Compatibility Testing • A.K.A. crossmatch • Defined as all the steps necessary in I.D. and testing of or for potential transfusion in an attempt to provide blood product that survives in vivo and provides a therapeutic effect. • Includes: • Recipient Identification • Sample collection and handling • Pretransfusion test
Steps involved: • Accurate patient identification • Proper collection and handling • Review of Patient history • ABO/Rh donor unit • ABO/Rh and Antibody screen of recipient. • X-match of recipient and donor unit • If identified clinically significant antibody, screen unit for antigen for transfusion.
Two types of crossmatches: • Major: Patient’s serum crossed with donor RBC. • Minor: Patients RBC crossed with donor serum. Major is the one we perform in transfusion medicine. Incompatible crossmatch indicated by hemolysis or agglutination at any phase of testing.
Transfuse blood product: RBC vs. whole blood. • Historical Overview: • 1st venous transfusion- William Harvey 1628-result in patient death due to the lack of understanding of the ABO compatibility. • 1920 and 30’s discussion of performing major and minor X-match. • AABB deemed the minor x-match unnessary-1976. • Wiener – suggested tube method over slide- 1940, along with the discovery of Rh factor and the need for 37ºC, enhancement media and AHG during x-match testing. • 1980 movement toward the abbreviated or IS crossmatch. • 1990 computer and advanced technology (gel and microplate)
Purpose of X-match: • Prevent transfusion reaction. • Maximize in vivo survival of blood product. • Check records and previous testing. • Check recipient history or development of antibodies. • Design to detect and eliminate donor units that are unlikely to survive once transfused. • Increase blood volume- 1 unit of RBC increase Hemoglobin 1g/dl and Hematocrit 3%.
Limitations: Compatibility in vitro • does not guarantee a successful transfusion. • does not guarantee a optimal survival of blood product. • Delayed reactions may occur. • Reaction may be febrile to severe.
Recipient Blood sample: • Properly labeled *accuracy is essential* • Specimen (serum or plasma) • Samples • Must be collected within 3 days of transfusion (limitation previous transfusion, multiple transfusions or pregnancy). • Sample must not contain any hemolysis.
AABB standards: (minimum labeling requirements) • Positively I.D patient. • Patient states name. • Tubes labeled at the patient side: • Name as it printed on the request, armband and label, unique I.D. #, date and time of collection, phlebotomist initials. • Information must match.
AABB requires comparison of test results if patient has past demographics. • Repeat Testing: • Confirm ABO/Rh of all donor units and recipient. • Any discrepancy with the label and test results, the donor unit is rejected.
Standards and Regulations: • AABB and FDA are the 2 principle organizations that apply standard to blood baking and transfusion medicine. • AABB: require that all crossmatch procedures: • always be performed using the recipient serum and donor cells from a segment attached to the original unit. • Technique used to demonstrate ABO/Rh incompatibility and clinically significant antibodies.
Crossmatch procedure: • 3 phases that may be utilized. • Immediate Spin (not useful in detecting all your antibodies, only utilized in emergency situations) • Anti-human globulin ( used in most facilities today) • Electronic (computer matches up data) Most facilities use AHG in combination with electronic information.
Tagging, Inspecting and Issuing the blood: • Once compatibility establish – we have to tag or reserve the unit for the recipient. • Tag: • Clearly state name and I.D.# • Name of the product • Donor # • Expiration date • Interpretation of the crossmatch. Box 8-3, 8-4
Reissuing unit of unused blood products: • Only if temperature is monitored (1-10ºC) • Unit not entered or compromised • Returned within 30 minutes of original issue time. Very important to follow protocol of facility and the AABB standards for blood product usage.
