Complications

Question 1

Describe the nature of most LA side effects

Answer 1

Most side effects are minor and reversible

Question 2

What information about medical and drug history should you obtain before an injection (4)

Answer 2

• Previous problems with LA
• Systemic conditions
• Drugs which may interact
• Anxiety/ nervous patients

Question 3

Name some susceptible groups to LA (3)

Answer 3

• Elderly
• Children
• Medically compromised

Question 4

Name some unwanted effects of LA (8)

Answer 4

• Physical trauma
• Chemical trauma
• Bleeding
• Spread of infection
• Toxicity
• Allergy
• Drug interactions
• Inappropriate site of deposition

Question 5

What are the 4 ways unwanted effects may occur?

Answer 5

• Injecting an inappropriate solution
• Injecting too much solution
• Injecting into wrong site
• Bad luck

Question 6

Name some potential allergens in LAs ()

Answer 6

• Esters
• Preservatives (previously)
• Reducing agents (those with sulphur allergies)
• Adrenaline supersensitivyfy

Question 7

Name some drug groups that may interact with LA agents (5)

Answer 7

• Anticonvulsants
• Antimicrobials
• Benzodiazepines
• Beta-adrenergic blockers
• Calcium channel blockers

Question 8

Name some drug groups that may interact with vasoconstrictors (4)

Answer 8

• Beta-adrenergic blockers
• Calcium channel blockers
• Diuretics
• CNS drugs

Question 9

Name some CNS drugs that may interact with vasoconstrictors (4)

Answer 9

• Anti-Parkinson drugs
• Antidepressants
• General anaesthetics
• Drugs of abuse

Question 10

Why is injecting too much solution particularly relevant to children?

Answer 10

Particularly in children as the toxic dose is weight related

Question 11

What is an early sign of LA toxicity?

Why does this occur?

Answer 11

Excitability as the inhibitory actions of the brain are the first to be depressed

Question 12

What follows excitability in signs of LA toxicity

Answer 12

Signs of central nervous system depression that can lead to unconsciousness

Question 13

What is the cause of death from LA overdose?

Answer 13

Respiratory depression

Question 14

Why is it not possible to change to another LA after maximum dose of one has been given?

Answer 14

The effects of local anaesthetic are cumulative

Question 15

What is the main organ that metabolises LA?

Answer 15

Liver

Question 16

What are the 3 sites that causes problems if LA is wrongly injected into?

Answer 16

• Intra-arterial
• Intraveous
• Intraneural

Question 17

How can you reduce the chances of injecting into a blood vessel?

Answer 17

Use of aspirating syringes

Question 18

Intravascular injection may cause what? (4)

Answer 18

• Pain
• Localised blanching
• Cranial effects (ie blindness)
• Systemic effects (ie tachycardia)

Question 19

Injecting into the parotid gland can cause what?

Answer 19

Facial nerve palsy

Question 20

Is facial palsy caused by LA in the parotid gland permanent?

Answer 20

Paralysis will resolve as the effect of the anaesthetic wears off

Question 21

If someone has facial palsy as a result of LA in the parotid gland what advice would you give regarding their eye?

Answer 21

The eye must be protected until motor function is restored

Question 22

Nerve trunk damage. caused by an injection can lead to what? (3)

Answer 22

• Long term anaesthesia (lack of sensation)
• Paraesthesia (‘pins and needles’)
• Dysaesthesia (pain) of sensory nerves

Question 23

What can cause bleeding form an injection?

Which technique can mainly cause this?

Answer 23

• Penetration of both sides of a blood vessel

- Inferior alveolar nerve blocks

Question 24

What are the best ways to avoid complications? (5)

Answer 24

• Take a good medical history/drug history
• Use an aspirating syringe
• Limit the use of regional block anaesthesia
• Use the min volume of LA possible
• Inject the appropriate solution slowly (1ml over 30 seconds)