UNIT 5 Diagnostic testing

Diagnostic Testing for Patients:

Introduction to Diagnostic Testing

Diagnostic testing plays a crucial role in identifying diseases, monitoring patient conditions, and planning appropriate treatment strategies. Nurses are essential in the diagnostic process, ensuring accurate test preparation, patient education, and proper specimen collection while maintaining ethical and safety standards.

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1. Role of Nurses in Diagnostic Testing

Nurses play a key role in the diagnostic testing process by:

1. Assessing the Patient – Evaluating the need for diagnostic tests based on signs and symptoms.
2. Educating the Patient – Providing information on the purpose, procedure, risks, and necessary preparations for the test.
3. Ensuring Safety – Preventing infections, maintaining patient dignity, and ensuring proper handling of specimens.
4. Monitoring the Patient – Observing for adverse reactions during or after the procedure.
5. Assisting with Specimen Collection – Drawing blood, collecting urine, stool, sputum, or swabs for laboratory analysis.
6. Interpreting and Communicating Results – Reporting critical values to the physician promptly.
7. Documentation – Recording the test performed, patient response, and significant findings in the nursing records.

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2. Types of Diagnostic Testing

A. Laboratory Tests

These tests analyze biological samples to detect abnormalities.

1. Hematology Tests
   • Complete Blood Count (CBC) – Evaluates RBC, WBC, platelets, hemoglobin, and hematocrit.
   • Coagulation Studies (PT, INR, APTT) – Assess blood clotting abilities.
2. Biochemical Tests
   • Blood Glucose (FBS, PPBS, HbA1c) – Monitors diabetes.
   • Liver Function Test (LFT) – Includes ALT, AST, bilirubin, albumin, and alkaline phosphatase.
   • Kidney Function Test (KFT) – Includes serum creatinine, BUN, and electrolytes.
   • Lipid Profile – Assesses cholesterol levels.
3. Microbiological Tests
   • Blood Culture – Detects systemic infections.
   • Sputum Culture – Identifies respiratory infections.
   • Urine Culture – Diagnoses urinary tract infections.
4. Immunological and Serological Tests
   • ELISA, Western Blot – Used for HIV/AIDS detection.
   • Widal Test – Identifies typhoid fever.
5. Urinalysis
   • pH, protein, glucose, ketones, RBCs, WBCs.
6. Stool Examination
   • Occult Blood Test – Detects hidden bleeding in the GI tract.
   • Parasite and Ova Test – Identifies intestinal infections.

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B. Radiological and Imaging Tests

These tests use imaging technology for diagnosing internal conditions.

1. X-ray
   • Used to detect fractures, lung infections, and abdominal abnormalities.
   • Nursing Responsibility: Remove metal objects, ensure pregnancy is ruled out.
2. Ultrasound (USG)
   • Used for obstetric, abdominal, and cardiac evaluations.
   • Nursing Responsibility: Ensure a full bladder for pelvic USG.
3. Computed Tomography (CT Scan)
   • Provides detailed cross-sectional imaging of organs.
   • Nursing Responsibility: Check for contrast dye allergies, ensure hydration.
4. Magnetic Resonance Imaging (MRI)
   • Produces detailed images of soft tissues, brain, and spine.
   • Nursing Responsibility: Remove metal objects, assess for claustrophobia.
5. Echocardiography
   • Assesses heart function using ultrasound waves.
   • Nursing Responsibility: Explain the procedure and ensure patient relaxation.
6. Endoscopy & Colonoscopy
   • Used for GI tract evaluation.
   • Nursing Responsibility: Ensure fasting, administer sedation if required.

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C. Electrodiagnostic Tests

These tests measure electrical activity in the body.

1. Electrocardiogram (ECG/EKG)
   • Records heart electrical activity.
   • Nursing Responsibility: Ensure proper electrode placement.
2. Electroencephalogram (EEG)
   • Assesses brain electrical activity in epilepsy or brain disorders.
   • Nursing Responsibility: Ensure a clean, oil-free scalp.
3. Nerve Conduction Studies (NCS)
   • Evaluates nerve damage or muscle disorders.