Problem solving (Table 8-1) • ABO errors • Unexpected antibody Primary cause of incompatibility. Special topics: • Emergency Release situation • O negative or AB plasma • Need pretransfusion sample • After issue of blood complete the crossmatch work-up. Box 8-5 Emergency release requirements
Massive transfusion: • Total volume exchange of blood through transfusion within 24 hours. • Transfusion exceeds total blood volume (10-12 units) • New sample needed for further crossmatch procedures. • For both emergency situations and massive transfusion want most compatible, least incompatible blood group. Prefer type specific, if not known or available at least Rh negative. (Type O =)
Type and Screen protocols: • May be performed on patient undergoing non invasive procedures. • If clinically significant antibody present must transfuse antigen negative product. • Type and screen is on record so if problem occurs, we know the blood type of the patient and if there is an antibody present we should have it identified.
Crossmatch of Autologous Units: involves same steps of a routine crossmatch with the exception of using the patients own donor unit instead of a unit from the general stock. • Compatibility testing for infants: • Less than 4 months old- no antibody production, antibodies are from the maternal origin.
ABO/RH test- we omit serum test- no antibodies • If we perform antibody screen- use maternal blood along with infant to verify presents of suspected antibody. If clinically significant antibody identified, must give antigen negative product. • Pediatric units available commercially- very expensive. • Split units for pediatric use.
Pre-transfusion on non-RBC products: • Other products include Frozen plasma, platelets concentrates, and cryoprecipitate. (contain little or no RBC)- don’t usually require crossmatch procedure. • Platelet pheresis and granulocyte concentrates may contain RBC- need crossmatched.
Donor screening- 3 Phases • Registration • Health History interview • Physical exam Registration: Documentation of individual on permanent records- retained indefinitely. • Keep up eligibility status, past donations and donor history on database except for 1st time donor. Bullets on pg. 206
Pre-interview educational material: Prior to any donation must give educational material which includes information on : • Risk of diseases transmission. • Signs • Symptoms • High-risk behavior associated with HIV/AIDS
Health History: • Protects both the donor and recipient • Determine donor suitable • FDA and AABB set criteria for health • 2 types of questions • Questions to protect the donor • Questions to protect the recipient.
Donor deferral involve questions regarding general health, previous surgeries, bleeding and pregnancy • Temporary deferred • 6 week deferral • 12 month deferral • Medical director deferral • Permanent deferral Table 9-2, pg 216, box 9-1 and 9-2
Physical exam: • Donor should appear in general good health • H/H requirements 12.5 g/dl and 38 % Determined by capillary tube or CuSO4 • Temperature: 37.5 °C or 99.5 °F • Blood pressure <180/100 • Pulse: 50-100 • Weight 110lb or 50kg- can donate up to 525ml
Confidential unit exclusion: method that allows donor to exclude their unit from the general population in a confidential manner • Bar code labels Informed consent- written consent from donor for procedure and use of blood products
Phlebotomy: important Identification confirmed before venipuncture. • Bag labeling: Primary bag with satellite bags for separated products. • Adverse reactions (table 9-4) • Post donation care
Special Blood collection: • Autologous- used for planned surgeries, donor donates own blood for use. (advantages vs. disadvantages ,box 9-3) • Special operative collection: • Preoperative • Intraoperative Hemodilution • Intraoperative • Postoperative
Directed Donor: Donor requirements and testing must be met as usual. Hemapharesis: (Blood , to move) Whole blood is collected or removed from a donor, separated by mechanical device and the rest is returned to the donor. • Leukapheresis • Plateletpheresis • Plasmapheresis
Therapeutic Phlebotomy: Intentional removal of blood for therapeutic purpose, used to treat certain disease processes.
