Chapter 11 Overview of the Routine Blood Bank Laboratory

Overview of the Routine Blood Bank Laboratory

• Consists of component preparation and storage, donor processing, product labeling, main laboratory, and reference laboratory areas.
• It's a specialized and highly regulated part of laboratory medicine, involving scientific advancements, technological innovation, and changes in regulations.
• It’s a place where blood and blood products are tested with every task scrutinized for quality and safety.
• The FDA regulates it, and the AABB accredits it.

Organization of Blood Banks

• Defined as a facility for collecting, storing, processing, and distributing human blood and blood products for transfusion.
• Functions within a larger organization such as a hospital or community blood center.

Component Preparation and Storage

• Involves separation of whole blood into packed RBCs, plasma, platelets, and cryoprecipitate.
• Requires storage of blood products at specific temperatures and may include apheresis procedures

Blood Banks With Collection Facilities

• Collects their own units of whole blood, optimizing resource use by separating blood into components like packed red blood cells (RBCs), platelets, fresh frozen plasma (FFP), frozen plasma prepared within 24 hours of collection (FP24), and cryoprecipitate.
• After collection, whole blood must be cooled to 20°C to 24°C if platelets are to be prepared or cooled to 1°C to 10°C if the unit is to be processed for frozen plasma
• FFP must be prepared within 8 hours of collection of whole blood, whereas FP24 may be prepared up to 24 hours following collection of the whole blood unit.
• Platelets may be prepared from whole blood stored at room temperature for up to 24 hours after the whole blood unit is collected.

Apheresis

• A procedure where a donor's blood is removed, anticoagulated, and separated into components (platelets, plasma, granulocytes, red blood cells) by centrifugation in a machine and remaining portion is returned to the donor
• A donor's blood is removed, anticoagulated, and transported directly to an apheresis machine.
• Blood separated into platelets, plasma, granulocytes, red blood cells through centrifugation in the machine.
• Remaining portion of the blood is returned to the donor.

Blood Banks Without Collection Facilities

• Blood banks that depend on an outside source for their blood supplies usually receive their products in component form
• May need to modify products such as preparing washed RBCs for patients deficient in IgA using automated cell washers.
• Automated cell washers introduce a unit of blood into a sterile disposable bowl that has tubing connected to a normal saline solution.
• Washers mix cells and saline, centrifuge the mixture, and remove the supernatant through waste tubing.
• Platelet concentrates and cryoprecipitate may be pooled for easier administration.
• Sterile connecting devices (STCDs) create sterile welds between two pieces of compatible tubing, permitting sterile connection of various containers.

Equipment

• Platelet rotators that prevent the formation of platelet aggregates and optimize the exchange of gases for platelet survival.
• Sterile docking devices which create an entry point into donor units, without affecting the date

Donor Processing

• Donor units tested for ABO and Rh
• Antibody screen
• Serologic test for syphilis
• Transfusion-transmitted viruses

Product Labeling

• All blood products must be labelled
• Products stored at proper temperatures

Donor Processing Tests

• Separate tubes of blood are collected from the donor at the time of donation for the required tests that must be performed
• Includes ABO and Rh, Antibody screen, Serologic test for syphilis, Transfusion-transmitted viruses

Product Labeling

• Occurs after careful review of test results deems the unit suitable for transfusion.
• Requirements include no discrepancies in ABO and Rh testing, absence of detectable antibodies, nonreactive viral marker tests, and nonreactive syphilis test
• RBCs and components are labeled with appropriate ABO, Rh, and expiration date and stored at proper temperatures.
• The ABO of each RBC-containing product received must be reconfirmed.
• The Rh type of all Rh-negative units must be reconfirmed because of the potential sensitization that may occur if Rh-positive blood is transfused to an Rh-negative patient.

Main Laboratory

• Patient care is the primary mission of the main laboratory
• Is resposible for deterimine compatibility between patients requiring transfusion and blood for transfusion,
• Strict policies involving sample collection, testing, and identification are essential.
• Patient samples tested for includes ABO an Rh, Antibody screen, Crossmatch, DAT, Prenatal evaluation Postpartum evaluation, Cord blood studies.

Sample Collection and Acceptance

• Proper patient identification is crucial for any specimen used in blood bank testing
• Requires a minimum of two identifiers such as the patient's full name and date of birth or medical record number

Routine Testing

• Once a patient sample has been judged acceptable, the testing requested by the patient's physician can be performed.
• Consists of type and screen, type and crossmatch, prenatal evaluation, postpartum evaluation and cord blood studies

Type and Screen

• A testing protocol in which ABO and Rh testing and antibody screening are performed using a current patient specimen.
• In the absence of a positive antibody screen, blood can be released using an abbreviated crossmatch if the patient has no history of significant antibodies.

Type and Crossmatch

• Consists of ABO and Rh testing and antibody screening,
• If the result of the antibody screen is positive, the antibody must be identified, and compatible units are reserved for the patient.
• Performed on a current patient specimen.
• The same specimen is also used to crossmatch with a segment of the unit intended for transfusion.

Prenatal Evaluation

• Serologic testing of obstetric patients essential in the prevention and treatment of hemolytic disease of the fetus and newborn (HDFN).
• Includes maternal blood samples which are evaluatied during pregnancy to determine the presence of serum antibodies that can potentially cause HDFN.
• If the woman is classified as Rh-D negative, may be a candidate for antenatal Rh-immune globulin unless they have actively acquired anti-D.
• The result of the antibody screen is positive, the antibody must be identified

Postpartum Evaluation

• All women admitted for delivery test to determine their Rh status.
• If the mother is Rh-negative and her baby is Rh-positive, the maternal sample is further evaluated to detect a feto-maternal hemorrhage (FMH) in excess of 30 mL

Issue of Blood Products

• After all pretransfusion testing has been completed, blood components may be released for Transfusion to the recipient. -A form is needed with two patient identifiers.
• The blood product unit must be inspected
• The forms must also be inspected
• FFP may be thawed in a water bath , platelet concentrates may be pooled into a single bag, and a packed RBC may need to be irradiated.

Reference Laboratory

• The problem-solving section of the transfusion service ensuring discrepancies detected in routine testing are resolved.
• The lab investigates patient's diagnosis, age, pregnancy, drug, and transfusion history.

Antibody Identification

• A positive antibody screen in the absence of a positive auto-control or DAT result indicates possible alloantibody immunization by means of blood transfusion or pregnancy.
• Antibody investigation may include antibody identification panels, neutralization using substances such as plasma, saliva, urine, or human milk, antigen typing, titration, IgG subclassing

ABO Discrepancies

• All inconsistencies between forward and reverse grouping must be resolved before an ABO interpretation can be made.
• ABO investigations may include variations in incubation times and temperatures, Testing with A₂ cells or anti-A₁ lectin, room temperature antibody identification

Transfusion Reaction Investigations

• Any adverse reactions to transfusion must be investigated to determine if the reaction is antibody-mediated
• At a minimum, investigation should include an ABO, Rh, DAT, and visual check for hemolysis using a post-transfusion sample.

Personnel Requirements

• Blood bank laboratories must employ personnel who are qualified by education, training, or experience.

Standard Operating Procedures

• Orientation to a blood bank laboratory begins with reading the standard operating procedure (SOP) manuals

Transfusion Process Oversight

• Involves training for blood administration and observation of a patient and the blood bank often directs said training.