Toxicity Of LA

Question 1

Who are risk of LA toxicity?

Answer 1

Children
Elderly
Medically compromised liver

Question 2

Does LA cause hyper or hypotension?

Answer 2

Hypotension

Question 3

Why acompany adrenaline (vasoconstrictor) with LA?

Answer 3

Longer working time, compensates for vasodilation effects of LA, slows rate of absorption

Question 4

If a patient is taking opioids… what is the effect of using LA?

Answer 4

It is synergistic with sedatives and opioids to produce respiratory depression

Question 5

What LA does not require a vasoconstrictor?

Answer 5

Mepivacaine

Question 6

What vasoconstrictor would you not use on a cardiac patient? what LA would you use?

Answer 6

Adrenaline, use mepivacaine

Question 7

What does the vasoconstrictor felypressin act on?

Answer 7

Vascular smooth muscle, grave,s in venous over after arteriolar

Question 8

What vasoconstrictor crosses the placenta?

Answer 8

Felylressin

Avoid in pregnancy (oxytosin)

Question 9

What LA is accompanied by Felypressin?

Answer 9

Prilocaine

Question 10

Can people be allergic to LA?

Answer 10

No, usually sensitivity to the vasoconstrictor

Question 11

What things should you look out for on a medical history for LA administration?

Answer 11

• cardiovascular
  -asthma
• blood pressure disorders
• diabetes
• epilepsy
• Described medications
• recreational drugs
• tendency to be bruised

Question 12

What are 2 aspects to consider with regards to medically compromised patients?

Answer 12

Underlying conditions

Drug interactions

Question 13

What are cardiac problems for concern?

Answer 13

Arrhythmias, unstable angina, high BP

Question 14

What is an example of high BP?

Answer 14

Systolic 200 mmHg
Diastolic 115 mmHg

Question 15

Why is someone with liver failure at risk of toxicity due to LA?

Answer 15

High risk of toxicity due to impaired metabolism

Liver is the main site of LA metabolism of amides

Question 16

Why not inject into an inflamed site?

Answer 16

Spread infection

Acidosis, lowers pH of tissues, less potent effect of LA

Question 17

Where do you inject for a mandibular block?

Answer 17

Pterygomandibular space

Question 18

What nerve can you hit when trying to hit the alveolar nerve?

Answer 18

Lingual

Question 19

What LA can anaesthitise the first premolars?

Answer 19

Articaine

Question 20

When does facial paralysis occur?

Answer 20

Inject Too high between

Hit the facial nerve at the parotid gland

Question 21

What is a trismus?

Answer 21

Question 22

When can an trismus occur?

Answer 22

Due to intramuscular injection causing bleeding into the medial pterygoid muscle