Key Takeaways
- Hold metformin 48 hours before and after contrast dye procedures
- Assess pedal pulses every 15 minutes initially after cardiac catheterization
- Pacemakers are generally contraindicated for MRI
- Position patient on right side after liver biopsy to apply pressure to the site
- NPO until gag reflex returns after procedures involving throat sedation/anesthesia
Last updated: January 2026
Diagnostic Tests and Procedures
LPN/VNs assist with various diagnostic tests and procedures, providing patient education, preparation, and post-procedure monitoring. Understanding these procedures ensures patient safety and comfort.
Imaging Studies
| Study | Preparation | Nursing Considerations |
|---|---|---|
| X-ray | Remove metal objects, jewelry | Pregnancy status, lead shielding |
| CT Scan | NPO if contrast used, assess allergies | Contrast allergy precautions, hydration |
| MRI | No metal objects, assess for implants | Contraindicated with pacemakers, some implants; claustrophobia management |
| Ultrasound | May require full bladder (pelvic) or NPO (abdominal) | Non-invasive, no radiation |
| Nuclear Medicine | Varies by study; may require NPO | Explain radioactive tracer use; safe for others after |
Contrast Media Considerations:
- Assess for allergies (especially iodine, shellfish for iodinated contrast)
- Check kidney function (BUN, creatinine) before contrast
- Hold metformin 48 hours before and after contrast (lactic acidosis risk)
- Encourage fluids after procedure to flush contrast
- Monitor for delayed reactions (rash, itching, nausea)
Cardiac Diagnostic Tests
| Test | Purpose | Patient Preparation |
|---|---|---|
| ECG/EKG (12-lead) | Record heart electrical activity | Remove upper clothing, lie still, no movement during test |
| Echocardiogram | Ultrasound of heart structure/function | No special prep for transthoracic; NPO for TEE |
| Stress Test | Evaluate cardiac response to exercise | NPO 4 hours, wear comfortable shoes, hold caffeine/beta blockers |
| Cardiac Catheterization | Visualize coronary arteries | NPO, assess allergies, mark pedal pulses, consent |
| Holter Monitor | 24-48 hour continuous ECG recording | Keep diary of activities and symptoms |
Post-Cardiac Catheterization Care:
- Monitor insertion site for bleeding, hematoma
- Assess pulses distal to insertion site every 15 minutes initially
- Check for numbness, tingling, color changes in extremity
- Maintain bed rest per protocol (usually 2-6 hours for femoral approach)
- Encourage fluids to flush contrast
- Monitor for chest pain, arrhythmias
Gastrointestinal Procedures
| Procedure | Preparation | Post-Procedure Care |
|---|---|---|
| Upper GI Series (Barium Swallow) | NPO 8-12 hours, no smoking | Increase fluids, laxatives for barium elimination |
| EGD (Esophagogastroduodenoscopy) | NPO 6-8 hours, consent | NPO until gag reflex returns, monitor for bleeding |
| Colonoscopy | Clear liquid diet, bowel prep, NPO | Monitor VS, assess for bleeding, diet as tolerated |
| ERCP | NPO, consent, labs | NPO until gag reflex returns, watch for pancreatitis |
| Paracentesis | Empty bladder, obtain weight | Monitor VS, measure abdominal girth, document output |
Bowel Preparation for Colonoscopy:
- Clear liquid diet day before procedure
- Drink prescribed laxative solution (GoLYTELY, MiraLAX)
- Stay near bathroom; expect frequent watery stools
- Goal: Clear, yellow liquid output
- NPO after midnight
Respiratory Diagnostic Tests
| Test | Purpose | Nursing Considerations |
|---|---|---|
| Chest X-ray | Visualize lungs, heart | Remove jewelry, assess pregnancy |
| Pulmonary Function Tests (PFTs) | Measure lung capacity, airflow | Hold bronchodilators if ordered; teach breathing technique |
| Bronchoscopy | Direct visualization of airways | NPO 6-8 hours, consent, NPO until gag returns |
| Thoracentesis | Remove pleural fluid | Position leaning forward, monitor for pneumothorax |
Post-Bronchoscopy Care:
- NPO until gag reflex returns (usually 2 hours)
- Monitor for respiratory distress
- Expect blood-tinged sputum initially
- Semi-Fowler's position
- Apply ice to throat for comfort
Lumbar Puncture (Spinal Tap)
Purpose: Obtain CSF for analysis (meningitis, MS, bleeding)
Preparation:
- Explain procedure; obtain consent
- Position patient in fetal position (side-lying with knees to chest) or sitting, leaning forward
- Maintain sterile field
Post-Procedure Care:
- Keep patient flat for 4-8 hours (prevents spinal headache)
- Encourage oral fluids
- Monitor for headache, neurological changes
- Check puncture site for leakage, redness
- Monitor vital signs
Biopsy Procedures
| Type | Purpose | Post-Procedure Monitoring |
|---|---|---|
| Skin Biopsy | Diagnose skin conditions | Bleeding, infection signs |
| Bone Marrow Biopsy | Evaluate blood disorders | Bleeding at site, pain management |
| Liver Biopsy | Evaluate liver disease | Position on right side, VS q15min, bleeding |
| Renal Biopsy | Evaluate kidney disease | Bed rest, VS q15min, hematuria |
Post-Liver Biopsy:
- Position patient on right side for 2-4 hours (applies pressure to site)
- Monitor VS every 15 minutes × 4, then every 30 minutes × 4
- Assess for bleeding: abdominal pain, hypotension, tachycardia
- Bed rest for 6-8 hours
Patient Teaching for Diagnostic Tests
Key Teaching Points:
- Purpose of the test and what to expect
- Any preparation required (NPO, bowel prep, medications to hold)
- Duration of the procedure
- Sensations they may experience
- Post-procedure activity restrictions
- When and how results will be communicated
- Symptoms to report after the procedure
Test Your Knowledge
After a cardiac catheterization via the femoral artery, how often should the LPN/VN initially assess the pedal pulses?
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D
Test Your Knowledge
A patient is scheduled for an MRI. Which condition would be a contraindication to this procedure?
A
B
C
D
Test Your Knowledge
Following a liver biopsy, in which position should the LPN/VN place the patient?
A
B
C
D