LAST

Question 1

Local anesthetic systemic toxicity is a

Answer 1

serious but rare event during regional anesthesia

most commonly occurs from an inadvertent intravascular injection

Question 2

___________ is thought to cause seizures

Answer 2

initial blocking of inhibitory neurons

Question 3

___________ results in bradycardia

Answer 3

blocking of cardiac ion channels

Question 4

The most serious complication of LAST is

Answer 4

ventricular fibrillation

Question 5

_________ drugs are thought to be less cardiotoxic

Answer 5

shorter acting drugs

Question 6

More potent agents have

Answer 6

higher lipid solubility & protein binding

Question 7

The classic clinical presentation of last includes

Answer 7

rapid onset; usually within a minute

Question 8

Subjective symptoms of LAST include

Answer 8

agitation, tinnitus, circumoral numbness, blurred vision, and metallic taste
this is followed by muscle twitching, unconsciousness, and seizures

Question 9

Very high levels of local anesthetic can result in

Answer 9

cardiac and respiratory arrest

Question 10

The most commonly seen incidences of LAST are a result of

Answer 10

epidural
axillary
interscalene

Question 11

Ways to prevent LAST include

Answer 11

test dosing
incremental injection with aspiration
use of pharmacologic markers
ultrasound

Question 12

Treatment of LAST includes:

Answer 12

prompt recognition and diagnosis
airway management priority- seizure suppression with benzodiazepines & succincycholine & prevention of hypoxia & acidosis
Lipid emulsion therapy
vasopressors- epinephrine <1 mg/kg
vasopressin- do not give b/c of risk of pulm. hemorrhage

Question 13

the possible mechanism of action of lipid emulsion therapy is

Answer 13

capture local anesthetic in blood (lipid sink)
increased fatty acid uptake by mitochondria
interference of Na+ channel binding
promotion of calcium entry
accelerated shunting

Question 14

The max dose of lidocaine & mepivacaine is

Answer 14

4 mg/kg; 7 mg/kg with epi

Question 15

The max dose of bupivacaine, ropivacaine, & tetracaine is

Answer 15

3 mg/kg

Question 16

The max dose of chloroprocaine is

Answer 16

11 mg/kg; 14 mg/kg with epi

Question 17

The max dose of prilocaine is

Answer 17

7 mg/kg; 8.5 mg/kg with epi

Question 18

The max dose of procaine is

Answer 18

12 mg/kg

Question 19

Bupivacaine is most likely to cause

Answer 19

LAST because it is longer acting and has a stronger bond

Question 20

Nerve injury can be a result of

Answer 20

direct needle trauma or local anesthetic toxicity

Question 21

The incidence of peripheral nerve injury varies with

Answer 21

location

Question 22

Pre-existing patient factors for nerve injury include

Answer 22

diabetes, pre-existing neurologic disease, smoking, increased BMI, male

Question 23

Local anesthetic neurotoxicity is the result of

Answer 23

dose and concentration of local anesthetic

additive agents, e.g. epinephrine

Question 24

Nerve injury should be evaluated based on

Answer 24

presenting signs & symptoms

Question 25

Patient’s perception of the postoperative course is altered by

Answer 25

postoperative blur

non-operative factors that coincide with the surgical site

Question 26

Ultrasound allows the practitioner to identify important structures close to nerve tissue such as

Answer 26

dural, pleural, vasculature, & bowel