Diagnostic testing

Diagnostic Testing Overview

  • Definition: Diagnostic testing is used to examine various aspects of the body, assess indicators of health, and assist primary care providers in determining treatment.

  • Role of Nurses: Nurses must perform tests, understand results, and communicate abnormal findings to providers.

Important Considerations

  • Sample Types:

    • Determine the type of sample needed and how it will be collected.

  • Patient Preparation:

    • NPO (nothing by mouth): Clients may need to fast before certain tests.

  • Administration of Contrast Dye:

    • Assess if contrast dye will be used in the testing process.

  • Medication Instructions:

    • Clarify which medications should be given or withheld prior to testing.

  • Test Duration:

    • Understand how long the test will take.

  • Consent Requirements:

    • Check if a consent form is necessary.

Preparing for Diagnostic Testing

  • Client Instructions:

    • Explain the procedure and purpose of the test to clients and families.

    • Provide information about activity restrictions related to the test.

    • Discuss the diagnostic equipment involved.

    • Inform about the time frame for result availability and emphasize that only the doctor can give results.

    • Encourage clients to ask questions to clarify information and reduce anxiety.

Complete Blood Count (CBC)

  • Key Components:

    • Hemoglobin (Hgb): M: 14-18; F: 12-16

    • Hematocrit (Hct): M: 42-52; F: 37-47

    • Erythrocytes (RBC): M: 4.7-6.1; F: 4.2-5.4

    • Platelets: 150,000-400,000

    • Leukocyte Count: 5,000 – 10,000

    • Differential white blood cell count.

Basic Metabolic Panel (BMP)

  • Components:

    • BUN: 10-20

    • Creatinine: M 0.6-1.2; F 0.5-1.1

    • Potassium: 3.5-5

    • Sodium: 135-145

    • Calcium: 9-10.5

    • Chloride: 98-106

    • Glucose levels assessed.

Blood Glucose Monitoring

  • Normal Range: Glucose 70-110

  • Importance: Frequently monitored in diabetic patients.

  • Further Testing for Diabetes: Glycosylated Hemoglobin (Hgb A1C) evaluates blood sugar levels over 2-3 months.

Comprehensive Metabolic Panel (CMP)

  • Includes BMP Plus:

    • Liver enzymes

    • Protein levels

    • Albumin

    • Bilirubin

Capillary Blood Specimen Collection (Skill 34.1)

  • Collection Process:

    • Ensure the finger is warm to increase blood flow.

    • Wipe the site with an alcohol wipe and allow drying.

    • Wipe away the first drop of blood to avoid contamination.

    • Recommended site: side of the fingertip for adults and children over 2 years old.

Other Blood Specimen Exams

  • Drug Monitoring: To assess patient compliance and safe medication dosages.

  • Arterial Blood Gases: Evaluate patient oxygenation status and acid-base balance.

Urine Specimen Collection Techniques

  • Types:

    • Clean-voided: first morning void.

    • Clean-catch mid-stream technique: clean perineum, initiate stream, then capture the specimen.

    • Timed urine specimens: discard first void and save urine throughout the specified timeframe.

Reasons for Urine Testing

  • Indicators:

    • Specific gravity measures fluid status.

    • pH levels (normal pH = 6).

    • Presence of glucose, ketones, protein, and occult blood for various health assessments.

Urinary Diagnostics & Procedures

  • Imaging Tests:

    • KUB: visualize kidneys, ureters, bladder.

    • IV Pyelography: visualize structures with contrast medium injected intravenously.

    • Ultrasonography: noninvasive visualization of soft tissue organs.

Stool Specimen Collection

  • Reasons for Testing: Check for occult blood, dietary product analysis, presence of parasites, and microorganisms.

  • Collection Instructions: Use clean containers, avoid contamination with urine, and notify staff promptly for processing.

Stool Specimen Principles

  • Testing Methods:

    • Guaiac smear for blood detection (hemoccult test).

    • Steatorrhea indicates fat in stool, suggesting small intestine absorption issues.

    • Timeliness in sending specimens for analysis is critical.

Other Specimen Collections

  • Types:

    • Sputum: microbial identification in lungs.

    • Nasopharyngeal: virus detection.

    • Throat cultures: bacterial and viral identification.

    • Wound drainage: infection diagnosis.

Imaging Techniques

  • Types of Imaging:

    • X-ray, ultrasound, CT scans, MRI for soft tissues.

    • Nuclear imaging (e.g., PET scan) involves radioactive isotopes.

  • Mammograms: Recommended annually for low-risk women starting at age 45.

Cardiopulmonary Diagnostics

  • Key Tests:

    • Electrocardiography: records electrical activity (ECG).

    • Angiography: for viewing blood flow through vessels.

    • Echocardiogram: non-invasive ultrasound of heart structure.

GI Diagnostics & Procedures

  • Endoscopy Types:

    • Anoscopy, Proctoscopy, Colonoscopy, and more for examining the GI tract.

    • Barium swallow/enema for enhanced visualization of GI structures.

Aspirations & Biopsies

  • Collection Procedures:

    • Needle aspirations to remove fluid

    • Biopsies for tissue samples

    • Types include lumbar puncture, paracentesis, thoracentesis, among others.

Lumbar Puncture Procedure

  • Procedure involves inserting a needle into the subarachnoid space to collect cerebrospinal fluid, requiring sterile technique and specific positioning of the patient.

Safety Alerts

  • Importance: Timely communication of critical results is vital for patient care, as it impacts decisions and outcomes.

Nursing Diagnoses Related to Diagnostic Testing

  • Possible nursing diagnoses include:

    • Anxiety related to perceived threats from procedures.

    • Readiness to learn about tests and care required.

    • Risk for injury due to medications affecting sensations.