Transfusion Information and Courses from MediaLab, Inc.
These are the MediaLab courses that cover Transfusion and links to relevant pages within the course.
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| Alpha Thalassemia Intermedia Alpha thalassemia intermedia (Hemoglobin H Disease) is a result from a deletion of three out of four alpha chain loci. Infants born with alpha thalassemia intermedia appear normal at birth but often develop anemia and splenomegaly by the end of their first year. Hepatomegaly is not a common finding and there may be some association with mental retardation. Due to the hemolytic nature of this anemia, there may be an increase in respiratory infections, leg ulcers and gallstones. Skeletal changes are not commonly seen in hemoglobin H disease. Every ethnic group can have occurrences of hemoglobin H disease; but it is most often seen in Southeast Asian, the Middle East and the Mediterranean islands. Development and life expectancy are usually normal, but some may require splenectomy and transfusion therapy. | View Page |
| Clinical Significance No blood is found in the urine of healthy individuals although samples from menstruating females, frequently, but not always, test positive for blood. Hematuria is associated with renal or genital urinary disorders in which the bleeding is the result of irritation to the involved organs or trauma. Examples include renal calculi, pyelonephritis, glomerulonephritis, tumors, trauma or exposure to toxic chemicals or drugs and/or strenuous exercise. Hemoglobinuria may be due to the lysis of red cells within the urinary tract. If it is caused by intravascular hemolysis, the hemoglobin is then filtered through the glomeruli. In the normal individual, the hemoglobin molecule attaches to haptoglobin and in this way bypasses the kidney filtration system. When the hemoglobin/haptoglobin system is overwhelmed, as in cases of hemolytic anemia, severe burns, transfusion reaction, infection or strenuous exercise, hemoglobin passes into the urine. | View Page |
| The most common cause of severe life threatening hemolytic transfusion reactions is: | View Page |
| Which one of the following is not a benefit of using packed RBCs: | View Page |
| Which of the following is most commonly associated with febrile non-hemolytic transfusion reactions: | View Page |
| Deglycerolized red cells are most effectively used to: | View Page |
| A delayed hemolytic transfusion reaction is most likely to be the result of which of the following antibodies: | View Page |
| Which of the following types of packed RBCs could be transfused to a group O patient: | View Page |
| Which of the following options gives in order from most to least important, the factors you would use to select blood for a transfusion: | View Page |
| An urticarial reaction is characterized by: | View Page |
| The use of the direct antiglobulin test is indicated in all the following except: | View Page |
| After transfusion, a red cell sample from the donor unit, and the recipient's blood sample, must be kept for: | View Page |
| Which of the following conditions is most frequently associated with anti-I: | View Page |
| Which of the following statements best describes Rh antibodies: | View Page |
| Which one of the following statements about directed donations is true: | View Page |
| Autologous blood must be tested for which of the following before transfusion: | View Page |
| Gamma irradiation of cellular blood components is required in which of the following situations: | View Page |
| Antibodies to which of the following are the most frequent cause of febrile transfusion reactions: | View Page |
| How long may blood be stored using CPDA-1 preservative prior to transfusion? | View Page |
| The most severe acute hemolytic transfusions reactions are the result of which of the following: | View Page |
| Elevation in conjugated bilirubin is most likely to be found in which of the following conditions: | View Page |
| Increases in LD fractions 4 and 5 are indicative of: | View Page |
| Increase Marrow Iron Stores Markely increased stainable iron is present in this biopsy. Iron stores may be increased in sideroblastic anemia, chronic infections, hemochromatosis, hemosiderosis due to numerous blood transfusions, chronic hepatitis, cirrhosis, and uremia. | View Page |
| Importance of Understanding the ABO System While the predictability of ABO antibodies in persons lacking the corresponding antigen makes the ABO blood group system an easy one for testing purposes, it can be treacherous as far as transfusion is concerned. If a patient receives cells containing A or B antigens and his/her serum contains the corresponding antibody, the donor cells will be destroyed almost immediately with severe and sometimes fatal transfusion reaction. It is, therefore, of utmost importance to thoroughly understand the ABO blood group system. Compatibility of the ABO system is essential for all other pre-transfusion testing. | View Page |
| ABO Antibodies In most other blood group systems, antibody may be formed after an individual has been immunized by an antigen that is missing from his or her red cells; perhaps as the result of pregnancy or transfusion. In the ABO system, when the antigen is missing from the cells, the corresponding antibody will predictably be found in the serum and must be found before determining the ABO type. There are few exceptions to this rule and any exception must be explained before the true ABO blood type can be determined. | View Page |