Infectious disease testing involves various method: • Indirect EIA • Sandwich EIA • Competitive EIA Utilize internal and external controls to verify reactivity or lack of. Need to know the test that are performed on donor units. (table 10-2) Western Blot test Look back method
Donor blood collected as whole blood then separated out into different products. • For optimal storage and patient needs • FDA regulates all processes in collection, separation and distribution. • Blood collection bag that consist of 2 systems. • Open system • Closed system
Collection process is determined by the product that is being collected for. • Different anticoagulants that are used for different products. • If less than 350ml collected in a unit, must reduce the anticoagulant. • Anticoagulants used: • Dextrose • Adenine • Citrate • Sodium biphosphate
Preservatives added to increase shelf life: • Citrate Phosphate dextrose-CPD. • Citrate phosphate-2 dextrose- CP2D • Citrate phosphate dextrose adenine-1 CPDA-1 CPD and CP2D: storage 21 days @ 1-6°C CPDA-1: storage 35 days @ 1-6°C
Additives: added to enhance survival and function of RBC. • Additive solution: AS-1, AS-3 and AS-5 • AS-1 and AS-5 contain mannitol, stabilizing agent. • AS-3 : citrate and phosphate added within 72 hours- extends storage to 42 days. • Rejuvenation solution- restores 2,3 DPG in RBC
Blood component Preparation: • Unit is centrifuged (time and speed is determined by product collected) • Light spin vs. Heavy Spin • Plasma- frozen for Fresh Frozen plasma (FFP), Stored within 8 hrs. and @ -18°C for 1 year or @ -65°C for 7 yrs.
Whole Blood: unmodified contains RBC, WBC, Platelets, Plasma and anticoagulant. • Problem with volume, must be ABO identical, has limited use. • Packed Red Blood Cells (PRBC) • Replaced Whole blood • Rich in HGB • Used most often today to replace circulating RBC volume. • 1 unit increase HGB 1g/dl and HCT 3 %.
Leukocyte Reduced Red Blood Cells (LRBC). • RBC washed or filtered to remove WBC. • Filter: 170 micron or Leuko-reducing filter • Reduces the transfer of WBC along with CMV infection that may be present on the WBC.
Frozen RBC: • Freezing extends storage-10 years • Use glycerol to protect the cells • Not a common practice • Deglycerolized RBC: • The removal of glycerol from frozen RBC • Wash the unit with 12% , 1.6% and 0.9 % saline. • Unit becomes an Open system and must be transfused within 24 hours.
Washed RBC • Process of washing the unit with normal saline • Used on intrauterine or infant transfusions • Prevents exposure • Irradiated RBC • Used to prevent GVHD • Rid the unit of most on the HLA cells • Expiration of unit is changed to 28 days on irradiated RBC.
Platelets: • Used for essential hemostasis • Not utilized in disease effected platelets. • Do not require cross-match, but should be type specific. • Platelet concentrate • Pooled platelets • Platelet Pheresis
Fresh Frozen Plasma use: • Contains coagulation factors • Indicated for: • Bleeding patients who required Factors II, V, VII, X, XI • Patients on anticoagulants need surgery or are bleeding. • Treat TTP or HUS • Bleeding related to liver disease • Deficiency of a Factor • DIC
Thawing FFP • Performed in water bath @ 37°C for 30-45 minutes in protective wrap. • Store @ 1-6°C and transfuse within 24 hrs. • Cross match not necessary • Solvent detergent treated plasma
Cryoprecipitate Antihemophilic Factor: • Product of FFP • Contains most of the Coag Factors needed by hemophiliac patients. • VWF, Fibrinogen, Factor VIII, Fibronectin • CRYO is used primarily as supplement for patients def. in Factor VIII and Fibrinogen • Pooled Cryoprecipitant
Granulocytic Pheresis: • Collection of granulocytes • Used to increase WBC neutrophils • Crossmatch needed to prevent GVHD Labeling of all products use uniform guideline implemented by FDA. Any additional process to the unit must be identified. Storage is essential. Transport of products is checked and monitored.
Administration of Blood products: • Requirements for safe transfuse include: • Positive ID (Check #’s and name) • Observe patient for 1st 15 minutes and every 30 minutes thereafter. • Use 0.9% saline with transfusion • Use 170 filter and or Leukoreduce filter • Time limit, infuse within 4 hrs, if > 4 hrs split unit • Documentation of every step.