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D. Pulmonary Function Tests (PFTs)

• Assesses lung function and capacity.
• Nursing Responsibility: Instruct the patient to avoid smoking before the test.

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E. Genetic and Molecular Testing

1. Karyotyping – Identifies chromosomal abnormalities.
2. PCR (Polymerase Chain Reaction) – Used for infectious disease detection (e.g., COVID-19, TB).

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3. Nursing Responsibilities in Diagnostic Testing

A. Pre-Test Responsibilities

1. Patient Identification – Verify identity using two identifiers.
2. Patient Education – Explain the purpose, duration, and discomforts.
3. Preparation Instructions – Fasting, hydration, medication restrictions.
4. Consent – Obtain informed consent if required.
5. Psychological Support – Address anxiety and fears.
6. Safety Measures – Allergy checks for contrast media.

B. During-Test Responsibilities

1. Assisting the Physician – Handing over required instruments.
2. Monitoring the Patient – Checking for discomfort, adverse reactions.
3. Ensuring Specimen Integrity – Correct labeling and timely transport.

C. Post-Test Responsibilities

1. Observation for Reactions – Monitor for bleeding, dizziness, allergic responses.
2. Providing Comfort – Reassuring the patient.
3. Encouraging Hydration – Especially after contrast studies.
4. Reporting and Documentation – Record findings and communicate abnormal results.

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4. Ethical and Legal Considerations

• Confidentiality – Maintain patient privacy (HIPAA compliance).
• Informed Consent – Ensure patient understanding before invasive procedures.
• Safety Protocols – Follow universal precautions to prevent infections.
• Documentation – Accurate recording of test results and nursing actions.

Phases of Diagnostic Testing (Pre-Test, Intra-Test & Post-Test) in Common Investigations and Clinical Implications

Diagnostic testing is a crucial component of patient assessment, disease diagnosis, and treatment planning. The nursing process in diagnostic testing is divided into three key phases:

1. Pre-Test Phase – Preparing the patient for the procedure.
2. Intra-Test Phase – Assisting with the procedure and ensuring patient safety.
3. Post-Test Phase – Monitoring and managing patient recovery, interpreting results, and reporting findings.

Each phase is essential to ensure accuracy, safety, and quality in diagnostic testing. Below, we will discuss each phase in detail, along with common investigations and their clinical implications.

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1. Pre-Test Phase

Definition:

The pre-test phase involves preparing the patient for the diagnostic procedure, including physical preparation, psychological support, and obtaining necessary consents.

Nursing Responsibilities:

1. Patient Identification: Verify patient identity using at least two identifiers (e.g., name and hospital ID).
2. Patient Education:
   • Explain the purpose, process, and expected outcomes of the test.
   • Inform the patient about potential discomfort, risks, and precautions.
   • Provide instructions about fasting, medication restrictions, and hydration.
3. Obtaining Consent: Ensure the patient provides informed consent, especially for invasive procedures.
4. Physical Preparation:
   • Ensure the patient follows dietary restrictions (e.g., fasting for blood glucose, lipid profile, or ultrasound).
   • Adjust medications as per physician instructions (e.g., stopping anticoagulants before surgery).
5. Psychological Support:
   • Address patient fears and anxiety.
   • Provide reassurance and allow the patient to ask questions.
6. Infection Control:
   • Ensure aseptic techniques and proper hand hygiene.
   • Prepare sterile equipment for invasive procedures.
7. Specimen Collection Preparation:
   • Gather necessary supplies (e.g., blood collection tubes, urine containers, swabs).
   • Label samples accurately to prevent errors.
8. Assess Allergies:
   • Check for allergies, particularly to contrast media (iodine-based dyes) used in CT scans or angiography.

