ABA ABA Regional & Neuraxial Anesthesia 1 — Questions and Answers
Question 1: A post-dural puncture headache (PDPH) is BEST characterized by which feature?
- Occipital pain unaffected by position
- Frontal/occipital pain worsened upright and relieved supine (Correct answer)
- Unilateral throbbing pain with photophobia only
- Constant headache worsened by lying flat
Correct answer: Frontal/occipital pain worsened upright and relieved supine
PDPH is caused by CSF leak through the dural puncture site, causing traction on pain-sensitive intracranial structures when upright; lying flat relieves the traction.
Question 2: The epidural blood patch is considered the DEFINITIVE treatment for PDPH. Its mechanism of action is:
- Increasing CSF production
- Sealing the dural leak with a clot and transiently increasing epidural pressure (Correct answer)
- Diluting the CSF to reduce meningeal inflammation
- Reducing subarachnoid pressure through venous compression
Correct answer: Sealing the dural leak with a clot and transiently increasing epidural pressure
15–20 mL of autologous blood is injected epidurally; it clots over the dural tear and transiently increases epidural pressure, restoring normal CSF dynamics.
Question 3: During spinal anesthesia, a 'total spinal' occurs. The MOST immediate life-threatening consequence is:
- Urinary retention
- Apnea and cardiovascular collapse from high cervical blockade (Correct answer)
- Nausea and vomiting from vagal activation
- Shivering from hypothermia
Correct answer: Apnea and cardiovascular collapse from high cervical blockade
High spinal block paralyzes intercostal and phrenic nerves and blocks cardiac accelerator fibers (T1-T4), causing apnea, bradycardia, and profound hypotension.
Question 4: Which factor INCREASES the spread of spinal anesthesia?
- Using hypobaric solution in Trendelenburg position
- Using hyperbaric solution in Trendelenburg position (Correct answer)
- Increased patient height
- Decreased baricity of the solution
Correct answer: Using hyperbaric solution in Trendelenburg position
Hyperbaric solutions are denser than CSF and flow with gravity; in Trendelenburg (head-down), hyperbaric local anesthetic migrates cephalad, increasing spread.
Question 5: The recommended interspace for spinal anesthesia in adults to avoid spinal cord injury is:
- L1-L2
- T12-L1
- L3-L4 or L4-L5 (Correct answer)
- L2-L3 only
Correct answer: L3-L4 or L4-L5
The spinal cord ends at L1-L2 in adults (conus medullaris); L3-L4 or L4-L5 interspaces are below the cord terminus, eliminating direct cord injury risk.
Question 6: Local anesthetic systemic toxicity (LAST) involving the CNS typically presents in which ORDER?
- Seizures → tinnitus/circumoral numbness → cardiovascular collapse
- Cardiovascular collapse → tinnitus → seizures
- Tinnitus/circumoral numbness → seizures → cardiovascular collapse (Correct answer)
- Unconsciousness → tinnitus → seizures
Correct answer: Tinnitus/circumoral numbness → seizures → cardiovascular collapse
CNS excitation (tinnitus, perioral numbness, visual disturbance) precedes seizures, which precede CNS depression and eventual cardiovascular collapse as plasma levels rise.
ABA ABA Regional & Neuraxial Anesthesia 1
A post-dural puncture headache (PDPH) is BEST characterized by which feature?