Clin Med/ Pathophys & Diagnostic/Lab methods Flashcards
microcytic iron deficiency anemia etiology
caused by bleeding unless proved otherwise. can be: deficient diet, decreased absorption increased requirements, chronic blood loss, hemoglobinuria , iron sequestration, idiopathic
microcytic iron deficiency anemia signs/sxs
those of anemia itself: fatigue, tachycardia, palpitations, SOB on exertion, smooth tongue, brittle/spooning nails, cheilosis.
microcytic iron deficiency anemia dx workup
low MCV (RBC cell size), low reticulocytes, low ferratin values. Bone marrow bx rarely done. Eval labs and pt’s response to therapeutic trial of iron replacement to determine cause.
microcytic iron deficiency anemia tx
oral/parenteral iron
microcytic iron deficiency anemia complications
long term anemia - heart probs, growth probs, probs during pregnancy
microcytic iron deficiency anemia prevention
take supplements/adequate diet
microcytic thalassemia anemia - major/minor etiology
hereditary disorders characterized by reduction in the synthesis of globin chains. this causes reduced hemoglobin synthesis and thus anemia. 2 types: alpha (caused by gene mutations) and beta (caused by point mutations)
microcytic thalassemia anemia - major/minor signs/sxs
Alpha minor: clinically normal, normal life expectancy, performance status and mild microcytic anemia to pallor/splenomegaly.
Alpha major: no hemoglobin produced. stillborn.
beta minor: clinically insignificant.
beta major: stunted growth bony deformities, HSM, jaundice, cirrhosis, thrombophilia.
microcytic thalassemia anemia - major/minor dx workup
hematocrit, genetic counseling, CBCs, retic count, iron, MCV, blood smears
macrocytic folic acid deficiency anemia etiology
alcohol abuse, anorexia, malnutrition, overcooked foods, concurrent B12 deficiency, decreased absorption of iron (from drugs), increased iron requirement, loss of iron (from dialysis)
macrocytic folic acid deficiency anemia signs and sxs
megaloblastic anemia, glossitis, vague GI disturbances (anorexia, diarrhea)
macrocytic folic acid deficiency anemia dx workup
RBC folic acid level <150ng/mL. B12 can be normal, though.
macrocytic folic acid deficiency anemia tx
folic acid supps
macrocytic B12 deficiency anemia etiology
decreased intrinsic factor production, gastrectomy, dietary deficiency, competition for B12 in gut, decreased absorption, pancreatic insufficiency, H pylori infxn.
macrocytic B12 deficiency anemia signs/sxs
similar to folic acid deficiency + some neuro symptoms. Slow onset anemia such that the sxs might go unnoticed. pallor/mild icterus, glossitis, vague GI issues, neurologic manifestations (peripheral neuropathy, difficulty with position or vibration sensation/balance, dementia).
macrocytic B12 deficiency anemia dx workup
low serum B12 <100.
macrocytic B12 deficiency anemia tx
IM or SubQ inj of B12, PO/sublingual replacements. folic acid replacement, RBC transfusions if severe + diuretics.
macrocytic B12 deficiency anemia complications
altered cerebral fxn, dementia, hypokalemia.
normocytic anemia of chronic disease etiology
associated w chronic diseases: cancer, collagen vascular disease, chronic infections, DM, CAD. caused by low RBC production d/t trapped iron stores in macrophages or reduced uptake in the gut, decreased EPO production, impaired bone marrow response to EPO.
normocytic anemia of chronic disease signs/sxs
mild generalized fatigue, dizziness, mild palpitations, sometimes pallor of palpebral conjunctivae
normocytic anemia of chronic disease dx workup
often diagnosed incidentally by labs: slight Hb decrease (10-11 g/dL), hypo chromic RBCs, MCV normal to low, low absolute retic count, elevated acute phase reactants (ESR, platelets, fibrinogen), reduced transferrin, increased ferritin, low serum iron and total iron binding capacity w normal % saturation
intrinsic defects leading to hemolytic anemias
membrane (hereditary spherocytosis, paroxysmal nocturnal hemoglobulinuria), enzyme systems, hemoglobin (sickle cell, thalassemia)
extrinsic causes leading to hemolytic anemias
immune (autoimmune, lymphoproliferative disease, drug tox), microangiopathic hemolytic anemia (vasculitis), infection of RBCs (malaria, clostridium, lyme dz), hypersplenism, burns.
sickle cell anemia etiology
homozygous mutation in beta Hb chain. Hb molecules w 2 normal and 2 abnormal chains. elongated fibers: sickle cell shaped RBC
sickle cell anemia pathophys
abnormally shaped RBCs occlude capillary beds. sickled cells are prone to hemolysis which leads to a free Hb which attaches a nitric toxic and causes endothelial dysfxn, vascular injury, and pulmonary HTN.
