EMG Risk Management & Mitigation 2 — Questions and Answers
Question 1: A patient with a pacemaker is referred for EMG. What is the primary risk management concern?
- Electromagnetic interference potentially affecting pacemaker function (Correct answer)
- Increased pain during needle insertion
- Reduced nerve conduction velocity readings
- Higher risk of muscle hematoma
Correct answer: Electromagnetic interference potentially affecting pacemaker function
EMG electrical stimulation can cause electromagnetic interference with pacemakers, requiring coordination with the patient's cardiologist and use of bipolar electrodes when necessary.
Question 2: Which action best mitigates the risk of cross-contamination between patients during EMG procedures?
- Using the same needle with alcohol wipe between patients
- Using single-use disposable needle electrodes for each patient (Correct answer)
- Sterilizing needles in an autoclave between uses
- Soaking needles in glutaraldehyde for 10 minutes
Correct answer: Using single-use disposable needle electrodes for each patient
Single-use disposable needle electrodes eliminate the risk of bloodborne pathogen transmission between patients and are the standard of care in EMG practice.
Question 3: During an EMG, a patient suddenly reports dizziness and appears pale. What is the most likely cause and appropriate response?
- Muscle cramp — apply heat and continue
- Vasovagal syncope — recline patient, elevate legs, monitor vitals (Correct answer)
- Allergic reaction — administer epinephrine immediately
- Electrical shock — disconnect all equipment
Correct answer: Vasovagal syncope — recline patient, elevate legs, monitor vitals
Vasovagal syncope is a common reaction to needle procedures; placing the patient supine and elevating the legs restores cerebral perfusion.
Question 4: What is the recommended waiting period before performing EMG on a patient who received thrombolytic therapy?
- No waiting period required
- At least 24 hours
- At least 72 hours
- At least 10 days (Correct answer)
Correct answer: At least 10 days
Thrombolytic therapy significantly increases bleeding risk, and most guidelines recommend waiting at least 10 days before performing needle EMG to reduce hematoma risk.
Question 5: A patient is found to have INR of 4.5 on the day of their EMG. Which muscle group poses the GREATEST bleeding risk if needle examination is performed?
- Tibialis anterior
- First dorsal interosseous
- Paraspinal muscles (Correct answer)
- Deltoid
Correct answer: Paraspinal muscles
Paraspinal muscles are located near major vascular structures and deep compartments, making hematoma formation in this region particularly dangerous in anticoagulated patients.
Question 6: What is the purpose of verifying electrode impedance before recording nerve conduction studies?
- To ensure adequate current flows through the nerve
- To minimize signal artifact and ensure recording quality (Correct answer)
- To calibrate the stimulator output intensity
- To confirm the patient is properly grounded
Correct answer: To minimize signal artifact and ensure recording quality
High impedance between recording electrodes and skin increases noise artifact, degrading signal quality and potentially leading to misinterpretation of waveforms.
Question 7: Which documentation element is most critical for medicolegal risk management after an adverse event during EMG?
- The patient's insurance information
- Accurate, contemporaneous record of the event, interventions, and patient outcome (Correct answer)
- A signed waiver from the patient
- The cost of the procedure
Correct answer: Accurate, contemporaneous record of the event, interventions, and patient outcome
A timely and accurate record of what occurred, what was done in response, and the patient's condition is the foundation of medicolegal protection.
EMG Risk Management & Mitigation 2
A patient with a pacemaker is referred for EMG.
What is the primary risk management concern?