CAA Regional & Neuraxial Anesthesia Flashcards

At which vertebral interspace is spinal anesthesia most commonly performed in adults to avoid injury to the spinal cord?

Answer: L2–L3 or L3–L4

The spinal cord ends at approximately L1–L2 in adults; intrathecal injection is performed below this level (L2–L3 or L3–L4) to avoid direct cord injury.

Which baricity of local anesthetic is used for spinal anesthesia when the patient is placed in the sitting position for a 'saddle block'?

Answer: Hyperbaric

Hyperbaric local anesthetic is heavier than CSF and sinks with gravity; when the patient remains seated, it concentrates in the sacral (saddle) region.

Post-dural puncture headache (PDPH) is caused by:

Answer: Leakage of CSF through the dural puncture site, causing intracranial hypotension

CSF leaking through the dural hole lowers intracranial pressure, causing traction on pain-sensitive intracranial structures when the patient is upright.

The DEFINITIVE treatment for a severe post-dural puncture headache is:

Answer: Epidural blood patch

An epidural blood patch—injecting 15–20 mL of the patient's autologous blood into the epidural space—seals the dural hole and provides rapid, durable relief.

Total spinal anesthesia is a life-threatening complication characterized by:

Answer: High cephalad spread of intrathecal drug causing apnea, hypotension, and unconsciousness

Excessive cephalad spread of intrathecal local anesthetic blocks cervical spinal roots and the brainstem, causing respiratory arrest, profound hypotension, and loss of consciousness.

Which patient position during a spinal anesthetic MOST effectively limits cephalad spread of a hyperbaric local anesthetic solution?

Answer: Reverse Trendelenburg (head-up)

Reverse Trendelenburg keeps the head higher than the injection site so the hyperbaric (gravity-dependent) solution pools in the lumbar region rather than spreading cephalad.