide, cyclosporine, IVIg
Thalassemia
Etiology	Signs and Symptoms	Laboratories	Treatment
β-thalassemia Only 2 β-globin genes on chromosome 11, but 4 α-globin genes on chromosome 16 Disrupts ratio between α and β chains, changing the stability of Hb → hemolysis	Asymptomatic Mild anemia Signs: Hepatosplenomegaly Jaundice	Hgb electrophoresis CBC: microcytic hypochromic anemia Iron studies NL to increased: serum iron, ferritin, and transferrin saturation Normal TIBC Peripheral smear: target cells, basophilic stippling, elliptocytes	Symptomatic Cardiovascular instability, continued/excessive blood loss—transfuse Asymptomatic: PO iron repletion (200 mg per day) and B12 - only if concomitant iron deficiency anemia An allogeneic bone marrow transplant Folic acid 5 mg daily Deferoxamine (iron chelator) Splenectomy for splenomegaly Poor prognostic factors: Chronic infection, liver or heart failure, die in 20-30 s

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