| "Immune" ABO Antibodies A person exposed to a specific immunizing event may produce “immune” ABO antibodies of the same specificity as the “naturally” occurring antibody, but with different biological behavior. Such immunizing events include pregnancy with an ABO incompatible fetus or transfusion of ABO incompatible red cells. After immunization, the subject’s antibody may increase in titer and/or avidity, develop powerful hemolyzing properties, or become more active at 37ºC. | View Page |
| Immunoglobulin The predominant immunoglobulin class for the B antibodies produced by individuals with group A phenotype and the A antibodies produced by individuals with group B phenotype is IgM. Small quantities of IgG may also be present. IgG is the predominant immunoglobulin for the anti-A and anti-B antibodies found in individuals with group O phenotype. Infants of group O mothers are at higher risk for hemolytic disease of the newborn (HDN) than those born to mothers with group A or B because IgG immunoglobulins readily cross the placenta. IgM molecules do not readily cross the placenta because of their larger size. It is important to note that immune antibodies are usually IgG. Both naturally occurring and immune ABO antibodies are critically important in transfusion since both sensitize and usually hemolyze red cells with the corresponding antigen. | View Page |
| Which of the following is NOT a way in which "immune" ABO antibodies may be formed? | View Page |
| Automated Systems An increasing number of transfusion services are using automated blood banking systems. These systems may employ either solid phase or gel techniques. Use of automation may increase productivity, reduce costs, and, by decreasing the number of manual steps in the testing process, potentially reduce errors. | View Page |
| Example of an ABO discrepancy The composite image shown on the right illustrates the ABO typing reactions that were obtained for a patient. This particular case illustrates an ABO discrepancy. An ABO discrepancy occurs when the results of forward and reverse typing do not match. The reactions shown are described below in descending order:Patient red cells with reagent anti-A: negative reaction.Patient red cells with reagent anti-B: 4+ agglutination.Patient red cells with reagent anti-D: 4+ agglutination.Patient serum with reagent A1 red cells: negative reaction.Patient serum with reagent B red cells: negative reaction.This patient forward types as a group B, but reverse types as a group AB. (A group B patient should have anti-A. This patient demonstrates neither anti-A nor anti-B, similar to an AB patient). Further workup is necessary to determine the ABO type since the forward and back typing do not match. In this case, incubation at 40 C demonstrated the presence of weakened anti-A. The patient was therefore typed as group B. This case is an example of an ABO discrepancy which was due to a "missing" anti-A antibody. This could be due to old age, severe illness or immunosuppression. Although evaluation of ABO discrepancies is beyond the scope of this course, it is important to note that all ABO discrepancies must be resolved before blood products can be released for transfusion.This patient is Rh (D) positive, as evidenced by the strong agglutination of his cells with reagent anti-D antibody. | View Page |
| Description of Specialties (2) Specialists in immunohematology perform all testing prior to blood transfusions and work to prevent transfusion infections. They also investigate any post-transfusion reactions. This specialty includes all lab procedures performed in the specialty of histocompatibility.
Specialists in clinical chemistry analyze body fluids such as blood, urine, and spinal fluid to determine the chemical makeup, including the amount of carbohydrates, proteins, enzymes, and trace elements. The special covers urine microscopics and chemical evaluation of the liver, kidneys, lungs, heart, and other vital organ systems. This specialty also covers all testing performed in the specialties of radioassay and blood gas analysis.
Specialists in blood banking can perform all immunohematology testing as well as testing from the specialties of clinical chemistry, hematology and serology/immunology that relates to donor blood. Specialists in immunohematology, clinical chemistry, hematology, and serology / immunology may perform all tests in the blood banking specialty. | View Page |
| Sentinel Event Categories Sentinel Events are sentinels--they function as guards or watchkeepers. They indicate serious situations that require immediate attention:
Patient deathParalysisComaPermanent loss of functionAny procedure on the wrong patient, the wrong side of the body, or the wrong organ Hemolytic transfusion reaction involving major blood group incompatibility | View Page |
| JCAHO Sentinel Event ALERTS
Since 1998, JCAHO has issued 25 Sentinel Event ALERTS to the healthcare community. These publications include more than 50 evidence or expert-based recommendations for preventing adverse events.
Sentinel Event Alerts address various error reduction topics:
Transfusion reactionsInpatient suicideInfant abductionsWrong site surgery or other proceduresPatient falls
Laboratory professionals can be involved in all of these types of Sentinel Events.
JCAHO's first Sentinel Event ALERT addressed the common practice of storing concentrated potassium chloride solutions in hospital nursing units.
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| Types of Medical Errors
Medical errors usually belong to one or more of these categories: | View Page |
| Near Misses Near misses are also related to medical errors: Near misses are medical events that avert unwanted consequences.Someone or something identifies and corrects harmful influences before they cause adverse events.The medical community sometimes calls near misses “close calls.”
