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Basic Science
intermediate
X-Type

Local Anesthetics in Orthopaedics

Pharmacology

A 45-year-old woman is undergoing ultrasound-guided interscalene block for shoulder arthroscopy. The anesthesiologist is using bupivacaine with epinephrine. Shortly after injection, the patient complains of a metallic taste in her mouth and becomes confused. She develops circumoral numbness followed by twitching of her facial muscles. Regarding local anesthetics in orthopaedic surgery:

Mark each as TRUE or FALSE

A

Local anesthetics block sodium channels, preventing nerve conduction; they are classified as amides ...

B

Lidocaine has rapid onset and intermediate duration (1-2 hours), while bupivacaine has slower onset ...

C

Local anesthetics block potassium channels; esters are metabolized by the liver; ester anesthetics h...

D

Local anesthetic systemic toxicity (LAST) presents with CNS symptoms first (metallic taste, circumor...

E

Peripheral nerve blocks provide excellent analgesia for orthopaedic procedures; ultrasound guidance ...

Answer the questions to see explanations

Click T (True) or F (False) for each option