BCA Postoperative Pain Management 3 — Questions and Answers
Question 1: What is the ceiling effect of buprenorphine most clinically relevant to in postoperative analgesia?
- Analgesic effect plateaus at moderate doses
- Respiratory depression plateaus at higher doses than analgesia (Correct answer)
- Nausea increases linearly with dose
- Sedation increases proportionally with analgesia
Correct answer: Respiratory depression plateaus at higher doses than analgesia
Buprenorphine's partial agonism means respiratory depression reaches a ceiling at subanesthetic doses, making it safer than full agonists in overdose.
Question 2: Which parameter best guides dose titration of patient-controlled analgesia (PCA) when a patient reports inadequate pain relief between PCA doses?
- Increase lockout interval
- Increase the demand dose (Correct answer)
- Add a continuous basal infusion
- Decrease the demand dose and shorten lockout
Correct answer: Increase the demand dose
Increasing the demand dose delivers more opioid per activation when baseline pain is undertreated between doses.
Question 3: A postoperative patient develops pruritus after intrathecal morphine. What is the first-line treatment?
- Diphenhydramine 25 mg IV
- Nalbuphine 5 mg IV (Correct answer)
- Hydroxyzine 25 mg PO
- Ondansetron 4 mg IV
Correct answer: Nalbuphine 5 mg IV
Nalbuphine, a mixed agonist-antagonist, reverses neuraxial opioid-induced pruritus without fully reversing analgesia.
Question 4: Celecoxib differs from ketorolac in the postoperative setting primarily because celecoxib:
- Has a faster onset of analgesic action
- Does not impair platelet aggregation (Correct answer)
- Can be given intravenously
- Has greater anti-inflammatory potency
Correct answer: Does not impair platelet aggregation
Celecoxib selectively inhibits COX-2 and does not inhibit COX-1-mediated thromboxane A2 production, preserving platelet function.
Question 5: Which nerve block is the most appropriate single regional technique for total knee arthroplasty analgesia that avoids motor blockade of the quadriceps?
- Femoral nerve block
- Adductor canal block (Correct answer)
- Sciatic nerve block at the popliteal fossa
- Lumbar plexus block
Correct answer: Adductor canal block
The adductor canal block targets the saphenous nerve (sensory) within the canal, sparing the motor branches to the quadriceps that exit proximally.
Question 6: Opioid-induced hyperalgesia (OIH) is best distinguished from opioid tolerance by which clinical finding?
- Increased pain scores despite dose escalation
- Pain that spreads beyond the original surgical site (Correct answer)
- Rapid development within 24 hours of opioid initiation
- Relief with dose reduction or opioid rotation
Correct answer: Pain that spreads beyond the original surgical site
OIH characteristically produces diffuse, poorly localized pain extending beyond the original painful area, unlike tolerance which causes diminished effect at the same dose.
Question 7: When performing a transversus abdominis plane (TAP) block for lower abdominal surgery, which nerve roots are targeted?
- T4–T8
- T10–L1 (Correct answer)
- L1–L3
- T7–T10
Correct answer: T10–L1
The TAP block targets the T10–L1 anterior cutaneous branches as they travel through the neurofascial plane between the internal oblique and transversus abdominis muscles.
BCA Postoperative Pain Management 3
What is the ceiling effect of buprenorphine most clinically relevant to in postoperative analgesia?