Chp. 53 Other Locoregional Techniques

Question 1

Can local and regional anesthetic techniques be used in combination with analgesics and GA?

Answer 1

• Local and regional anesthetic techniques often used in combination with analgesic/anesthetic drugs as part of a multimodal strategy to manage pain
• Preoperatively/postoperatively, moderate to severe pain usually easier to control if systemic analgesics used in combination with LAs

Question 2

When local and regional anesthetic techniques used in combination with GA, should they be used before or after surgery?

Answer 2

• Barrage of afferent input associated with surgical trauma alters nociceptive processing in dorsal horn of SC –> amplification, prolongation of postoperative pain
• Alteration in spinal processing of nociceptive input = central sensitization
• When local and regional anesthetic techniques used before surgery, unique ability to produce complete sensory blockade and prevent/preempt development of central sensitization

Question 3

Lidocaine

Answer 3

• Most versatile, most widely used LA
• Effective topically, used for local infiltration and IV regional anesthesia, peripheral/central (epidural, intrathecal) nerve block

Question 4

Bupivacaine

Answer 4

• Long-lasting LA
• Not effective topically, can be used for local infiltration anesthesia and for peripheral/central nerve blocks
• Potency/toxicity ~4x lidocaine
• Produces selective sensory blockade with limited motor blockade

Question 5

How are specific nerves located?

Answer 5

• Review anatomic location of nerves
• Relevant landmarks
• Location of major blood vessels

Question 6

Describe basic use of a nerve stimulator?

Answer 6

• One electrode attached to patient’s skin, other attached to coated, hollow e stim needle with exposed tip
• Locator discharges at 1s intervals while needle directed toward the nerve
• As needle approaches the nerve, twitch response observed -> LA administered through hollow needle

Question 7

Lidocaine onset/duration of action when used for local and regional blocks

Answer 7

• Onset time: 10-15min

- Duration of action: 60-120min

Question 8

Available formulations of Bupivacaine

Answer 8

0.5% solution (5mg/mL)

Question 9

Onset and duration of action of Bupivacaine when used for local and regional blocks

Answer 9

• Onset time of 20-30’

- Duration of action of 240-360’

Question 10

Cardiac effects of bupivacaine

Answer 10

• Large doses selectively cardiotoxic
• Accidental IV administration can cause ventricular arrhythmias (premature ventricular depolarizations, ventricular tachycardia, vfib)

Question 11

Cardiac effects of bupivacaine

Answer 11

• Large doses selectively cardiotoxic
• Accidental IV administration can cause ventricular arrhythmias (premature ventricular depolarizations, ventricular tachycardia, vfib)

Question 12

What are other benefits of intraoperative nerve blockade?

Answer 12

• Improves muscle relaxation
• Attenuates autonomic and endocrine responses to surgery
• Reduces anesthetic requirements