General Anaesthesia

Question 1

What is anaesthesia?

Answer 1

The absence of sensation

Question 2

What is analgesia?

Answer 2

The absence of pain

Question 3

What is the intention of regional anaesthetics?

Answer 3

Ensure the patient remains conscious and ventilating with haemodynamic stability yet cannot feel pain in a certain part of the body

Question 4

What is an antipyretic?

Answer 4

Anti-temperature agent

Question 5

Give an example of an antipyretic agent

Answer 5

Intravenous paracetamol

Question 6

What is amnesia?

Answer 6

Inability to recall information

Question 7

What is anxiolysis?

Answer 7

Elimination of anxiety

Question 8

What is an antiemetic?

Answer 8

An agent used to reduce nausea and vomiting

Question 9

What are 2 clinical scoring systems used to grade level of consciousness?

Answer 9

1. AVPU

2. Glasgow Coma Score (GCS)

Question 10

What are the 4 components of the AVPU consciousness grading system?

Answer 10

1. Alert
2. Verbal
3. Pain
4. Unresponsive

Question 11

What are the 3 components of the GCS consciousness grading system?

Answer 11

1. Best verbal response
2. Best motor response
3. Best eye contact

Question 12

What is “A Conscious Decision”?

Answer 12

A review of the use of general anaesthesia and conscious sedation in primary dental care

Question 13

What were the 2 main points taken from “A Conscious Decision”?

Answer 13

1. Confinement of general anaesthesia for dentistry within a hospital setting where there was immediate availability of a critical care facility
2. General anaesthesia should be undertaken only when absolutely necessary

Question 14

Name 3 alternatives to general anaesthesia

Answer 14

1. Behaviour management with or without conscious sedation
2. Inhalation sedation
3. Intravenous sedation

Question 15

What is conscious sedation?

Answer 15

A technique where drugs produce state of depression of CNS, but during which verbal contact with the patient is maintained

Question 16

What is the major aim of conscious sedation?

Answer 16

Reduce anxiety of patient and enable procedures to be longer without the need for general anaesthetics

Question 17

Name 3 safety measures which must be taken if a dental professional is providing conscious sedation

Answer 17

1. Operating chairs must be capable of being placed in head down tilt position
2. Equipment for resuscitation from respiratory and cardiac arrest must be available
3. Patients must be escorted home

Question 18

Name 4 types of anaesthesia

Answer 18

1. General anaesthetics
2. Sedation
3. Regional anaesthesia
4. Local anaesthetics

Question 19

What is the major complication with sedation?

Answer 19

Patient can lose consciousness and become apnoeic or go into a state of cardiac arrest

Question 20

What is regional anaesthesia?

Answer 20

Use of local anaesthetics to block specific regions of the peripheral nervous system

Question 21

What is local anaesthesia?

Answer 21

Infiltration of local anaesthetics into the subcutaneous tissues to block innervation of the skin

Question 22

How is epidural anaesthesia delivered?

Answer 22

Via a catheter to allow anaesthetic to be topped up

Question 23

What are 2 ways a nerve can be identified before being anaesthetised?

Answer 23

1. Landmark techniques

2. Ultrasound guidance

Question 24

What are 3 major components of pre-assessment for anaesthesia?

Answer 24

1. History
2. Examination
3. Investigations

Question 25

Name 4 parts of a patient's history to be checked during pre-assessment for anaesthesia?

Answer 25

1. Co-morbidities 2. Previous anaesthesia 3. Allergies 4. Chronic pain medication

Question 26

What are co-morbidities?

Answer 26

Diseases co-occurring with primary problem

Question 27

Why is it important to establish if a patient has previously been anaesthetised?

Answer 27

Their previous reaction can indicate suitability for anaesthesia

Question 28

Name 4 examinations which should be undertaken during the pre-assessment for anaesthesia?

Answer 28

1. BMI 2. Syndromic features 3. Urea biomarkers 4. Creatinine biomarkers

Question 29

Why is BMI important to examine before anaesthesia?

Answer 29

It can have dramatic effect of respiratory system, where a patient can quickly become apnoeic, develop an airway obstruction or go into respiratory arrest

Question 30

Name a possible syndromic feature which could prevent anaesthesia

Answer 30

Treacher Collins syndrome

Question 31

How can urea and creatinine biomarkers be tested?

Answer 31

Renal function tetss

Question 32

Why must kidney function be tested before anaesthesia?

Answer 32

Under preforming kidneys may be unable to deal with massive clearance of the anaesthetic

Question 33

Name 2 investigations which should be taken before anaesthesia

Answer 33

1. ECG | 2. Blood glasses rumere

Question 34

Why is it important to take an ECG before a patient undergoes general anaesthesia?

