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Blood Bank Exam 4
HDFN, AIHA, Transfusion Reactions, Therapy in select pts
| Question | Answer |
|---|---|
| Define Hemolytic Disease of the Fetus and Newborn (HDFN) | Destruction of red blood cells of a fetus or neonate by maternal antibodies |
| List the criteria for HDFN to occur | Mother was exposed to foreign antigen, exposure resulted in immunization, antibody is able to cross placenta, fetus must have the antigen mom has antibody to. |
| Discuss anemia and bilirubin in relationship to HDFN in utero. | Anemia is a problem in utero since the fetal RBCs are destroyed resulting in extramedullary hematopoiesis. When severe this causes enlarged spleens and liver and immature red blood cells. The mother processes the bilirubin of the fetus in her liver. |
| Discuss anemia and bilirubin in relationship to HDFN in neonates | After birth, the newborn liver is unable to conjugate bilirubin for a while. The increased bilirubin exceeds the binding capacity of albumin and the level can become toxic. |
| differentiate between direct and indirect bilirubin. | Indirect bilirubin is unconjugated and processed by the liver to become conjugated (or direct) bilirubin which is then excreted from the body. |
| Erythroblastosis fetalis | Destruction of fetal RBCs stimulate fetal bone marrow to accelerate the production of red cells |
| hydrops fetalis | erythropoiesis in the fetal liver is so extensive that the portal circulation is disrupted, albumin synthesis is impaired, plasma colloid osmotic pressure is reduced, and the heart pumps harder to increase oxygenation |
| extraamedullary hematopoiesis | red blood cell formation outside of the bone marrow. |
| Kernicterus | "nuclear jaundice" due to excess bilirubin crossing the blood-brain barrier and accumulating in the CNS. Unconjugated bilirubin in the nuclei of the brain and nerve cells cause destruction and encephalopathy |
| Hemolysis | Blood cell destruction. |
| Zygosity | the degree of similarity of the alleles for a trait |
| Phototherapy | infant is placed under UV light which breaks down bilirubin into non-toxic products which can be excreted by the liver. |
| Wharton's Jelly | gelatinous substance found in cord blood. |
| Blocked D (Rh) | D antigens become blocked in HDFN by maternal IgG anti-D antibodies which prevents IgM reagents from binding the |
| Petechiae | small round red or purple spots on the skin due to bleeding under the skin. |
| Ecchymoses | subcutaneous bleeding larger than 1 cm. |
| what 5 factors influence HDFN? | Antigenic exposure, host factors, immunoglobulin class, antibody specificity, maternal ABO group. |
| Prenatal testing | usually done at first prenatal visit in the first trimester. Weak D testing is required and paternal zygosity should be considered. ABID should be done to determine if antibody is significant. Antibody titers to monitor antibodies, should be <32 |
| postnatal testing | For the infant consists of ABRh typing; Direct Coombs; CBCD to determine HH, NRBC, and spherocytes; bilirubin; |
| What maternal antibodies are always significant to HDFN? | anti-D, -D&C, -D&E, -C, -E, -c, -e, -K are all significant to HDFN. |
| What maternal antibodies almost never (rarely) cause HDFN? | anti-Fya, -s, -M, -N, -S, -Jka are rarely significant to HDFN. |
| What maternal antibodies never cause HDFN? | anti-Lea, -Leb, -I, -IH, -P1 are never causes of HDFN. |
| What is the Liley system of measuring bilirubin? | uses optic density to measure 3 zones of bilirubin (1) lowest indicates mild-no disease, no intervention needed (2) moderate disease suggests intrauterine xfusion/delivery may be needed (3) severe/life threatening intrauterine xfusion/delivery required |
| What is the Queenan system for measuring bilirubin? | uses optic density to measure 4 zones of bilirubin which include: Rh neg (unaffected), indeterminate, Rh pos (affected), and intrauterine death risk. |
| Describe the procedure for PUBS | uses high-res ultrasonography w/ color doppler enhancement of blood flow to insert a needle into the umbilical cord. Gives HH, ABRh, antigen typing, and DAT data. |