sickle cell anemia epidemiology
genetic: autosomal recessive inheritance; African, Mediterranean, or S Asian heritage; confers resistance to malaria; 30% present symptoms by 1 year, 90% by age 6
sickle cell anemia signs/sxs
acute pain episodes in extremities, abdomen, back, chest. fever, joint swelling, vomitting, tachypnea
sickle cell anemia lab findings
retic count: increased. Hb mild to mod decrease. elevated bilirubin and lactate dehydrogenase. on blood smear: sickling RBCs, Howell-Jolly bodies, target cells. WBC: elevated 12-15K
sickle cell anemia mgmt
hospitalization during attack: hydration and oxygenation, analgesia, antibiotics if infection present. blood transfusions.
sickle cell anemia complications
recurrent acute vasculocclusive crisis. in pregnancy: HTN, infections, preterm birth, fetal growth restrictions, increased maternal mortality.
paroxysmal nocturnal hemaglobulinuria etiology
acquired clonal hematopoietic stem cell disorder. abnormal sensitivity of RBC membranes to lysis by complement. may progress to aplastic anemia, myelodysplasia, or acute leukemia.
paroxysmal nocturnal hemaglobulinuria pathophys
free Hb released into blood scavenges nitric oxide. esophageal spasms, erectile dysfxn, renal damage, thrombocytosis, drop in pH while sleeping facilitates hemolysis.
paroxysmal nocturnal hemaglobulinuria epidemiology
this is genetic.
paroxysmal nocturnal hemaglobulinuria lab findings
mild to very severe anemia (+/- reticulocytosis). hemosiderin due to hemolysis. serum LD: elevated. iron deficiency normo-macrocytic RBCs.
paroxysmal nocturnal hemaglobulinuria mgmt
mild dz: no tx.
severe: RBC transfusions and eculizumab (compliment antibiody), folic acid supps
paroxysmal nocturnal hemaglobulinuria complications
death due to thrombosis
sickle cell trait etiology
heterozygous “carrier” for B-Hb chain mutation
sickle cell trait signs/sxs
if only carrier, most likely none.
sickle cell trait mgmt
no tx necessary. genetic counseling.
sickle cell trait complications
sudden cardiac death, rhabdo during vigorous exercise (esp at altitude), possible increased risk for venothromboembolism, possible increased risk for chronic kidney dz
hereditary spherocytosis etiology
hereditary form of intrinsic hemolytic anemia (i.e. defect involves RBC itself). most commonly an autosomal dominant disorder
hereditary spherocytosis pathophys
microspherocytic shape of RBCs conferred by abnormalities in the cytoskeleton of the cell membrane, decreased pliability leads to increased hemolysis when passing through small capillaries of the spleen.
hereditary spherocytosis signs/sxs
neonatal jaundice, anemia, jaundice, splenomegaly, cholecystitis/cholelithiasis
hereditary spherocytosis lab findings
the peripheral blood smear shows spherocytes w a normal to low MCV and increased MCHC (>36%). diagnosis is established by the osmotic fragility test.
hereditary spherocytosis mgmt
folate therapy and splenectomy may be necessary in severe cases
G6PD deficiency etiology
glucose-6-phosphate dehydrogenase deficiency (enzyme). hereditary enzyme defect causing episodic hemolytic anemia.
G6PD deficiency pathophys
the antioxidant glutathione is unable to be reduced by the defective enzyme G6PD. increased concentration of oxidized glutathione causes denaturing Hb which precipitates out of solution to form Heinz bodies which damage cell membrane of RBC. Damaged membranes lead to premature RBC removal by spleen (extravascular hemolysis)
G6PD deficiency epidemiology
X linked genetic disorder. M>F.
G6PD deficiency signs/sxs
pts usually healthy w/out hemolytic anemia or splenomegaly. hemolysis occurs episodically in response to infection and certain drugs.
G6PD deficiency lab findings
normal labs between episodes. peripheral blood smear may show “bite” cells (look like they’ve had a bite taken out of them) or “blister” cells. Heinz bodies may be visible with stain. G6PD may be measured with specific enzyme assays.
G6PD deficiency mgmt
no tx necessary except to avoid drugs known to trigger acute episodes.
autoimmune hemolytic anemia etiology
acquired hemolytic anemia caused by IgG autoantibody
autoimmune hemolytic anemia pathophys
IgG binds RBC membrane leading to macrophage phagocytosis.
autoimmune hemolytic anemia epidemiology
1/2 of all cases are idiopathic. may be seen in association with SLE.
autoimmune hemolytic anemia signs/sxs
rapid onset of anemia that may be life threatening. fatigue. dyspnea. angina.
autoimmune hemolytic anemia lab findings
Coombs test (agglutination is + indicating presence of IgG)
autoimmune hemolytic anemia mgmt
prednisone is initial tx (PO 1-2mg/kg/d). transfused blood may be subject to hemolysis as well, should consult hematology and blood bank specialists. splenectomy may cure the disorder.
hemochromatosis etiology
an inherited disorder of iron metabolism in which iron absorbed through the intestine results in excess amounts of iron with eventual tissue damage and impaired function in many organs. (Iron overload)
hemochromatosis signs/sxs
most pts are asymptomatic. rarely recognized clinically before the 5th decade of life. early sxs are fatigue, arthralgia. late manifestations are arthropathies, hepatomegaly, hepatic dysfunction, cardiac enlargement, bleeding from esophageal varices, and impotence in men.