Answer 34

It tests a patient's anaerobic threshold and can help predict who may need critical care post operation

Question 35

Describe the 7 degrees of anaesthesia

Answer 35

1. Loss of sensation 2. Loss of consciousness 3, Loss of spinal reflex function 4. Loss of ANS function 5. Loss of central homeostatic control 6. Brain stem dysfunction 7. Death

Question 36

What are the 4 stages of anaesthesia (Guedel)?

Answer 36

1. Analgesia and disorientation 2. Excitement and delirium 3. Start of surgical anaesthesia 4. From stoppage of respiration until death

Question 37

Between what 2 events does stage 1 of anaesthesia occur?

Answer 37

Beginning of induction to loss of consciousness

Question 38

Between what 2 events does stage 2 of anaesthesia occur?

Answer 38

Loss of consciousness to onset of automatic breathing

Question 39

Between what 2 events does stage 3 of anaesthesia occur?

Answer 39

Onset of automatic breathing to respiratory paralysis

Question 40

Between what 2 events does stage 4 of anaesthesia occur?

Answer 40

Respiratory paralysis to death

Question 41

What are the 2 methods of inducing anaesthesia?

Answer 41

1. Used at low dose continuously via syringe driver | 2. Anaesthetic machine can deliver specific concentration agent

Question 42

When is pre-medication usually used during the induction of anaesthesia?

Answer 42

Paediatrics

Question 43

Name 3 drugs which can be used as pre-medication during the induction of anaesthesia

Answer 43

1. Oral form of midazolam 2. Nasal spray of fentanyl 3. Oral clonidine

Question 44

What are 3 advantages of pre-medication?

Answer 44

1. Improved induction of anaesthesia 2. Reduced parasympathetic system activity 3. Lower maintenance dose of anaesthesia

Question 45

Name 3 types of inhaled anaesthetic agents

Answer 45

1. Halogenated hydrocarbons 2. Nitrous oxide 3. Xenon

Question 46

What are 3 types of halogenated hydrocarbons?

Answer 46

1. Sevoflurane 2. Isoflurane 3. Desflurane

Question 47

How is nitrous oxide commonly used?

Answer 47

In combination with intravenous midazolam

Question 48

What 4 factors can affect the onset of action of inhaled anaesthetic agents?

Answer 48

1. Solubility of agent in the blood (poor solubility - faster onset) 2. Inhaled concentration of agent (high concentration - faster onset) 3. Lipid solubility of agent 4. Cardiac output of patient (low output - faster onset)

Question 49

Name 5 side effects of inhaled anaesthetic agents

Answer 49

1. Slow onset of action when used as induction agent 2. Effects on respiratory system 3. Halogenated agents reduce mean arterial pressure and cardiac output 4. Reduce hepatic blood flow 5. Can induce nausea and vomiting

Question 50

What is malignant hyperpyrexia?

Answer 50

A condition triggered by drugs used for general anaesthesia which causes drastic increase in oxidative metabolism in skeletal muscle which leads to circulatory collapse and death if untreated

Question 51

Name 2 advantages of intravenous anaesthetics

Answer 51

1. Rapid onset and offset of agent | 2. More predictable response if titrated

Question 52

Name 5 intravenous anaesthetics

Answer 52

1. Thiopentone 2. Propofol 3. Midazolam 4. Etomidate 5. Ketamine

Question 53

Describe midazolam as an intravenous anaesthetic agent

Answer 53

- Used for minor procedures - It is a benzodiazepine so modulates effects of GABA at GABA-A receptors - Flumazenil is a competitive antagonist so can reverse its effects

Question 54

Describe fentanyl as an intravenous anaesthetic agent

Answer 54

- Synthetic phenylpiperidine derivative | - μ receptor agonist

Question 55

Describe propofol as an intravenous anaesthetic agent

Answer 55

- Phenolic derivative which is highly lipid soluble - Dose dependent reduction in cardiac output and systemic vascular resistance which can cause profound drop in blood pressure - Involuntary muscle action common - Pain at site of injection

Question 56

Describe ketamine as an intravenous anaesthetic agent

Answer 56

- Antagonises the excitatory neurotransmitter glutamate at the NMDA receptors within CNS - Increases blood pressure so stable induction of anaesthesia during emergencies - Cause post operative psychotic symptoms

Question 57

What are 2 main types of neuromuscular blocking agents?

Answer 57

1. Non-depolarising neuromuscular blockers | 2. Depolarising neuromuscular blockers

Question 58

Name 2 examples of non-depolarising neuromuscular blockers

Answer 58

1. Aminosteroids and bisbenzylisoquinoliniums | 2. Rocuronium and Atracurium

Question 59

Name an example of a depolarising neuromuscular blocker

Answer 59

Suxamethonium

Question 60

What is the function of neuromuscular blocking agents?

Answer 60

Used to allow the incubation of the trachea