Lesson 8: SPECIAL COLLECTIONS and POINT-OF-CARE TESTING

• Are non-routine laboratory tests that may not only involve additional preparation and procedure, but may require other specimens such as urine or feces. These can be applied for special cases such as blood donations.

  Special collection procedures
• Purpose: Determines the blood type and Rh factor

  Special requirement: None

  Blood Bank: Blood Type and Screen
• Purpose: Checks the compatibility between the donor's and the recipient's blood

  Special requirement: Patient's serum or plasma and donor's RBCs

  Blood Bank: Cross-Match Test
• Purpose: Determines the presence of infection, identifies the type of organism involved, and measures the extent of infection

  Special requirement: Blood volume should be 20 to 30 mL per culture with a minimum of 10 mL per draw for patients weighing more than 80 pounds. For infants, it should be only 1% to 4% of the total blood volume.

  Blood Culture
• Purpose: Evaluates the blood clotting

  Special requirement: Microclots are avoided by gently inverting anticoagulants tubes three or four times after collection


  Coagulation Test
• Purpose: Screens for diabetes and other metabolic disorders

  Special requirement: Must be obtained 2 hours after meal

  2-hour Postprandial Glucose
• Purpose: Diagnose problems in carbohydrate metabolism and checks the ability to metabolize glucose through the tolerance level

  Special requirement: 1 hour for gestational diabetes and 3 hours for other glucose metabolism evaluation

  Glucose Tolerance Test (GTT) and Oral Glucose Tolerance Test (OGTT)
• Purpose: Determines the lack of mucosal lactase which is responsible for conversion of lactose into glucose

  Special requirement: Same procedure as 2-hour GTT but an equal amount of lactose is substituted for glucose

  Lactose Tolerance Test
• Purpose: Verifies the probability that the patient fathered a particular child

  Special requirement: Follows the chain-of-custody protocal and specific identification procedures

  Paternity/Parentage Testing
• Purpose: Tests the drug levels at specific intervals to establish proper drug dosage and avoid toxicity

  Special requirement: Collection timing should include the peak and through levels

  Therapeutic Drug Monitoring
• Purpose: Treats polycythemia and hemochromatosis

  Special requirement: Involves withdrawal of approximately 500mL as part of the treatment

  Therapeutic Phlebotomy
• Purpose: Checks the presence of toxins in the blood, hair, urine, and other substances

  Special requirement: Toxins usually exist in very small amounts

  Toxicology test
• Purpose: Checks the presence of aluminum, arsenic, copper, lead, iron, and zinc

  Special requirement: Measured in small amounts

  Trace elements
• Is important in determining which blood product can be safely used for blood transfusion.

  Blood bank specimen
• In collecting blood bank specimen, use lavender-top or pink-top EDTA tube or a red-top non-additive glass as an alternative.
• Blood banks follow strict specimen identification and labeling procedures to ensure that there are no errors that could lead to incompatible blood product causing fatal reaction to the recipient of the blood.
• The following information must be included in Blood Bank Specimens:

  1. Full name including middle initial
  2. Hospital ID number
  3. Social Security number for outpatients
  4. Date of birth
  5. Date and time of collection
  6. Initials of phlebotomist

  Note: Room number and bed number are optional
• Blood banks can use special identification systems such as ID bracelet (self-carbon adhesive for specimen), blood ID band (linear bar-code), and patient identification check-blood administration.
• Blood banks also conduct tests in the laboraotry to ensure that the donated blood is safe for blood transfusion.
• Blood banks tests in blood transfusion include typing the blood for transfusion and screening for infectious diseases. The blood type (ABO) and Rh factor (+ or -) are determined, too.
• There are cases when there is a need to conduct a cross-match test to eliminate blood-related compatibility issues that may arise between patient and donor.
• The plasma or serum from the patient is mixed with the RBC of the donor to check for compatibility.
• Blood donor collection is done mainly for the purpose of blood transfusion.
• Blood is donated by volunteers in units.
• Phlebotomists involved in donor collection should have undergone training to acquire special skills particularly excellent venipuncture skills.
• Blood donors should be 17 to 66 years of age, with a minimum weight of 110 lbs.
• Blood donors must have completed the physical exam and declared their medical history.
• The medical history of blood donors are recorded, and a brief examination is conducted prior to the collection.
• All donor data are confidential.
• A written permission must be submitted by the donor for documentation purposes since all blood components of a unit must be traceable as part of the look-back program.
• The unit of blood can be separated into RBC's, plasma, and platelets but these should still be traceable to the donor.
• Under the look-back program, blood recipients need to be notified when the donor has been diagnosed positive for disease. The blood components are then verified and retrieved.
• There are also cases when there is an autologous donation in which the patients donate blood for their own use especially for elective surgeries.
• Autologous donation eliminates risks associated with blood transfusion
• After securing a written permission from the physician, blood can be collected within a minimum of 72 hours from the surgery schedule.
• Another special scenario is cell salvaging in which the blood of the patient is salvaged (during surgical procedure), washed, and re-infused after testing for residual free hemoglobin.
• The salvaged blood needs to be tested prior to infusion because a high free hemoglobin level means that too many RBC's were destroyed during the salvage process and reinfusion is not recommended because it will result in renal dysfunction.
• A blood culture is a test that checks the blood for pathogens for patients who have a fever of unknown origin (FUO).
• The test determines the existence of bacteria in the blood that results in bacteremia or the presence of microorganism and toxins in the blood that causes septicemia.
• The presence of microorganism and toxins in the blood that causes septicemia.