Point of Care Testing Overview

NHA CCMA MOD 7 Point of Care Testing Overview

  • Definition of Laboratory Testing

    • Clinical laboratory testing applies scientific methods and analytical processes to support patient care, diagnosis, and monitoring.

    • Specimens are biological samples collected from patients in diverse settings, including hospital laboratories, reference labs, or ambulatory care facilities.

    • A specimen can include body fluid samples (blood, urine, cerebrospinal fluid), waste products (feces), or tissues (biopsies) for analysis.

    • Upon reaching the laboratory, specimens undergo a pre-analytical step where they are logged, processed (e.g., centrifuged), and assigned to the appropriate department.

  • Laboratory Departments and Their Functions

    • Each department utilizes specific methodologies and equipment based on the provider’s orders.

    • Manual vs. Automated: Simple tests may be performed manually (e.g., manual differential), while most high-volume tests utilize automated high-throughput throughput analyzers.

    • Result reporting includes the reference range (normal values) to assist providers in interpretation.

  • Scope of Practice for Medical Assistants

    • Core Responsibilities: Performing CLIA-waived point-of-care testing (POCT), collecting and processing specimens (venipuncture, capillary sticks), and conducting screening procedures.

    • Patient Education: MAs must provide clear, written or verbal instructions for at-home collections (e.g., stool samples or 24-hour urine) to ensure specimen integrity.

    • Compliance: Adhering to OSHA safety standards and HIPAA privacy regulations during all laboratory interactions.

  • Clinical Laboratory Improvement Amendments (CLIA)

    • Established in 19881988, CLIA defines the regulatory framework and standards for all laboratory testing to ensure accuracy and reliability regardless of where the test is performed.

    • The focus for MAs is primarily on "Waived Testing," which are simple procedures with a low risk for error.

Importance of Accurate Laboratory Requisitions and Specimen Collection

  • Role of Laboratory Requisitions

    • A requisition acts as a formal physician’s order and a billing document.

    • Medical Necessity: Must include an ICD-10-CM diagnosis code to justify the test for insurance reimbursement.

    • Inaccurately filled requisitions often result in the lab rejecting the specimen (QNS - Quantity Not Sufficient) or billing delays.

  • Labeling Specimens

    • Labeling must occur immediately after collection in the presence of the patient.

    • Required Elements:

      • Patient’s full legal name and unique identifier (e.g., DOB or MRN).

      • Date and exact time of collection (using military time where applicable).

      • Medical assistant’s initials.

      • Source or site of the specimen (e.g., "Left Antecubital").

    • Placement: Apply labels directly to the container, never the lid, as lids can be switched during processing.

Information Required on Completed Requisition

  • Components of a Laboratory Requisition

    • Demographics: Name, address, DOB, sex, telephone number, and insurance details.

    • Authentication: Provider’s signature or electronic equivalent.

    • Test Selection: Clear marking of specific tests (e.g., CBC with diff, Lipid panel).

    • Specimen Details: Source of specimen, collection method, and any relevant clinical data (e.g., "fasting specimen").

Departments in Clinical Laboratory

  • Types of Laboratory Testing

    • Urinalysis: Involves a three-part examination: Physical (color, clarity), Chemical (reagent strip for pH, glucose, protein), and Microscopic (cells, casts, bacteria).

    • Hematology: Studies the formed elements of blood. Includes the Complete Blood Count (CBC), hemoglobin (HgbHgb), hematocrit (HctHct), and coagulation tests like PT/INR.

    • Chemistry: Quantifies chemical substances in serum/plasma. Tests include metabolic panels (BMP/CMP), lipid profiles, electrolytes (Na+Na^{+}, K+K^{+}, Cl−Cl^{-}), and enzyme levels.

    • Microbiology: Identifies pathogens. Includes cultures (blood, urine, throat), sensitivity testing to determine antibiotic effectiveness, and parasitology.

    • Cytology: Specializes in detecting cellular changes, such as those found in Pap smears.

    • Blood Bank (Immunohematology): Performs blood typing, cross-matching, and processes components for transfusion.

Point-of-Care Testing (POCT)

  • Definition and Examples

    • POCT provides rapid results at the "bedside," allowing for immediate clinical decisions.

    • Pregnancy Testing: Detects human chorionic gonadotropin (hCGhCG). First morning urine is preferred due to higher concentration levels.

    • Rapid Streptococcus Testing: Throat swabs obtained from the peritonsillar area to detect Group A Strep.

    • Glucose Monitoring: Using a glucometer to manage diabetes.

    • Fecal Occult Blood Test (FOBT): Screening for hidden gastrointestinal bleeding.

CLIA-Waived Testing Overview

  • FDA Regulations and Testing Complexity

    • Waived Testing: Simplest tests with low risk of significant harm if performed incorrectly (e.g., dipstick urine, fecal occult blood).

    • Moderate Complexity: Includes many automated tests; requires a higher level of training and proficiency testing.

    • High Complexity: Includes molecular diagnostics and complex microbiology; performed by specialized laboratory scientists.

  • Quality Controls

    • Quality Assurance (QA): The overall system of monitoring the entire testing process to ensure quality.

    • Quality Control (QC): Specific procedures (e.g., running liquid controls) to ensure the test system is working correctly.

      • Internal controls: Built into the test kit (e.g., the "C" line on a rapid test).

      • External controls: Liquid samples with known values run to verify reagent integrity.

Specimen Collection Techniques and Requirements

  • Urine Specimen Collection Methods

    • Random: No preparation; used for general screening.

    • First Morning: Most concentrated; best for hCGhCG and protein analysis.

    • Clean-Catch Midstream: Required for cultures. The patient cleans the urinary meatus and voids a small amount into the toilet first to flush the urethra before collecting the sample.

    • 24-Hour Sample: Used to quantify substances (e.g., creatinine clearance). The patient discards the first void of day $1$, then collects all subsequent voids for $24$ hours, ending with the first void of day $2$.

Special Protocols and Safety

  • Chain of Custody: Used for legal specimens (drug screens, blood alcohol). Requires an unbroken trail of documentation from collection to disposal. The specimen is often sealed with tamper-evident tape.

  • Disposal: Follow the Bloodborne Pathogens Standard.

    • Biohazard bags (Red): For saturated gauze, used PPE, and non-sharp waste.

    • Sharps containers: For needles, glass slides, and lancets.

Specialty Testing

  • Spirometry: Measures lung volume; patient must provide a "maximal effort." Often requires three acceptable maneuvers to ensure consistency.

  • Vision Testing: Snellen chart is used at a distance of 2020 feet. Ishihara plates test for color vision deficiencies.

  • Allergy Testing: Skin prick (percutaneous) or intradermal tests. Patients must avoid antihistamines for 3 to 10 days prior to testing to prevent false negatives.