CRNI Pain Management and Analgesic Infusion Therapy 5 — Questions and Answers
Question 1: Which local anesthetic concentration is most appropriate for a patient receiving lumbar epidural analgesia where motor preservation is the priority?
- Bupivacaine 0.5% to ensure dense blockade
- Bupivacaine 0.0625–0.125% for differential sensory block (Correct answer)
- Lidocaine 2% for rapid onset
- Ropivacaine 1% for prolonged duration
Correct answer: Bupivacaine 0.0625–0.125% for differential sensory block
Low-concentration bupivacaine produces a differential block that reduces pain with minimal motor impairment, preserving ambulation.
Question 2: A patient receiving intrathecal ziconotide reports new-onset confusion, hallucinations, and dizziness. What is the most appropriate initial intervention?
- Administer naloxone to reverse CNS effects
- Reduce or discontinue ziconotide and notify the prescriber (Correct answer)
- Increase IV fluids to dilute the drug systemically
- Switch to a lower dose of intrathecal morphine
Correct answer: Reduce or discontinue ziconotide and notify the prescriber
CNS adverse effects (confusion, hallucinations, dizziness) are dose-limiting toxicities of ziconotide and require dose reduction or discontinuation.
Question 3: When teaching a patient to use PCA, which instruction is most important to prevent oversedation?
- Press the button as often as possible to stay ahead of pain
- Only the patient should press the button, not family members (Correct answer)
- Press the button before pain reaches a 7/10 level
- Use the button during sleep to maintain blood levels
Correct answer: Only the patient should press the button, not family members
Only the patient should activate PCA because the patient's level of consciousness serves as a built-in safety mechanism against overdose.
Question 4: A CRNI is calculating the lockout interval for a hydromorphone PCA. The onset of IV hydromorphone is approximately 5 minutes. Which lockout interval is most appropriate?
- 2 minutes to allow frequent dosing
- 5–10 minutes to allow drug effect before the next dose (Correct answer)
- 30 minutes to prevent rapid repeated dosing
- 60 minutes to match the drug's peak effect
Correct answer: 5–10 minutes to allow drug effect before the next dose
A 5–10 minute lockout allows enough time for hydromorphone to reach peak effect before the patient can request another dose, balancing efficacy and safety.
Question 5: Which of the following is a contraindication to neuraxial analgesia?
- Patient age greater than 70 years
- INR of 2.8 in a patient on warfarin (Correct answer)
- Mild chronic obstructive pulmonary disease
- History of previous uncomplicated epidural
Correct answer: INR of 2.8 in a patient on warfarin
An INR ≥1.5 indicates coagulopathy, which is a contraindication to neuraxial block due to the risk of epidural hematoma.
Question 6: A patient on chronic buprenorphine therapy is admitted for postoperative pain management. Which approach best addresses their analgesic needs?
- Discontinue buprenorphine and use full agonist opioids alone
- Continue buprenorphine and add non-opioid multimodal analgesics plus possible supplemental opioids (Correct answer)
- Switch to methadone at an equianalgesic dose
- Avoid all opioids due to opioid-receptor saturation
Correct answer: Continue buprenorphine and add non-opioid multimodal analgesics plus possible supplemental opioids
Continuing buprenorphine prevents withdrawal while multimodal agents and high-affinity full agonists (e.g., hydromorphone) can provide additional analgesia for acute pain.
Question 7: Which parameter should a CRNI monitor most closely in a patient receiving epidural fentanyl, compared to epidural morphine?
- Delayed respiratory depression occurring 6–24 hours later
- Early respiratory depression within 30–60 minutes of administration (Correct answer)
- Urinary retention persisting beyond 48 hours
- Pruritus beginning 12 hours after the dose
Correct answer: Early respiratory depression within 30–60 minutes of administration
Fentanyl is lipophilic, causing early respiratory depression within 30–60 minutes rather than the delayed (6–24 hour) pattern seen with hydrophilic morphine.
CRNI Pain Management and Analgesic Infusion Therapy 5
Which local anesthetic concentration is most appropriate for a patient receiving lumbar epidural analgesia where motor preservation is the priority?