Local Anaesthetics: Complications

Question 1

List the systemic complications associated with local anaesthetic.

Answer 1

Psychogenic - faint (vasovagal response)

Allergy

Drug interactions

Toxicity - overdose

Cross infection

Question 2

What is the most common systemic complication?

Answer 2

Vasovagal response - faint

Question 3

What are the clinical features of a vasovagal response?

Answer 3

Palor
Lightheadedness 
Sweating 
Bradycardia - slow pulse 
Nausea 
Pupil dilation

Question 4

How do you manage a patient who has fainted?

Answer 4

Lay them flat
Elevate the legs
Loosen clothing around the neck
Give them glucose

Question 5

What component of LA are patients usually allergic to?

Answer 5

The preservatives

methylparaben/propylparaben

Question 6

What are the clinical features of an allergy to LA?

Answer 6

Skin rash

Respiratory issues

Anaphylaxis

Question 7

Describe the response that occurs in a patient experiencing LA toxicity?

Answer 7

Convulsions
Circulatory collapse
Respiratory depression
Loss of consciousness

Question 8

What response is similar to the LA toxicity?

Answer 8

Fainting

Question 9

What vasoconstrictor must you avoid in pregnancy?

Answer 9

Octapressin/felypressin.

Question 10

If a patient complains of an “allergy to local anaesthetic” what are they usually referring to?

Answer 10

Adrenaline response

Question 11

What occurs in the adrenaline response?

Answer 11

Adrenaline increases the heart rate, cardiac output, force of contraction, excitability of cardiac muscle.

Question 12

What medically compromised patients must be considered when administering a LA with a vasoconstrictor?

Answer 12

Patients with;

Cardiovascular disease
Hyperthyroidism
Hypertension
Patient who take drugs i.e. cocaine (drug interaction)

Question 13

What drugs interact with Local anaesthetics?

Answer 13

Beta blockers

Diuretics (non-potassium sparing)

Tricyclics

Cocaine

Question 14

List the local complications of local anaesthetic. (11)

Answer 14

Failure to achieve anaesthesia

Prolonged anaesthesia

Pain during and after

Trismus

Haematoma - bleed after injection

Iv injection

Fractured needle

Contamination

Facial paresis

Soft tissue damage

Infection

Question 15

Why would a patient failure to be anaesthetised after LA?

Answer 15

Bad technique

Infection is present

Question 16

What would occur during administering LA that would cause the effects to be prolonged?

Answer 16

Direct image to the nerve by the needle - tear or sever the nerve

Chemical damage to the nerve - solution injected into the near quickly.

Question 17

What would cause LA be painful during and after treatment?

Answer 17

If the solution was injected too quickly

Question 18

What could occur whilst administering LA that could cause trismus?

Answer 18

Injecting into the medial pterygoid.

Question 19

How long can trismus last after LA trauma?

Answer 19

weeks - months

Question 20

How can Trismus induced by LA trauma be treated?

Answer 20

Anti-inflammatory medication

Muscle relaxants i.e diazepam

Question 21

How do you detect if your injection has accidentally become intra-vascular?

Answer 21

Aspirate once inserting the needing.

if IV - blood will enter the cartridge and turn pink/red.

Question 22

What would the patient experience if the LA containing a vasoconstrictor became intra-vascular?

Answer 22

Palpitations
Sweating
Headache
Anxious

(all effects of adrenaline)

Question 23

In terms of administering LA, how would facial paresis be causes?

Answer 23

The needle enters the parotid gland and anaesthetic is injected around the facial nerve

Question 24

How do you differentiate between a stroke and temporary facial paresis?

Answer 24

Stroke:
Ability to wrinkle the forehead.
Ask the patient to grab your fingers with both hands - with a stroke there is reduced function in the arm.
(FAST) - Face, arm, speech etc.

Facial paresis - total unilateral paresis of face.