For example, a transfusion is stopped when the nurse discovers that the identification number on a unit of blood does not match the unit number on the requisition. This is a near miss for the patient receiving a transfusion of incompatible blood.
Near misses often provide important insight into new ways of preventing medical errors. In this case, a flaw in Blood Bank cross-checking systems is discovered so it can be prevented from causing a medical error. | View Page |
| Postanalytic Medical Errors Errors also occur after analyses are completed and reported.
Postanalytic errors begin with the medical professionals who receive test results, and they include interpretation of the results. These errors can occur at--the bedside, chair-side, hospital, clinic-- wherever the patient and the medical professional are located.
The possibility for postanalytic medical error continues through diagnosis and treatment procedures and processes.
These medical errors occur during the time after the laboratory reports test results.
Examples:
Wrong test value associated with patient
Wrong test interpretation
Wrong diagnosis
Wrong treatment
Laboratory professional might believe they are not associated with postanalytic medical errors, but they can. One deadly example is fatal hemolytic transfusion reactions involving laboratory errors.
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| Sources of Laboratory-Related Errors | View Page |
| These statements describe sources of laboratory-related errors. | View Page |
| Discussion When the results on Mr. John Ready were called to the nurse, she was very surprised that the result of his CBC was normal. The nurse explained to the lab tech that Mr. John Ready had a known diagnosis of lower GI bleeding. His hemoglobin had been very low for the past 24 hours because of the internal bleeding, and she thought it was very surprising that his hemoglobin had normalized so quickly without having received a blood transfusion. Mr. Ready’s doctor decided the patient should be redrawn to ensure a correct result. The nurse further questioned if the phlebotomist could possibly have drawn the wrong patient because earlier that day Mr. Ready had been moved to room 831, and room 825 was presently occupied by a patient named Walter Redding. If Julie had checked the patient’s armband, she would have realized that the patient in 825 was the wrong patient.Relevant topics:Importance of patient ID, Patient identification continued, Specimen labeling,
Specimen labeling Continued, Blood bank specimens
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| Concept of Hollister and similar systems The card has adhesive labels:for blood products,for the blood specimen, anda detachable armband stub,all with identical transfusion numbers. | View Page |
| Blood bank specimens Labeling of blood bank specimens is even more critical than labeling of other specimen types.If a patient gets the wrong unit of blood, a serious or even fatal transfusion reaction may occur. | View Page |
| The condition most likely associated with the peripheral blood picture in the photograph is: | View Page |
| Hb E disease (continued) The family (cited in the previous case history) was from a region of Thailand where the physician knew HbE carriers are prevalent. Homozygous hemoglobin E is common in Southeast Asia and presents with very mild anemia and seldom requires transfusion. Over 30 million people in the world are HbE carriers, making this abnormal hemoglobin almost as common as HbS. Hemoglobin E is uncommon in North America and in Europe, but with changing immigration patterns, hemoglobinopathy E cannot be ignored. Peripheral blood smear findings of target cells, microspherocytes, red cell hypochromia, a few red blood cell fragments, and nucleated red blood cells require evidence from hemoglobin electrophoresis to establish a diagnosis. Clinically, a very important and severe syndrome is hemoglobin E/beta thalassemia in which there is hemolysis requiring repeated transfusions. The patient has a severe anemia, low MCV (50's), and high RBC. This is characteristic of Hgb E/beta thalassemia. | View Page |
| Dimorphic RBC population Illustrated in the photomicrograph of a peripheral smear are two populations of erythrocytes. Approximately 50% of the erythrocytes are normal size and contain a full complement of hemoglobin. The patient had received blood transfusions. The transfused red blood cells are the normocytic, normochromic red cells. Admixed are microcytic erythrocytes and larger erythrocytes, some faintly mottled or smudged, suggestive of reticulocytes. This picture represents a hemolytic process with a reticulocyte response. A similar dimorphic red cell population appears following erythropoietin therapy. It is important to recognize when a population of cells in the peripheral smear is not in context with anticipated laboratory findings and the clinical situation. | View Page |
| A blood smear represented by the photograph was submitted for hematologic review. Based on the erythrocyte morphology and the accompanying histogram, which of the following choices is the most likely situation or condition? | View Page |
| Summary of Anisocytosis Anisocytosis is a general term reflecting increased variation in the size of red blood cells. The MCV will be within normal limits, but RDW will be increased. Variation usually affects a continuum of red cell sizes, but occasionally two distinct red cell populations can be observed(for example in sideroblastic anemia, or after red cell transfusion.) | View Page |