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Which local anesthetic is contraindicated for use in intravenous regional anesthesia (IVRA)?
Bupivacaine (due to cardiotoxic profile)
What regional technique is best avoided in patients receiving positive-pressure ventilation?
Interpleural block (due to risk of pneumothorax)
What are the advantages of periorbital or peribulbar blocks?
Less risk of globe penetration, optic nerve injury and artery injury, less pain on injection
What are the disadvantages of periorbital or peribulbar blocks?
Slower onset, larger anesthetic volume, increased likelihood of ecchymosis
Where does interpleural injection provide analgesia?
The chest wall and upper abdomen
Rate sites of systemic LA absorption from greatest to least
1.  IV
2.  Tracheal
3.  Intercostal
4.  Caudal
5.  Epidural
6.  Brachial plexus
7.  Sciatic-Femoral
8.  Subcutaneous        
What is the greatest immediate risk of nerve block?
Systemic toxicity from inadvertent intravascular injection.  Delayed toxicity can also follow injection.
How is good surgical anesthesia achieved with nerve blocks?
When LA is injected in close proximity to the nerve or nerves to be blocked
What does a perineural injection produce?
A brief accentuation of the parasthesia
What does an intraneural injection produce?
An intense, searing pain that serves as a warning to immediately terminate the injection and reposition the needle
How is surgical anesthesia of the extremity and shoulder obtained?
Through blockade of the brachial plexus (C5-T1) or any of its terminal branches
What procedures are most optimally controlled with an interscalene block?
Shoulder, arm and forearm
Where is interscalene block most intense?  Least intense?
Most:  C5-C7
Least:  C8-T1
When is the axillary approach to the brachial plexus most useful?
Procedures from the elbow to the hand
Where is an axillary block most intense?
C7-T1 (ulnar nerve)
What are infraclavicular blocks good for?
They are homogeneous:  hand, forearm, elbow, and upper arm; an indwelling catheter may be placed
What is Bier block used for?
Short surgical procedures
What is femoral nerve block used for?
Thigh and knee procedures (skin grafting, knee arthroscopy, and patellar surgery), or as an adjunct to distal procedures (blocks saphenous distribution, medial)
What advantages does a fascia iliaca block offer?
No nerve stimulator required, it can be performed quickly, it is not very stimulating, patients do not often require sedation.  It is useful for hip, thigh, and knee surgeries.
What is sciatic nerve block useful for?
Hip, knee, or distal LE surgery.
What is a popliteal nerve block useful for?
Foot and ankle surgery, can provide complete anesthesia below the knee when combined with saphenous block
What are paravertebral nerve blocks used for?
Postoperative analgesia for mastectomy, inguinal hernia repair, and several chest and body wall procedures
A motor response at what mA indicates that the needle is in the appropriate location to inject LA?
0.5 mA
What are the contraindications to peripheral nerve blocks?
Uncooperative patient
Bleeding diathesis
Infection
LA toxicity (ie, requirement of bilat axillary blocks)
Peripheral neuropathy (Ipsilateral interscalene block contraindicated in contralateral phrenic nerve palsy)
What are techniques to reduce immediate toxicity?
Syringe aspiration, use of a test dose (containing 1:200,000 or 1:400,000 epinephrine).  Intermittent (5 mL) doses.

Increase in HR 20% over baseline is indicative of intravascular injection.
What are common LAs used for peripheral nerve blocks?
Lidocaine 1.5-2%, Mepivacaine 2%, Bupivacaine 0.5%, Levobupivacaine 0.5%, or Ropivacaine 0.5%.

More dilute solutions are used for postoperative analgesia.
Name an example of a field block
Superficial cervical plexus block, intercostobrachial and medial brachial cutaneous blocks (to compliment axillary), ankle supplementation
What may help reduce systemic absorption and toxicity?
Dilution and addition of epinephrine
From superior to inferior, what is the order of the intercostal blood vessels and nerve on the undersurface of the inferior border of each rib?
VAN (Vein, artery, nerve)
From lateral to medial how are vessels, the nerve, and other structures identified for femoral nerve block?
NAVEL (Nerve, artery, vein, empty space, lymphatics)
What type of needle is used for peripheral nerve blocks?
Blunt bevel (B-bevel)
What is the range of current outputs for nerve stimulators?
0.1-6.0 mA
In descending order, how is the brachial plexus divided?
Roots, trunks, divisions, cords, branches
What innervates the anterior shoulder?
C1-C4
How is the anterior shoulder blocked?
A field block at the posterior border of the sternocleidomastoid muscle
Which nerve roots make up the medial brachial cutaneous nerve? The intercostobrachial nerve?  Why must they be blocked?
C8-T1; T2

To prevent pain from an arm tourniquet
What are the three trunks of the brachial plexus?
1.  Superior (C5-C6)
2.  Middle (C7)
3.  Inferior (C8-T1) 
What are the three cords of the brachial plexus?  How are they named?
1.  Lateral
2.  Medial
3.  Posterior

They are named based on their position about the axillary artery.
What does the lateral cord of the brachial plexus become?
MEDIAN nerve, MUSCULOCUTANEOUS nerve
What does the medial cord of the brachial plexus become?
MEDIAN and ULNAR nerves
What does the posterior cord of the brachial plexus become?
AXILLARY and RADIAL nerves
What does the interscalene approach fail to block?
The ulnar nerve
Which block most effectively blocks the ulnar nerve?
Axillary
Which level of the brachial plexus is blocked with an interscalene approach?
Trunks (the level of the cricoid cartilage)
How can interscalene anatomy be better visualized?
Have the patient lift and turn the head against resistance
What paresthesia should be ellicited when performing an interscalene block?
Movement of the arm, wrist, or hand, deltoid or pectoralis.  Phrenic nerve activity is too "anterior", trapezius muscle activity is too "posterior"
What volume of LA is used for an interscalene block?
30-40 mL
How does phrenic nerve block present?
Respiratory failure, Horner's syndrome (miosis, ptosis, anhidrosis), dyspnea, and hoarseness
Which artery is in proximity to interscalene space?  What can result from intravascular injection of LA?
Vertebral artery; seizure (with as little as 1-3 mL)
What portion of the brachial plexus is blocked with a supraclavicular (subclavian) approach?
Trunks
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