| Describe the procedure for amniocentesis | surgical puncture of amnion sac to remove amniotic fluid for testing performed by transabdominal insertion of needle through abdomen using ultrasound guidance. Can be used for genetic testing or monitoring bilirubin in fluid. |
| Describe the procedure for chorionic villus testing | Removal of placental tissue which shares baby's genetic make-up. done at 10-13 weeks and fetal antigens can be determined. Uses PCR methodology. |
| Describe the procedure for IUT | In utero transfusions include intraperitoneal and intrauterine transfusions to treat fetal anemia evidenced by amniotic fluid optical density test in zone 2-3, cordocentesis hgb <10 mg/dL, or fetal hydrops noted on ultrasound. |
| Describe the procedure for MCA | Color Doppler, a noninvasive procedure that uses doppler to evaluate fetal middle cerebral artery peak blood flow velocity and correlates with severity of anemia. |
| what is an intraperitoneal transfusion? | radio opaque dye introduced into amniotic fluid which baby swallows to highlight stomach and intestines. Needle inserted through mom's abdomen into intraperitoneal cavity of fetus and slowly infuse 40-100 mL of blood which is absorbed by lymphatic system |
| describe an intrauterine transfusion | Inserted directly through umbilical vein usually after 20 weeks of gestation. |
| What are the categories of HDFN? | ABO system, Other Systems, Rh System |
| What is the purpose of intrauterine transfusion? | to maintain hgb of 10 mg/dL |
| What is the purpose of exchange transfusion? | provide viable red cells for oxygen delivery, remove maternal circulating antibody, remove circulating bilirubin, and remove sensitized red cells. |
| What is the composition of RhIG? | Prepared by pooling human plasma from individuals sensitized to the D antigen. Plasma is subjected to cold alcohol fractionation and purified so that it contains almost exclusively IgG. it is also virus inactivated. |
| What is the mechanism of RhIG? | anti-D in RhIG masks the antigen on fetal Rh pos cells in maternal circulation and prevents recognition of them by mom's immune system. May facilitate clearance of antibody coated Rh pos cells before they can elicit immune response. |
| When is RhIG used? | usually given prophylactically at 28 wks to Rh neg moms since 98% of women who are going to develop anti-D will do so after 28 wks. Also given w/in 72 hours postpartum. |
| How much RhIG is to be given? | One dose is 300 micrograms which is good for 15 mL packed cells or 30 mL whole blood. |
| What is the Fetal Cell Screen? | Rh positive fetal cells coated w/ anti-D form rosettes w/ addition of Rh pos indicator cells, based on detection of Rh pos cells in Rh neg mother |
| What is the Kleihauer-Betke test? | Acid elution test used since fetal hgb is resistant to acid elution and stains red w/ eosin dyes. adult hgb is eluted w/ acid and red cells appear as colorless ghost cells |
| What criteria must be met for intrauterine transfusions? | Requires that the blood is less than 7 days old, CMV negative, Hgb S negative, negative for antigen mom has antibody to, compatible w/ infant's ABRh, and irradiated. |
| what criteria must be met for exchange transfusion? | Requires that the blood is less than 7 days old, CMV negative, Hgb S negative, negative for antigen mom has antibody to, compatible w/ infant's ABRh, and irradiated. |
| What 2 types of HDFN occur because of maternal immune thrombocytopenia? | Fetal/Neonatal Allo-immune thrombocytopenia (FNAIT) and Immune Thrombocytopenia Purpura (ITP) |
| What is FNAIT? | caused by maternal antibodies specific for platelet antigens inherited from the father. |
| What is ITP | Autoantibody in mom that reacts w/ the infant's platelets. |
| symptoms of kernicterus | lethargy, poor feeding, respiratory distress, rolling of eyes, high pitched cry, extending of body, bloody froth from nose, mental retardation, and death |
| How much whole blood will one dose of RhIG treat? | 30 mL |
| How much packed red cells will one dose of RhIG treat? | 15 mL |
| Antigenic exposure | caused by fetal maternal hemorrhage (FMH) which occurs in around 7% of women during pregnancy. Can occur due to trauma in the abdomen which can sometimes include delivery. |