Pre-Test Clinical Implications for Common Investigations

Test	Pre-Test Preparation
Fasting Blood Sugar (FBS)	Ensure the patient fasts for 8-12 hours before the test.
Lipid Profile	Requires overnight fasting (10-12 hours) for accurate cholesterol levels.
Liver Function Test (LFT)	Avoid alcohol 24-48 hours before testing.
Kidney Function Test (KFT)	Check for dehydration before drawing blood.
X-ray (Chest/Abdomen)	Remove metallic objects; ensure the patient is not pregnant.
Ultrasound (Abdomen, Pelvis)	Full bladder required for pelvic ultrasound.
CT Scan (Contrast)	Check renal function before contrast administration; assess for contrast dye allergy.
MRI	Remove all metal objects (e.g., jewelry, pacemakers, cochlear implants).
ECG (Electrocardiogram)	Inform the patient to remain still; avoid caffeine 2 hours before the test.
Colonoscopy	Bowel preparation (laxatives/enemas) required 24 hours before.

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2. Intra-Test Phase

Definition:

The intra-test phase involves performing the test, ensuring patient safety, comfort, and accurate specimen collection.

Nursing Responsibilities:

1. Assisting the Physician/Technician:
   • Prepare necessary equipment and ensure a sterile field for invasive procedures.
   • Hand over instruments and monitor the test process.
2. Patient Positioning:
   • Ensure correct positioning for accurate test results (e.g., left lateral for ECG, lithotomy for Pap smear).
3. Monitoring the Patient:
   • Observe for complications such as allergic reactions (e.g., during contrast media administration in CT scans).
   • Monitor vital signs (BP, heart rate, oxygen saturation).
4. Ensuring Proper Specimen Collection:
   • Use correct techniques for blood, urine, stool, sputum, or tissue biopsies.
   • Label specimens properly and send them to the laboratory immediately.
5. Preventing Cross-Contamination:
   • Follow strict aseptic techniques in procedures like lumbar puncture and blood draws.
6. Ensuring Patient Comfort:
   • Provide emotional support and pain relief (local anesthesia if required).
7. Handling Medical Emergencies:
   • Be prepared to manage anaphylaxis, hypotension, or seizures due to test complications.

Intra-Test Clinical Implications for Common Investigations

Test	Nursing Considerations During the Test
Venipuncture for Blood Test	Ensure a tourniquet is not too tight; prevent hemolysis.
ECG	Keep the patient relaxed and still to avoid muscle interference.
X-ray	Ensure the patient follows breath-holding instructions.
Ultrasound	Instruct the patient to hold urine for pelvic ultrasound.
Endoscopy	Monitor for signs of discomfort; assist with sedation.
Colonoscopy	Observe for signs of perforation or bleeding.
CT Scan (Contrast)	Monitor for allergic reactions; ensure hydration.
MRI	Ensure the patient remains still for accurate imaging.
ABG (Arterial Blood Gas)	Apply pressure for 5-10 minutes to prevent bleeding.

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3. Post-Test Phase

Definition:

The post-test phase involves monitoring the patient for complications, providing post-procedure care, and ensuring accurate test documentation.

Nursing Responsibilities:

1. Monitor for Adverse Reactions:
   • Check for bleeding, dizziness, nausea, or allergic reactions.
   • Monitor vital signs, especially after invasive tests.
2. Encourage Hydration:
   • Post-contrast studies require increased fluid intake to flush out contrast media.
3. Provide Comfort Measures:
   • Offer a snack post-fasting tests (e.g., glucose tolerance test).
   • Encourage rest after lumbar puncture or biopsy procedures.
4. Observing for Complications:
   • Watch for signs of infection, hemorrhage, or delayed hypersensitivity reactions.
5. Documentation:
   • Record test results, patient responses, and any complications.
   • Report critical values immediately to the physician.
6. Patient Education on Results and Follow-Up:
   • Explain when and how the patient will receive results.
   • Provide follow-up instructions for abnormal findings.

Post-Test Clinical Implications for Common Investigations

Test	Post-Test Considerations
Blood Tests	Apply pressure to prevent bruising; monitor for dizziness.
X-ray	No specific precautions unless contrast was used.
CT Scan (Contrast)	Encourage fluids to flush out the dye; monitor kidney function.
MRI	No radiation exposure; ensure mental well-being in claustrophobic patients.
ECG	Inform the patient about further cardiac evaluation if abnormalities are detected.
Endoscopy	Monitor for throat discomfort and gag reflex return before oral intake.
Colonoscopy	Observe for abdominal pain or rectal bleeding.
Biopsy	Apply a pressure dressing; monitor for excessive bleeding.