Regional Anesthesia and Nerve Blocks Flashcards

The interscalene brachial plexus block is the preferred regional technique for surgery on which anatomical region?

Answer: Shoulder and proximal humerus

The interscalene block targets the C5-C7 roots of the brachial plexus, providing excellent anesthesia for shoulder and proximal humerus surgery where these roots are dominant.

Which complication occurs in nearly 100% of interscalene brachial plexus blocks?

Answer: Ipsilateral phrenic nerve palsy

The phrenic nerve (C3-C5) runs directly adjacent to the brachial plexus at the interscalene level and is invariably blocked, causing ipsilateral hemidiaphragm paresis—a critical consideration in patients with contralateral phrenic nerve palsy or severe pulmonary disease.

The femoral nerve block provides sensory coverage primarily to which area?

Answer: Anterior and medial thigh, knee, and medial leg

The femoral nerve (L2-L4) innervates the anterior and medial thigh, the knee joint, and the medial aspect of the leg and foot via the saphenous nerve, making it highly useful for knee surgery analgesia.

During an axillary brachial plexus block, which nerve most commonly requires a separate injection because it exits the neurovascular sheath proximal to the standard injection site?

Answer: Musculocutaneous nerve

The musculocutaneous nerve typically exits the brachial plexus sheath high in the axilla and enters the coracobrachialis muscle before the standard axillary injection site, requiring a separate injection into that muscle for complete block.

Which combination of nerve blocks provides comprehensive analgesia for an above-knee amputation?

Answer: Femoral and sciatic nerve blocks

Above-knee amputation requires coverage of both the anterior thigh (femoral nerve) and the posterior thigh through the sciatic nerve distribution, necessitating a combined femoral and sciatic nerve block.

The transversus abdominis plane (TAP) block primarily targets which type of pain following abdominal surgery?

Answer: Somatic pain from the anterior abdominal wall

The TAP block deposits local anesthetic between the internal oblique and transversus abdominis muscles, blocking thoracolumbar nerves (T10-L1) that supply the anterior abdominal wall, providing somatic incisional analgesia.

Which local anesthetic is preferred for continuous peripheral nerve block infusions due to its long duration, favorable sensory-motor differential, and lower cardiotoxicity?

Answer: Ropivacaine

Ropivacaine is the S-enantiomer with long duration of action, produces preferential sensory block over motor block at lower concentrations, and has lower cardiac and CNS toxicity compared to racemic bupivacaine.