Lesson 8

• Special collection procedures


  • Blood Bank Specimens
  • Blood Cultures
  • Coagulation Specimens
  • 2-Hour Postprandial Glucose
  • Glucose Tolerance Test
  • Lactose Tolerance Test
  • Parental/Paternity Testing
  • Therapeutic Drug Monitoring
  • Therapeutic Phlebotomy
  • Toxicology Specimens
  • Trace Elements
• Blood Bank Specimens


  • Use of lavender or pink-top EDTA tubes
  • Labelling requirements: patient's full name, hospital ID, DOB, date/time of collection, phlebotomist's ID, room/bed no.
• Blood Type and Screen

  Determines patient's blood type (ABO) and Rh factor
• Cross-Matching


  1. Determines compatibility between donor's and recipient's blood

  2. Involves patient's serum/plasma and donor's RBCs

  3. Includes Human Leukocyte Antigen test
• Blood Donor Collection


  1. Screening and collecting blood for transfusion purposes

  2. Blood is collected from volunteers in amounts referred to as units

  3. Facilities are called Blood Donor Centers

  4. Follow AABB guidelines and FDA regulations

  5. Uses CPD or CPDA1 anticoagulant/preservative solutions
• Principles of Donor Unit Collection

  • Collected from large antecubital vein
  • Sterile, closed system with collection bag and tubing
  • Bag contains anticoagulant and preservative
  • Filled by gravity, typically 450 mL
• Lookback Program


  Requires notification to all blood recipients when a donor has turned positive for a transmissible disease
• Autologous Donation


  1. Person donates blood for their own use, usually for elective surgery

  2. Requirements: physician order, Hb ≥11 g/dL, Hct ≥33%, minimum 72 hours before surgery
• Bombay Phenotype


  Very rare blood type
• Female Hemoglobin


  12-13 g/dL
• Male Hemoglobin


  13-15 g/dL
• Cell Salvaging


  1. Collects, filters, and washes blood from surgical field to produce autologous blood for transfusion

  2. Salvaged blood should be tested for residual free hemoglobin before reinfusion
• Elective Surgery


  Surgery that can be scheduled in advance, may be for better quality of life or serious condition
• Blood Cultures


  1. Help determine presence and extent of infection, type of organism, and antibiotic susceptibility

  2. Specimens collected in special bottles containing nutrient broth

  3. ASM recommends 2-4 cultures, CLSI recommends 2 sets (aerobic and anaerobic)

  4. Skin antisepsis with 10% povidone iodine, 1-2% tincture of iodine, or chlorhexidine gluconate
• Media Inoculation Methods


  1. Direct inoculation, syringe inoculation, intermediate collection tube

  2. Blood culture specimens always collected first to prevent contamination
• Antimicrobial Neutralization Products


  • Presence of antimicrobial agent can inhibit microbial growth in blood culture bottles
  • FAN or ARD bottles used to neutralize antimicrobials
• Coagulation Specimens


  1. No need for clear discard tube before blue-top tube (except for other coagulation tests)

  2. Sodium citrate tubes, blood to anticoagulant ratio 9:1

  3. Use discard tube with butterfly method

  4. Never pour partially filled tubes together

  5. If delayed, centrifuge and freeze plasma

  6. For VADs, draw and discard 5 mL or 6x dead-space volume before collecting specimen
• 1. Hour Postprandial Glucose


  Screening test for diabetes and metabolic problems, also used to monitor insulin therapy
• Glucose Tolerance Test


  1. Evaluates body's ability to metabolize glucose

  2. Preparation: 150g CHO for 3 days, 8-16 hour fast, adult dose 75g, children 1g/kg
• Lactose Tolerance Test


  1. Determines if patient lacks the enzyme lactase to convert lactose

  2. Can be done with breath samples (Hydrogen breath test)
• Parental/Paternity Testing


  1. Uses DNA profiling to determine probability of genetic parent-child relationship

  2. Blood samples preferred for testing
• Oral Glucose Tolerance Test (OGTT)


  Evaluates the body's ability to metabolize glucose by monitoring the patient's tolerance to high levels of glucose without adverse effects
• Major disorders


  • Hyperglycemia
  • Hypoglycemia
• Preparation for OGTT


  1. 150 grams of carbohydrates for 3 days before the test

  2. Fast for 8-16 hours

  3. Adult dose - 75 g; children - 1 g /kg body weight
• Lactose Tolerance Test


  1. Used to determine if a patient lacks the enzyme (mucosal lactase) that is necessary to convert lactose, or milk sugar, into glucose and galactose

  2. Absence of the enzyme causes gastrointestinal distress and diarrhea

  3. Can be performed on breath samples (Hydrogen breath test)
• Parental/Paternity Testing


  Uses DNA profiling (also called genetic fingerprinting) to determine the probability that two specific individuals have a genetic parent–child relationship
• Paternity test vs maternity test
• Blood samples are preferred for testing; however, buccal (cheek) swabs are increasingly being used
• Blood sample testing includes ABO and Rh typing
• Therapeutic Drug Monitoring (TDM)


  A quantitative evaluation of circulating concentrations of drugs to ensure that a given drug dosage produces maximal therapeutic benefit and minimal toxic effects
• Principles of 2-Hour Postprandial Specimen Collection

  1. Patient fasts prior to the test

  2. Fasting glucose specimen may be collected before the start

  3. Patient eats a high-carbohydrate breakfast or given a measured dose of glucose beverage

  4. Nothing else consumed before the test

  5. Patient rests during the 2-hour waiting period, no exercise

  6. Blood glucose specimen collected 2 hours after the patient finishes eating
• Peak levels


  Screen for drug toxicity
• Trough levels


  Monitored to ensure that levels of the drug stay within the therapeutic range
• Therapeutic Phlebotomy


  1. Withdrawal of large volumes of blood usually measured by the unit or approximately 500 mL

  2. Used as a treatment for certain medical conditions such as polycythemia and hemochromatosis
• Polycythemia


  A disease involving the body's overproduction of RBCs
• Hemochromatosis


  A disease characterized by excess iron deposits in the tissues
• Causes of hemochromatosis


  • Genetic defect in iron metabolism
  • Multiple blood transfusions
  • Hemolytic disorders
  • Iron supplements
  • Excess iron intake from foods
• Clinical toxicology


  Concerned with the detection of toxins and treatment for the effects they produce
• Forensic toxicology


  Concerned with the legal consequences of toxin exposure, both intentional and accidental
• Specimens used in toxicology

  • Blood
  • Hair
  • Urine
  • Other body substances