Blood bank Information and Courses from MediaLab, Inc.

Antibody screening and antibody identification are critical components in blood bank testing. Clinically significant antibodies must be identified so that appropriate blood products are selected for transfusion and the risk of adverse reaction is minimized. Clinically significant antibodies are capable of causing transfusion reactions, hemolytic disease of the newborn and in severe cases, death.This course will discuss the techniques that are used by blood bank technologists to detect and identify various types of antibodies.

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.

Joe has worked in the Blood Bank for 10 years. He will retire next week and Sara will fill his position. One of the tasks that Joe routinely performed was replacing the 10 liter saline cube located on the technical workbench. However, Sara realizes that she cannot safely lift the 10 liter cube and place it on the benchtop.An employee's stature and lifting capabilities are important variables in a physical task. Since the employee cannot physically change, other solutions must be considered. This situation is easily resolved by changing the size of the container in use. Ergonomic solutionThe Blood Bank will begin using 5 liter saline cubes that can be easily lifted by all members of the staff. The Blood Bank will also acquire a cart or hand truck for other heavy items. This scenario demonstrates that a change in staff may require ergonomic action to prevent injury.

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

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.

PCR can be modified for the amplification of RNA with one additional step prior to the PCR process -- the addition of a retrovirus enzyme called reverse transcriptase. Reverse transcriptase is used to create a copy of DNA using the original RNA specimen. Though there are thermostable polymerases that have reverse transcriptase capabilities, they are not commonly used. Reverse transcriptase PCR (RT-PCR) is used for the detection of viruses, such as HIV, that have an RNA genome. RT-PCR methods provide early detection of infection, even before the formation of antibodies. Therefore, it is a particularly useful method for HIV and hepatitis C virus(HCV) detection in blood bank nucleic acid testing. In addition to testing for HIV and HCV, RT-PCR is also used for detection of Mycobacterium tuberculosis, cytomegalovirus (CMV), influenza A virus, and other microorganisms where the target is RNA.RT-PCR is commonly combined with real time PCR.

Most blood collection tubes contain an additive that either accelerates clotting of the blood (clot activator) or prevents the blood from clotting (anticoagulant). A tube that contains a clot activator will produce a serum sample when the blood is separated by centrifugation and a tube that contains an anticoagulant will produce a plasma sample after centrifugation. Some tests require the use of serum, some require plasma, and other tests require anticoagulated whole blood. The table below lists the most commonly used blood collection tubes. Tube cap color Additive Function of Additive Common laboratory tests Light-blue 3.2% Sodium citrate Prevents blood from clotting by binding calcium Coagulation Red or gold (mottled or "tiger" top used with some tubes is not shown) Serum tube with or without clot activator or gel Clot activator promotes blood clotting with glass or silica particles. Gel separates serum from cells. Chemistry, serology, immunology Green Sodium or lithium heparin with or without gel Prevents clotting by inhibiting thrombin and thromboplastin Stat and routine chemistry Lavender or pink Potassium EDTA Prevents clotting by binding calcium Hematology and blood bank Gray Sodium fluoride, and sodium or potassium oxalate Fluoride inhibits glycolysis, and oxalate prevents clotting by precipitating calcium. Glucose (especially when testing will be delayed), blood alcohol, lactic acid

The first component of therapy is to stop the transfusion immediately. Vital signs must be closely monitored. Management involves treatment of hypotension and disseminated intravascular coagulation (DIC). It is essential to maintain blood volume and adequate renal blood flow. Diuretics, substances that increase urine output, may be administered. If the patient enters renal failure, dialysis must be initiated rapidly. It is impossible to prevent all hemolytic transfusion reactions. The purpose of pre-transfusion compatibility testing is to decrease the probability of a hemolytic transfusion reaction by performing ABO/Rh testing, detecting and identifying alloantibodies, and crossmatching compatible blood. Human error, the most common cause of hemolytic transfusion reactions, cannot be completely eliminated. Steps must be taken to reduce the possibility of human error in identification of patient samples, donor units, and recipients. Each person involved in the transfusion process, from collection of the blood sample to administration of the donor unit, must carefully adhere to each step outlined in the standard operating procedures. All appropriate protocols must be followed. Some examples are: Technologist checks blood sample to ensure proper labeling. Patient's previous transfusion records are examined and all transfusion testing is performed correctly and accurately. Technologist ensures correct unit is released from the blood bank. Transfusionist ensures the recipient is correctly identified.There must be a mechanism in place to train and assess all personnel involved in the transfusion process.