Inhalational Anaesthetic Agents Flashcards Preview

Anaesthesia > Inhalational Anaesthetic Agents > Flashcards

Flashcards in Inhalational Anaesthetic Agents Deck (62):
1

Which component of the triad to the Inhalational AA Provide

Hypnotic component

2

Name the only inorganic molecule of the I AA

Nitrous Oxide

3

Is Nitrous Oxide a gas or volatile liquid at room temperature?

It is a gas

4

List organic inhalational agents

Halothane
Isoflurane
Desflurane
Enflurane
Sevoflurane

5

Name the two most commonly used inhalational agents for gas inductions

Halothane
Servoflurane

6

In which group of patients would you use inhalational induction

Paediatrics
Patients with compromised airways

7

What inhalational agent is used to provide analgesia in labour and in what form is it provided

Nitrous oxide in the form of Entonox

8

What are the two advantages of combining Nitrous Oxide with an inhalational agent

It speeds up inhalational induction via second gas effect
Reduces the concentration of potent volatile agent required for maintenance

9

What are the features of an ideal inhalational agent

Cheap
Stable
Potent
No metabolism
No long term effects
Non-irritant odor
No resp depression
No CVS depression
Hypnotic and Analgesic
Readily reversible, neuroprotective, non-excitatory

10

What are the three factors which affect the concentration of Inspired Anaesthetic Agent

1. Volume of breathing Circuit
2. Fresh Gas Flow Rate
3. Absorption of inhalational agent by the breathing system

11

List factors which affect the alveolar concentration of anaesthetic agent

1. Inspired concentration of agent
2. Uptake of agent from alveolar to blood
3. Alveolar Ventilation

12

On what parameters is the Uptake of the agent from alveolar to pulmonary circulation dependent upon?

1. Solubility of the agent in blood also known as the blood: gas partition coefficient (BGPC)
2. Cardiac Output
3. Alveolar to mixed venous partial pressure difference

13

List the factors which affect the arterial concentration of agent?

1. Intra-pulmonary shunts: atelectasis, bronchial
intubation

2. Intra-cardiac shunts: ASD, VSD, Tetralogy of Fallot

14

What parameter is analysed to determined the potency of an inhalational agent

MAC: Mean Alveolar Concentration

15

Define MAC or MAC50

It is the steady-state minimum alveolar concentration at sea level
That prevents movement to a standard surgical stimulus (skin incision)
In 50% of non pre-medicated adults

16

How would you calculate the MAC95 from the MAC

I would multiply the MAC by 1.3

17

State the relationship between the MAC and potency of an inhalational agent

Agents with a high potency have a low MAC

18

List factors that would increase the MAC

Infancy
Hyperthermia
Hyperthyroidism
Catecholamines and sympathomimetics
Chronic opioid use
Chronic alcohol intake
Acute amphetamine intake
Hyperntraemia
Beware: Redheads (Require 20% more)

19

List Factors that would decrease the MAC

Neonates
Elderly
Pregnancy
Hypotension
Hypothermia
Hypothyroidism
Sedatives
Alpha 2 agonists
Acute alcohol intake
Acute opioid use
Chronic amphetamine intake
Lithium

20

List factors that do not influence MAC

Gender
Duration of anaesthesia
Time of the day
Hypocarbia

21

What is the cylinder and pipeline colour of nitrous oxide?

French Blue

22

What is the MAC of Nitrous Oxide?

105%

23

What is the maximum safe dose of Nitrous Oxide

70%

24

What properties make nitrous oxide a suitable agent for inhalational anaesthesia

It is pleasant-smelling
It makes induction by a volatile liquid rapid

25

What are the side effects of Nitrous Oxide

CVS depression due to negative inotropy when used with high dose opiates

May aggravate Pneumothorax, Pneumomediastinum, Pneumocephalus

26

What are the toxic effects of nitrous oxide

PONV
Bone Marrow Depression
It is addictive
It is a greenhouse gas

27

What is the color code of halothane

Red

28

What is the MAC of halothane

0.75%

29

What are the CNS effects of halothane

Increases cerebral blood flow
Increases ICP
It has a hangover effect
Recovery is slow

30

What are the CVS effects of halothane

Hypotension
Myocardial depression
Vasodilation
Dysrhythmias (Sinus bradycardia)
Sensitizes the heart to catecholamines

31

What are the Resp effects of halothane

Resp depression
Increases Resp rate
Decreases Tidal volume
Good bronchodilation

32

What are the skeletal muscle effects of halothane

Muscle relaxation
Malignant hyperthermia

33

What are the Uterine effects of halothane

Uterine Relaxation
Risk of Bleeding in C-section

34

What are the hepatic effects of halothane

Halothane hepatitis (very rare)

35

What is the most widely used inhalational agent at GSH

Isoflurane

36

What is the color code of isoflurane

Purple

37

What is the MAC of isoflurane

1.2%

38

What are the resp effects of isoflurane

Irritant to airways
Respiratory depressant

39

Which inhalational agent would you use in neuro-anaesthesia and why?

Isoflurane because it has the least effect in cerebral blood flow and intracranial pressure

40

What are the CVS effects of isoflurane

Minimal Myocardial depression
Peripheral vasodilation
Hypotension
Tachycardia in young patients

41

What are the hepatic effects of isoflurane

Enzyme elevation
Reduced total hepatic blood flow
Preserves hepatic arterial blood flow

42

Isoflurane is the best agent for use in patients with hepatic disease. True/False

True

43

What are the skeletal muscle effects of Isoflurane

Relaxarion
Potentiates non-depolarisers
Precipitates Malignant Hyperthermia

44

What are the uterine effects of halothane

Relaxation but less so than halothane

45

True/False. Isoflurane does NOT produce good operative conditions for the eye.

False.

46

What is the MAC of sevoflurane

2%

47

What is the color code of sevoflurane

Yellow

48

Why is sevoflurane the most popular agent for induction?

It is pleasant to inhale AND
It has a rapid onset of action

49

Name two conditions which commonly occur on emergence from sevoflurane

Muscle rigidity
Emergence delirium

50

True/False. The CNS effects of sevoflurane are similar to isoflurane and desflurane

True

51

What are the CVS effects of sevoflurane?

Mild myocardial depression
Decreased SVR
Prolongs q-T interval on ECG

52

True/False: (a) Sevoflurane does not sensitise the myocardium to catecholamines (b) Sevoflurane induces dysrhythmias

(a) True
(b) False

53

True or False. Sevoflurane is the agent of choice in cardiac patients.

True

54

Are the respiratory effects of sevoflurane similar to halothane and isoflurane? Yes/No/Partly

Partly. It is also non-irritant and bronchodilator.

55

What is compound A?

It is a potentially nephrotoxic end product found when sevoflurane is exposed to soda lime in circle systems

56

With which gase's color code would you confuse desflurane and why?

Nitrous oxide, because the color code of nitrous oxide is french blue while the color code of desflurane is sky blue

57

Why is desflurane not used for inhalational induction

It is irritant and unpleasant

58

What is the danger of desflurane

Associated with the production of toxic concentrations of carbon monoxide when exposed to dry soda lime

59

What is the MAC of desflurane

6%

60

Which agent is contra-indicated in neurosurgery and why?

Enflurane. It raises ICP.

61

What neurological condition is enflurane avoided in and why?

Epilepsy because it provokes epileptiform activity on the EEG

62

What is the (a) color code (b) MAC of enflurane

(a) Orange (b) 1.7%