hematology Flashcards
anemia
reduction in circulating RBCs. d/t decrease in production, abnormalities of the cells, shortened life span, destruction, or loss from bleeding. causes of microcytic (low MCV) hypochromic (low MCH) is iron deficiency, lead poisoning, thalassemia. causes of macrocytic: exposure to certain meds, low B12 or folate, liver disease, hypothyroidism. hypo proliferative anemia is from failure in RBC production and is normocytic, normochromic. hemolytic affects retic count. initial dx: CBC, retic, peripheral blood smear; can do ferritin, Fe, TIBC.
microcytic anemia: iron deficiency
most common nutritional disorder. risks: childhood obesity, rapid growth, heavy menses, inadequate diets, hx of preemie or low birth weight, overuse of goat’s/cows milk or prolonged bottle feeding. malabsorption (celiac, Crohn, giardiasis). rapid transit (colitis, blood loss, NSAIDS). first do Hgb can do ferritin and CBC; universal screening at 1 year. then risk assessments. early deficiencies affect cognitive abilities into adulthood. lead poisoning is often a comorbidity. screening done at 15 and 30 months too. if >5, concern. s/s: irritable, restless, pica, anorexia, DD. venous sampling most reliable. tx: trial iron 4-6weeks and then followup labs in 1mo with hub improving 1-2 and retic. >3% in 2-3 days. if initial Hgb <4 consult h/o; if <7 assess need for referral. microcytic/hypochromic RBCs, low or normal MCV, high RDW, low ferritin, high TIBC, mentzer index >13. preemies need supplement weeks 2 to 1 year. breastfed only need 1mg/kg/day supplement starting at 4mo. no cow’s milk <1 year. avoid iron with meals/milk, vC enhances it, stool turns black.
iron doses for IDA
ferrous sulfate 3-6mg/kg/day in 3 divided doses. assess retic. in 1 week; if therapeutic response, continue until normal Hgb and then for 2-3 months to restore iron stores.
anemia red flags
abnormal vitals, neutropenia/thrombocytopenia, high MCV with normal RDW, blasts on peripheral smear, firm adenopathy, bruising/bleeding, weight loss, failure to thrive, SOB, fever, hypoxia, organomegaly, edema, oliguria, bloody diarrhea, red urine, family history.
thalassemia
alpha and beta. minor is hetero, major is homo and more severe. B thalassemia major, severe anemia and needing ongoing transfusions; possibility increases if onset is <3-6momths and family history. heterozygous disease is hypochromic and microcytic; homozygous is also hemolytic. increased erythropoiesis. focal osteomalacia and delayed bone maturation.
A thalassemia
homozygous results in hydros fetalis and is incompatible with life. can also be microcytic hypochromic and hemolytic anemia. 2 different carrier states with microcytosis/hypochromia but normal Hgb. Hgb H needs transfusions during hemolytic or aplastic crises. no tx for carrier state except genetic counseling.
B thalassemia
minor is trait. Hgb 2-3 below normal and MCV averages 65. monitor for iron accumulation but otherwise asymptomatic. diagnostic feature is Hgb A2 >3.5% on electrophoresis. Mentzer <13 thalassemia, >13 d/t iron. most asymptomatic but may have mild pallor and splenomegaly. thalassemia intermedia management is keeping Hgb 6-7+. Major: Cooley anemia. severe anemia and hemolysis. pallor, FTT, hepatosplenomegaly, severe anemia Hgb 6 and low mCV 60-70. microcytosis, poikilocytosis, hypochromia, target cells, nucleated RBCs. type erythrocyte profile prior to first transfusion. stem cell transplant only cure. may need iron chelation d/t frequent transfusions. (deferasirox). if untreated, facies, frontal bossing and maxillary overgrowth. `
platelet disorders
r/o prior to extensive surgery and in kids with petechiae, frequent nosebleeds, mucus membrane bleeding, or excessive bleeding. initial labs: CBC, platelet, PT, aPTT. typical lab findings of hemophilia are normal PT and PFA and abnormal aPTT. if both PT/aPTT are elevated with thrombocytopenia > DIC.
Idiopathic thrombocytopenia purpura
autoimmune response where platelets are destroyed, often after a viral illness. mostly 1-4 years old, usually resolve within 6 months without treatment. if >1 year, chronic ITP and needs careful workup for diffs: leukemia, med reaction, SLE, cirrhosis, HIV, hepC, congenital causes, etc. s/s usually when platelets <20,ooo: petechiae, purpura, bleeding, recent viral illness within a month, hemorrhage, nosebleeds, menorrhagia, enlarged lymph nodes, bone pain/pallor, low platelets, normal coat factors and WBC/RBC. r/o HUS if fragmented RBCs. in sick, febrile child consider meningitis. tx: if platelet >20,000 and no bleeding: avoid sports, aspirin and NSAIDS and herbal stuff that interferes. in severe cases, steroids and can do IVIG.
Hemophila A (VIII) and B (IX)
severity determined by percentage of function of factor level with 100%. less than 1% severe, 1-5 moderate, >5 mild. von Willebrand heterogeneous hereditary bleeding disorders d/t abnormality of vWF protein. in type I its quantitatively reduced, in type II its qualitatively abnormal, in type III its absent. sex-linked recessive so hemophilia A/B affect primarily males. A is 4x more common. s/s hemophilia: family hx, excessive bruising, prolonged bleeding, hemarthrosis, greatly prolonged aPTT, assay for factors confirms. s/s von Willebrand: mucous membrane bleeding, history of ecchymosis, factor VIII clotting decreased, vWF antigen usually decreased.
hemophilia management
replacement therapy. application of cold and pressure to joints that have blood. avoid NSAIDs. avoid high risk sports. immunizations with 26 gauge subQ or 23 gauge IM with firm pressure and ice at site several minutes. tx for von Willebrand disease is DDAVP and factor VIII-vWF. aminocaproic acid sometimes used for dental extraction or nosebleeds.
hemophilia management
replacement therapy. application of cold and pressure to joints that have blood. avoid NSAIDs. avoid high risk sports. immunizations with 26 gauge subQ or 23 gauge IM with firm pressure and ice at site several minutes. tx for von Willebrand disease is DDAVP and factor VIII-vWF. aminocaproic acid sometimes used for dental extraction or nosebleeds. thrombophilia
thrombophilia
increased ability to form blood clots; acquired or inherited. most common inherited are factor V Leiden, prothrombin 20210 mutation, antithrombin, protein C/S deficiency. 2+ traits shown to be at increased risk for VTE. most common risk factor: CVL, surgery, trauma, OCs, immobilization, infection, SLE, structural venous anomalies and cancer.
Pancytopenia
decrease in all elements of the blood. d/t production failure, sequestration, increased peripheral destruction. refer to h/o. will likely need stem cell transplantation.
WBC
leukocytosis increase in number of circulating leukocytes. increase in number of circulating immature neutrophils (bands) left shift, is response to inflammation or infection. low ANC to less than 1500 for those >1 year or <1000 for infants. moderate is 500-1000, severe is ANC <500. d/t infections, drugs, peripheral destruction, pooling, hemodialysis, cardiopulmonary bypass. most common infectious causes hep A and B, RSV, influenza A and B, EBV, CMV. neutrophil in newborns is 20-30% adult pool so easily depleted with stress leading to sepsis.
