Lesson 8

• Special collection procedures


  Non-routine laboratory tests that may not only involve additional preparation and procedure but may require other specimen such as urine or feces. These can be applied for special cases such as blood donation.
• List of Special Collection Procedures

  • Blood Bank: Blood type & Screen
  • Blood Bank: Cross-match test
  • Blood Culture
  • Coagulation test
  • 2-hour Postprandial glucose
  • Glucose Tolerance Test (GTT) and Oral Glucose Tolerance Test (OGTT)
  • Lactose Tolerance Test
  • Paternity/Parentage Testing
  • Therapeutic Drug Monitoring
  • Therapeutic Phlebotomy
  • Toxicology test
  • Trace elements

  
• Blood Bank: Blood type & Screen


  Determines the blood type and Rh factor
• Blood Bank: Cross-match test


  Checks the compatibility of the blood between the donor and the recipient
• Blood Culture


  Determines the presence of infection, identifies the type organism involved and measure the extent of infection
• Coagulation test


  Evaluates the blood clotting function
• 1. hour Postprandial glucose


  Screening for diabetes and other metabolic disorders
• Glucose Tolerance Test (GTT) and Oral Glucose Tolerance Test (OGTT)


  Diagnose problems in carbohydrate metabolism and checks the ability to metabolize glucose thru the tolerance level
• Lactose Tolerance Test


  Determine the lack of mucosal lactase which is responsible for conversion of lactose into glucose
• Paternity/Parentage Testing


  Verifies the probability that the patient fathered a particular child
• Therapeutic Drug Monitoring


  Tests the drug levels at specific interval to establish proper drug dosage and avoid toxicity
• Therapeutic Phlebotomy


  Used as treatment to polycythemia and hemochromatosis
• Toxicology test


  Checks the presence of toxins in the blood, hair, urine, and other substances
• Trace elements


  Checks for presence of aluminum, arsenic, copper, lead, iron, and zinc
• 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.

  
• Microclots are avoided by gently inverting anticoagulants tubes three or four times from collection.
• Must be obtained 2 hours after meal
• 1 hour for gestational diabetes and 3 hours for other glucose metabolism evaluation.
• Same procedure as 2-hour GTT but an equal amount of lactose is substituted for glucose.
• Follows the chain-of custody protocol and specific identification procedures.
• Collection timing should include the peak and trough level.
• Involves withdrawal of approximately 500 mL as part of the treatment.
• Toxins usually exist in very small amounts
• Measured in small amounts
• Patient Identification


  • Full name including middle initial
  • Hospital ID Number
  • Social Security Number for outpatients
  • Date of Birth
  • Date & time of collection
  • Initials of the phlebotomist
• Room number and bed number is optional.
• Blood bank identification systems

  • ID bracelet (self-carbon adhesive for specimen)
  • Blood ID band (linear bar-code)
  • Siemens Patient Identification check-blood administration

  
• Screening for blood transfusion

  • Typing the blood for ABO and Rh factor
  • Screening for infectious diseases
• Cross-match test


  Eliminate blood related compatibility issues that may arise between the patient and the donor
• Blood donor requirements


  • 17 to 66 years of age
  • Minimum weight of 110 lbs
  • Completed physical exam
  • Declared medical history
• Autologous donation


  Patient donates blood for his own use especially for elective surgeries
• Cell salvaging


  Blood of the patient is salvaged (during surgical procedure), washed and re-infused after testing for residual free hemoglobin

  
• Blood culture


  Test that checks the blood for pathogens for patients who have a fever of unknown origin (FUO)
• Bacteremia and septicemia


  Presence of bacteria and microorganisms in the blood
• Blood Culture Collection Procedure

  1. Identify the patient

  2. Select the venipuncture site and release the tourniquet

  3. Assemble the equipment and follow proper aseptic technique

  4. Perform the friction rub

  5. Wait for 30 seconds

  6. Open the culture bottle

  7. Clean the bottle stopper

  8. Check the fill lines on the bottle

  9. Tourniquet should be reapplied and perform the venipuncture

  10. Inoculate the medium

  11. Mix the blood with the medium

  12. Clean the patient's skin if iodine is used

  13. Observe proper labeling procedures

  14. Discard used and contaminated materials

  15. Thank the patient

  16. Transport the specimen promptly

  
• Media Inoculation Methods


  • Directly into the bottle (during collection)
  • Collected in a syringe (after collection)
  • Through an intermediate collection tube (in the laboratory)
• Coagulation tests


  Prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin time (TT)
• Coagulation Specimen Collection and Handling

  1. Draw a "clear" tube with 1-2 mL which is discarded prior to collection

  2. Collect the blood specimen using a light blue top with 3.2% citrate tube with the correct (9:1) blood to coagulant ratio

  3. Invert the tubes gently 3 to 4 times immediately after collection

  4. Collect the coagulation sample second when an evacuated tube system is used

  5. Flush the line with 5 mL of saline for draws using indwelling catheter

  6. Adjust the concentration of the sodium citrate for patients with above 55% hematocritt values

  7. Transport the specimen to the laboratory immediately or centrifuge and freeze the plasma if unable to reach within 4 hours
• 1. hour Postprandrial Glucose Procedure

  1. Introduce a high-carbohydrate diet 2 to 3 earlier

  2. Fast the patient at least 10 hours prior to the test

  3. Collect fasting glucose specimen before the start

  4. Give a special breakfast containing an equivalent of 100g glucose or a glucose beverage

  5. Collect blood glucose specimen 2 hours after the meal
• Glucose Tolerance Test (GTT) Procedure

  1. Eat balanced meal containing approximately 150 grams of carbohydrates for 3 days and fast for 12 to 16 hours before the scheduled test

  2. Collect the fasting specimen and check the glucose level

  3. Collect fasting urine specimen if ordered

  4. Give the glucose beverage dose

  5. Record the time when the drink was finished and start timing the test

  6. Collect specimens within 30 minutes, 1 hour, 2 hours and so forth

  7. Provide a copy of the collection time to the patient

  8. Collect other specimens such as urine to coincide with the computed collection time

  9. Write the exact time collected and the time interval on the label

  10. Transport the specimen immediately or within 2 hours