Clin Diagnostics
Terms
undefined, object
copy deck
- what percent of americans donate blood?
- 5%
- how many pints of blood do men have? women?
- 12 pints; 9 pints
- What are the general guidelines for donating blood
-
- > 17 years old
- >110 lbs.
- haven't donated in last 56 days
- "healthy" (feel well and able to perform normal activities)
- if chronically ill need to be on treatment and the condition needs to be undercontrol - Temporarily Deferred from Donation
-
-heart attack or cardiac surgery in last 6-12 mon.
-malaria in last 3 yrs. or travel to an endemic area
-blood transfusion w/in year
-tattoo or piercing w/in year
-household contact with a person who has hepatitis
-not feeling well on the day of donation
-antibiotics in the last 72 hrs.
-low blood cell count - Permanently Deferred
-
-Chemo or radiation to treat some types of cancers
-hepatitis at age 11 yrs. or older
-high risk of having HIV due to IV drug use or sexual contact - What is the nucleic acid amplification testing (NAT) used for?
- detects genetics material of viruses for HIV-1 and HCV, WNV
- Autologous transfusions
- blood donor and recipient are the same
- Allogenic transfusions
- blood transferred to someone other than the donor
- preoperative donation
-
Patients can make autologous donations up to 72 hrs. prior to surgery
44% are unused by the donor and are discarded - Blood Type A
-
Antigens on RBC--> A
Antibodies in serum--> Anti-B
Able to Receive--> A, O - Blood Type B
-
Antigens on RBC--> B
Antibodies in serum--> Anti-A
Able to Receive--> B, O - Blood Type AB
-
Antigens on RBC--> A and B
Antibodies in serum--> none
Able to Receive--> A, B, AB, O - Blood Type O
-
Antigens on RBC--> none
Antibodies in serum--> Anti-A and Anti-B
Able to Receive--> O - Rh Typing
- 2 alleles, fully expressed on fetal RBCs by 30 days gestation
- Rh standard of care
-
-Rh-Immune Globulin (RHIG, RhoGam)
-administered IM, should cover 15 mL of fetal RBCs
-should be given w/in 72 hrs. of delivery of Rh+ infant
-in case of abortion, assume Rh+ - Kleinhauer-Betke Test
-
-quantitative measurement of fetal blood in maternal blood
-20 ug/RhoGam/1mL fetal RBCs - When is whole blood used
- Used for Rh complications (limited to exchange transfusions of neonates)
- what is the shelf life of blood?
-
-35 days
-after storing 72 hrs. no viable platelets and negligible Factor VIII acitivity - Disadvantages of Whole blood transfusions
-
-Volume overload
-Incr. K, NH3, H+
-Exposes patient to larger number of antigens and antibodies
-Provides low level of clotting factors - Components of whole blood
-
RBCs
Platelets
Plasma
Cryoprecipitated AHF (factor VIII)
Granulocytes (transfused w/in 24 hrs. of collection) - How are packed RBCs obtained
- -obtained from centrifugation
- What is the shelf life of Packed RBCs
- storage up to 42 days, frozen up to 10 yrs.
- How much do packed RBCs help a patient
- one unit raises Hgb by 1 g/dL or HCT by 3%
- Are packed RBCs good for getting leukocytes
- no, they are poor; 70-85% removed by centrifugation, filters, or UV irradiation
- How are frozen packed RBCs used?
- cryoprotective agent is added, stored several years, thawed and washed prior to transfusion
- Deglycerolized RBCs
-
-removes nearly all leukocytes and plasma
-most expensive - Washed RBCs
-
-isotonic saline (IgA deficient patient)
-must be transfused within 24 hrs.
-contamination risk during processing - Advantage of Washed RBCs
-
-removes leukocytes--> febrile reaction
-Removes plasma--> allergic reactions
-same increase in Hct as packed RBCs - Platelets
-
-stored up to 5 days
-raises platelets by 50-60,000/uL in avg. size adult
-transfused platelet survive 3-5 days
-Use ABO compatible and Rh- for Rh- women of childbearing age - How many platelets do you need before surgery to avoid bleeding
- >50,000
- What type of platelets do you give to an immunocompromised pt.? to a pt. refractory to multiple transfusions?
-
-Irradiated platelets
-HLA-matched platelets - Fresh Frozen Plasma
-
-frozen w/in 6 hrs. of collection
-stored for up to 1 yr.
-use ABO compatible - Isolated deficiencies of fibrinogen, factor 8, or factor 13 better treated by what?
- cryoprecipitate
- Cryoprecipitate
-
-each bag exposes recipient to 10 donors
-Use ABO compatible - Compatibility Testing
-
-review old blood bank records
-ABO, Rh of pt. and donor
-Antibody screen of pt. and donor serums (ABO, Rh, Kell, Duffy, Kidd)
-crossmatch - Crossmatch (2 types)
-
Major--donor RBCs/Pt. serum
Minor--pt. RBCs/donor serum (less important) - Adverse Transfusion Reactions
-
-Hemolytic-intravascular vs -extravascular
-Febrile
-Allergic
-Delayed
-Hypothermia
-Hypocalcemia
-Hypo/hyper kalemia
-Graft vs host
-Disease transmission - If a transfusion reaction occurs what do you do?
-
-discontinue transfusion
-determine type of reaction
-check for hemolysis
-CBC, creatinine, coag studies