Anaesthetics Basics

Question 1

Explain the purpose of induction agents

Answer 1

Used to induce loss of consciousness in one to two brain-arm circulations

Question 2

Name the most commonly used induction agent

Answer 2

Propofol

Question 3

What is the normal dosage for propofol?

Answer 3

1.5-2.5mg/kg

Question 4

Positives of propofol?

Answer 4

Excellent suppression of airway reflexes

Reduces incidence of PONV (post-operative nausea/vomiting)

Question 5

What induction agent is commonly used for rapid sequence induction?

Answer 5

Thiopentone

Question 6

What is RSI?

Answer 6

Rapid sequence induction: an established method of inducing anaesthesia in patients who are at risk of aspiration of gastric contents into the lungs e.g trauma, when you don’t know whats in the stomach and need to be put under quickly

Question 7

What is thiopentone codraindicated in?

Answer 7

Porphyria

Question 8

Which induction agent has anti-epileptic properties and protects the brain?

Answer 8

Thiopentone

Question 9

What occurs if thiopentone is injected into an artery?

Answer 9

Thrombosis and gangrene

Question 10

What is the dosage of Thiopentone?

Answer 10

4-5mg/kg

Question 11

What anaesthetic is recommended for short procedures/ use in the field?

Answer 11

Ketamine

Question 12

What effect does Ketamine have on BP and HR?

Answer 12

Increases

Question 13

A patient is confused, with anterograde amnesia, which induction agent have they been given?

Answer 13

Ketamine

Question 14

Dosage of Ketamine?

Answer 14

1.0-1.5mg/kg

Question 15

Which induction agent is recommended for haemodynamic stability? (good for cardiac sensitive situations)

Answer 15

Etomidate

Question 16

What is the dosage of etomidate?

Answer 16

0.3mg/kg

Question 17

Why does -etomidate have a high mortality rate in sepsis?

Answer 17

Adreno-cortical suppression

Question 18

What is the purpose of inhalation agents?

Answer 18

Used to keep patients asleep after use of induction agents

Question 19

When would an inhalation agent be used for induction?

Answer 19

Patients afraid of needles (paeds)

Question 20

What is meant by MAC?

Answer 20

Minimum alveolar concentration (Concentration of the vapour that prevents the reaction to a standard surgical stimulus (traditionally a set depth and width of skin incision) in 50% of subjects.

Question 21

Which inhalaton agent is recommended in children?

Answer 21

Sevoflurane (sweet smelling)

Question 22

Which inhalation agent is recommended for long operations?

Answer 22

Desflurane

Question 23

Which inhalation agent is known for a rapid onset and offset?

Answer 23

Desflurane

Question 24

Which inhalation agent is recommended for organ retrieval and why?

Answer 24

Isoflurane due its minimal effect on organ blood flow

Question 25

What is given prior to induction?

Answer 25

Analgesia

Question 26

What is analgesia required for?

Answer 26

``` Insertion of airway Laryngeal mask airway Intubation Intraoperative pain relief Post-operative pain relief ```

Question 27

Give three examples of short acting opiods

Answer 27

Fentanyl Remifentanil Alfentanil

Question 28

What is the most commonly used analgesic?

Answer 28

Paracetamol

Question 29

Diclofenac and Parcoxib are what types of painkiller?

Answer 29

NSAIDS

Question 30

Explain the physiology of muscle contraction

Answer 30

As an action potential arrives at a neuro-muscular junction acetylcholine is released. This causes depolarisation of Nicotinic receptors leading to muscle contraction

Question 31

How do depolarising muscle relaxants work?

Answer 31

Act on nicotinic receptors in the same way as acetylcholine, however are very slowly hydrolysed by acetylcholinesterase. This causes muscle contraction. The muscle then fatigues and relaxes.

Question 32

What is the most common depolarising muscle relaxant?

Answer 32

Suxamethonium

Question 33

Which muscle relaxant is used for RSI?

Answer 33

Suxamethonium

Question 34

Adverse effects of Suxamethonium

Answer 34

``` Muscle pains fasciculations hyperkalaemia Malignant hyperthermia Rise in ICP, IOP and gastric pressure ```

Question 35

Non-depolarising muscle relaxants have ..... onset and variable onset

Answer 35

slow

Question 36

Name two short acting non-depolarising muscle relaxants

Answer 36

Atracurium | Mivacurium

Question 37

Name two intermediate acting non-depolarising muscle relaxants

Answer 37

Vecuronium | Recuronium

Question 38

Name a long acting non-depolarising muscle relaxants

Answer 38

Pancuronium

Question 39

What is Neostigmine used for?

Answer 39

It is an anti-cholinerase used to reverse muscle relaxants by preventing breakdown of acetlycholinesterase

Question 40

Glycopyrrolate is combined with what to reverse muscle relaxant

Answer 40

Neostigmine

Question 41

What effect does ephedrine have on HR and contractility?

Answer 41

Rise in HR and contractility (this increases O2 required for heart) leading to rise in BP (direct and indirect action, alpha and Beta receptors)

Question 42

Which two drugs cause a rise in BP by vasoconstriction?

Answer 42

Phenylephrine | Metaraminol

Question 43

What medications are used to maintain BP in sever hypotension (sepsis, ICU)?

Answer 43

Noradrenaline Adrenaline Dobutamine

Question 44

Why are anti-emetics used post operatively?

Answer 44

To prevent PONV

Question 45

Name three anti-emetic agents

Answer 45

Ondansetron (commonly used) Cyclizine (anti-histamine) Dexamethasone (Steroids, given only in unconscious patients as causes stinging on administration) Metoclopramide (anti-dopaminergic)