| Host factors | The mother's ability to produce antibodies depend on genetic factors. Only around 9% of Rh Neg mothers will develop antibody if not treated w/ RhIG |
| Immunoglobulin class | IgG is the only one that can cross placenta and as early as 2nd trimester. IgG is on the Fc portion of the antibody and IgG1 and -3 cause more hemolysis than -2 and -4. |
| antibody specificity | D; C,E,c; Kell; and ABO |
| Influence of mom's ABO group | If HDN due to both the ABO and Rh, may have a protective effect for the baby. Naturally occurring ABO antibodies destroy red cells before the mother can produce Rh antibody |
| How is the amount of transfusion for intrauterine transfusion determined? | (gestational age - 20) x 10 = mL to transfuse |
| HDFN Category ABO system | most common and usually seen in group O moms. Normally mild with weak positive DC, slow rising bilirubin, and spheres retics and NRBCs on smear. Treated w/ phototherapy |
| HDFN Category other systems | Occur due to Kell, Cc, Ee, Kidd, Duffy, MNSs. Most from previous transfusion and cause mild HDFN. |
| HDFN Category Rh system | Occurs due to D antigen and most severe HDFN. Usually doesn't occur in 1st born and is not very common. |
| Formula to determine RhIG dosage in whole blood | # of fetal cells/2000 x 100 = % of fetal cells. % fetal cells x 50 = mL bleed. mL bleed/30 = # of vials to be given |
| formula to determine RhIG dosage in packed red cells | # of fetal cells/2000 x 100 = % of fetal cells. % fetal cells x 50 = mL bleed. mL bleed/15 = # of vials to be given |
| S/S of Acute Hemolytic Transfusion Reaction | fever, chills, flushing, pain at infusion site, tachycardia, tachypnea, lower back pain, hgbemia, hgburia, hypotension, severe w/ rapid onset, usually intravascular |
| Causes of Acute hemolytic Transfusion Reactions? | Usually ABO incompatibility, ag/ab reaction causes rapid activation of complement. Usually caused by human error in pt and spec ID. Takes <5 mLs |
| What is the treatment for Acute hemolytic Transfusion Reactions? | treat the hypotension and DIC, maintain adequate blood flow. |
| What lab results are related to Acute hemolytic Transfusion Reactions? | increased plasma free hgb, serum bilirubin, decreased haptoglobin, hgburia, DAT can be pos/neg |
| S/S of Delayed Hemolytic Transfusion Reaction | Occurs 3-10 days post transfusion. Fever w/ or w/o chills, may have decreased HH w/ no explanation, mild jaundice, usually extravascular. |
| Causes of Delayed Hemolytic Transfusion Reaction? | alloantibody w/ low concentration anamnestic response on reexposure, usually the Kidd blood group, Rh (e,E,C), fy, K, or Jka. |
| what is the treatment for Delayed Hemolytic Transfusion Reaction? | normally not necessary but may use steroids. |
| What lab results are related to Delayed Hemolytic Transfusion Reaction? | DAT positive, posttransfusion ABS positive, decreased HH, increased bilirubin and LDH. Elution to ID the antibody in the eluate of post transfusion sample. |
| What causes pseudohemolytic reactions? | exposure of RBCs to extreme temps (burn patients), improper deglycerolization of frozen red cells, mechanical lysis, incompatible solutions, bacterial contam, donors w/ intrinsic abnormal cells |
| S/S of Febrile Non-Hemolytic Transfusion Reaction | fever of at least 1C. May/may not have chills, nausea, vomiting, headache, back pain. |
| Cause of Febrile Non-Hemolytic Transfusion Reaction? | pt HLA antibodies to donor antigens, reaction to cytokines released by WBCs on storage, abs to WBCs plts |
| What is the treatment for Febrile Non-Hemolytic Transfusion Reaction? | antipyretics, acetominophen, give leuko-reduced products in the future |
| What lab results are related to Febrile Non-Hemolytic Transfusion Reaction? | Neg DAT and no visible hemolysis. |
| S/S of Allergic Transfusion Reactions | hives, erythema, itching |
| Causes of Allergic Transfusion Reactions? | pt antibodies to foreign plasma proteins or drugs/food consumed by the donor. |
| What is the treatment for Allergic Transfusion Reactions? | can pretreat w/ antihistamines. May have to give washed RBCs if severe enough reaction. |
