NBCRNA Regional Anesthesia 2 — Questions and Answers
Question 1: The adductor canal block (subsartorial block) provides primarily what type of analgesia for knee surgery?
- Sensory analgesia with preserved quadriceps strength (Correct answer)
- Complete motor and sensory block of the lower leg
- Analgesia equivalent to femoral nerve block
- Motor block facilitating early physical therapy
Correct answer: Sensory analgesia with preserved quadriceps strength
The adductor canal contains the saphenous nerve and articular branches; blocking here provides medial knee and anterior thigh analgesia while largely preserving quadriceps motor function for early mobilization.
Question 2: LAST (Local Anesthetic Systemic Toxicity) initial CNS symptoms include which finding?
- Perioral numbness and metallic taste, progressing to seizures (Correct answer)
- Immediate cardiac arrest
- Hyperthermia and muscle rigidity
- Hypotension with normal CNS function
Correct answer: Perioral numbness and metallic taste, progressing to seizures
LAST typically presents with CNS excitation (perioral tingling, tinnitus, metallic taste, restlessness, seizures) before CNS depression and cardiovascular collapse.
Question 3: The treatment of choice for severe LAST with cardiovascular collapse is:
- Lipid emulsion therapy (Intralipid 20%) (Correct answer)
- High-dose epinephrine infusion
- Sodium bicarbonate bolus
- Defibrillation as primary intervention
Correct answer: Lipid emulsion therapy (Intralipid 20%)
Lipid emulsion therapy acts as a 'lipid sink,' sequestering the highly lipophilic local anesthetic from cardiac sodium channels and reversing cardiovascular toxicity.
Question 4: In ultrasound-guided nerve block, the in-plane technique means the needle is advanced:
- Parallel to the ultrasound beam so the entire shaft is visualized (Correct answer)
- Perpendicular to the ultrasound beam, showing only a cross-section
- At a 45-degree angle to the probe
- From the distal end toward the nerve
Correct answer: Parallel to the ultrasound beam so the entire shaft is visualized
In-plane needle advancement inserts the needle parallel to the ultrasound beam in the long axis, allowing visualization of the entire needle shaft and tip throughout the procedure.
Question 5: A transversus abdominis plane (TAP) block targets which anatomical space to provide abdominal wall analgesia?
- Fascial plane between internal oblique and transversus abdominis muscles (Correct answer)
- Epidural space at T10–L1 level
- Peritoneal cavity adjacent to bowel
- Subcutaneous tissue above the external oblique
Correct answer: Fascial plane between internal oblique and transversus abdominis muscles
The TAP block deposits local anesthetic in the neurofascial plane between the internal oblique and transversus abdominis, blocking T10–L1 intercostal nerves supplying the anterior abdominal wall.
Question 6: Horner syndrome (ptosis, miosis, anhidrosis) occurring after a brachial plexus block indicates what?
- Local anesthetic spread to the cervical sympathetic chain (Correct answer)
- Phrenic nerve palsy
- Vertebral artery injection
- Pneumothorax
Correct answer: Local anesthetic spread to the cervical sympathetic chain
Stellate ganglion block from local anesthetic spread interrupts the cervical sympathetic fibers, producing the classic ipsilateral Horner triad; it is benign and self-limiting.
NBCRNA Regional Anesthesia 2
The adductor canal block (subsartorial block) provides primarily what type of analgesia for knee surgery?