ABA Regional & Neuraxial Anesthesia Flashcards

Epidural analgesia for labor uses which nerve roots as the PRIMARY target for pain relief during the first stage of labor?

Answer: T10-L1

First-stage labor pain from uterine contractions and cervical dilation is transmitted via T10-L1 visceral afferents; second-stage pain also involves S2-S4.

Which complication is associated with unintentional intravascular injection during an interscalene brachial plexus block?

Answer: Vertebral artery injection causing seizures

The interscalene block is performed adjacent to the vertebral artery; even 1 mL of local anesthetic injected intra-arterially can cause immediate seizures.

Continuous epidural infusion for postoperative analgesia typically combines a local anesthetic with an opioid. The PRIMARY benefit of this combination is:

Answer: Reducing total opioid requirements with synergistic analgesia at lower individual drug doses

Combining low-dose local anesthetic with epidural opioid exploits synergy at spinal opioid receptors, achieving better analgesia at lower doses of each drug.

Horner syndrome (ptosis, miosis, anhidrosis) after a regional block indicates blockade of the:

Answer: Cervical sympathetic chain (stellate ganglion)

Horner syndrome results from blockade of the cervical sympathetic trunk or stellate ganglion, commonly seen after interscalene or stellate ganglion blocks.

An absolute contraindication to neuraxial anesthesia is:

Answer: Patient refusal

Patient refusal is an absolute contraindication to any anesthetic technique; informed consent is a fundamental ethical and legal requirement.

The safest minimum time interval to perform neuraxial block after the LAST dose of low-molecular-weight heparin (LMWH) prophylaxis is:

Answer: 12 hours

ASRA guidelines recommend waiting at least 12 hours after prophylactic LMWH (e.g., enoxaparin 40 mg daily) before neuraxial procedures to minimize epidural hematoma risk.