| What lab results are related to Allergic Transfusion Reactions? | Neg DAT, no hemolysis |
| S/S of Anaphylactic Allergic Transfusion Reactions? | rapid onset and severe, wheezing, coughing, dyspnea, bronchospasm, respiratory distress, vascular instability, no fever, itching |
| What is the treatment for Anaphylactic Allergic Transfusion Reactions? | Stop transfusion, give epinephrine, give oxygen, keep airways open. In the future transfuse only IgA deficient products. |
| S/S of Transfusion Related Acute Lung Injury | Marked respiratory distress, fever, hypotension, chills, cyanosis, non productive cough, rapid onset |
| Cause of Transfusion Related Acute Lung Injury? | not certain - interation between granulocytes and HLA specific donor antibodies w/ complement activation and promotion of granulocyte aggregation that leads to blockage of lung microvasculature |
| What is the treatment for Transfusion Related Acute Lung Injury? | respiratory support and steroids |
| What lab results are related to Transfusion Related Acute Lung Injury? | neg DAT, no visible hemolysis |
| S/S of Transfusion associated GVHD | 3-30 days post transfusion, fever, erythematous maculopapular rash, abnormal liver function, nausea, vomitin, jaundice, abdominal pain, diarrhea |
| Cause of Transfusion associated GVHD? | transfused immunocompetent T-lymphs attack the recipient |
| Treatment for Transfusion associated GVHD? | unresponsive to medical intervention, so give irradiated products or HLA matched products only |
| S/S of Bacterial Contamination in Transfused products? | same as AHTR, shock is experienced very quickly |
| Causes of Bacterial Contamination in Transfused products? | cold storage viable bacteria like P fluorescens, P putida, Y enterocolitica, E freundii, E cloascae, S epidermidis, and B cereus |
| What is the treatment for Bacterial Contamination in Transfused products? | broad-spec antibiotics and check for contamination before products leave BB |
| S/S of Transfusion Associated Circulatory Overload | dyspnea, severe headache, peripheral edema, signs of CHF |
| What is the treatment for Transfusion Associated Circulatory Overload? | oxygen therapy, diuretic meds, give blood slowly or in aliquots, a unit of packed cells usually given over 2-4 hrs |
| S/S of Post Transfusion Purpura | pt's plt count drops drastically a wk after xfusion, generalized purpura, increased bleeding episodes |
| Causes of Post Transfusion Purpura? | anamnestic response to previous platelet sensitization, usually P1A1 platelet antigen |
| What is the treatment of Post Transfusion Purpura? | plasmapheresis, exchange transfusion, IVIG |
| What diseases can be transmitted through transfusion? | Hepatitis, HIV, HTLV, CMV, EBV, human parvovirus B19, syphillis, malaria, Chagas' disease, babesiosis, leishmaniasis, mad cow (creutzfeldt-Jakob disease |
| Which forms of AIHA are related to IgG? | Paroxysmal Cold Hemoglobinemia and Drug-related autoantibody |
| Which AIHA always involve complement activity? | Cold Reactive autoantibody and paroxysmal cold hemoglobinemia |
| Which AIHA are related to IgM? | Cold reactive autoantibody |
| what AIHA react more with room temperature or higher? | Warm-reactive autoantibody and drug-related autoantibody |
| Which AIHA react more with room temperature or below? | cold-reactive autoantibody and paroxysmal Cold hemoglobinemia |
| What is the most common specificity of warm-reactive autoantibody? | anti-Rh |
| What is the most common specificity of cold reactive autoantibody? | anti-I and anti-i |
| what is the most common specificity of paroxysmal cold hemoglobinemia? | anti-P |
| what is the most common specificity of drug-related autoantibody? | anti-e-like |
| what is the site of destruction in warm-reactive autoantibody? | mostly spleen, sometimes liver |
| what is the site of destruction in cold reactive autoantibody? | mostly liver, rarely intravascular |
| What is the site of destruction in paroxysmal cold hemoglobinemia? | intravascular |
| What is the site of destruction in drug-related autoantibody? | intravascular and spleen |
Created by:
wulfmannwarrior
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