Special Considerations and Point of Care Testing

Special Procedures

• Most lab tests use blood from venipuncture or capillary puncture.
• Some tests require special collection procedures or other body fluids (e.g., feces, urine).

Blood Bank Specimens

• Provide information for safe blood transfusions.
• Strict protocol to prevent fatal transfusion errors.

Specimen Requirements

• Collect lavender or pink-top EDTA tubes; sometimes use nonadditive red-stoppered tube.

Identification & Labeling

• Extremely strict to prevent errors.
• Required labels include patient's full name, hospital ID, DOB, collection date/time, phlebotomist’s initials.

Special Identification Systems

• Use special blood bank ID systems like PDC Securline, Typenex Medical’s barcoded bands, and Siemens Patient Identification Check.

Type, Screen, and Cross-Match

• Determine blood type (ABO) and Rh factor.
• Crossmatch checks compatibility of patient plasma/serum with donor RBCs.

Blood Donor Collection

• Purpose is to collect blood for transfusions.
• Donor Blood Banks regulated by FDA.

Donor Eligibility

• Age: 17–66 years.
• Weight: At least 110 pounds.
• Requires medical history, physical exam, written consent, and confidentiality.

Principles of Donor Unit Collection

• Use large antecubital vein.
• Equipment: sterile needle, blood bag with anticoagulant.

Blood Cultures

• Diagnose bloodstream infections like bacteremia or septicemia.
• Requires special collection procedures.

Special Collection Requirements

• 2–4 blood cultures recommended.
• Skin antisepsis critical to prevent contamination.

Antimicrobial Neutralization Products

• FAN bottles contain activated charcoal.
• ARD bottles contain resin.

Coagulation Specimens

• Use sodium citrate tubes.
• Proper 9:1 blood-to-anticoagulant ratio needed for accuracy.

Glucose Tests

• 2-Hour Postprandial Glucose Test: Screens for diabetes.
• Glucose Tolerance Test: Diagnoses carbohydrate metabolism issues.
• Lactose Tolerance Test: Diagnoses lactose intolerance.

Paternity Testing

• Determines probability of biological fatherhood.
• Involves ABO/Rh typing and DNA profiling.

Therapeutic Drug Monitoring

• Ensures drug levels are effective but non-toxic.
• Timing of peak and trough levels is critical.

Therapeutic Phlebotomy

• Used to treat conditions by withdrawing blood.

Toxicology Specimens

• Detect toxins/poisons in various specimens.
• Chain of custody is important.

Point-of-Care Testing (POCT)

• Brings lab testing to the patient for convenience and fast results.
• Must comply with CLIA and OSHA guidelines.

Quality and Safety

• POCT results must match central lab tests.
• Continuous monitoring ensures quality.

Waived vs. Nonwaived Tests

• Waived tests require less stringent QC.

Electronic Quality Control (EQC)

• Detects instrument issues but not specimen handling errors.

Arterial Blood Gases and Electrolytes

• Arterial puncture is more hazardous than venipuncture.
• ABG Tests: Measure pH, PaCO₂, PaO₂, etc., for respiratory evaluation.

Personnel and Site Selection

• Performed by trained medical personnel.
• Sites include radial, brachial, femoral arteries.

Arterial Puncture Hazards

• Includes arteriospasm, nerve damage, hematoma, etc.

Sampling Errors

• Air bubbles, delay in analysis, improper mixing, and obtaining venous blood can cause errors.