Maintenance Drugs Flashcards
(17 cards)
1
Q
What is a MAC value?
A
- The amount of volatile gas that is needed to keep 50% of patients asleep when exposed to a standard noxious stimuli
2
Q
What increases the MAC value?
A
- Hyperthermia
- Catecholamines
- Hyperthyroidism
- Hypernatremia
3
Q
What decreases MAC value?
A
- Hypothermia
- Hypoxaemia
- Hypercapnia
- Drugs that affect CNS
- Analgesia agents
- Pregnancy
- Old age
- Hypotension
- Hypothyroidism
4
Q
What is the inhalant effect on the cerebrum?
A
- Decreases metabolic rate
- Decreases cerebral oxygen concentration and blood flow
- Vasodilation
Increases blood volume
5
Q
What is the inhalant effect on the cardiovascular system?
A
- Decreases cardiac output, systemic vascular resistance and arterial BP, due to decreased myocardial contractility and vasodilation
6
Q
What is the inhalant effect on the respiratory system?
A
- Hypercapnia
- Decrease in tidal volume, respiratory rate and minute volume
7
Q
What are the pharmacokinetics of halothane?
A
- 20-25% metabolised by liver
7
Q
What is the inhalant effect on the renal and hepatic system?
A
- Decreased perfusion due to hypotension, which can cause decreased drug metabolism and decreased urine output
8
Q
What is halothane?
A
- Very potent halogenated hydrocarbon
9
Q
What is isoflurane?
A
- Very potent fluorinated ether
10
Q
What are the pharmacokinetics of isoflurane?
A
- Under 1% metabolised by patient
11
Q
What is sevoflurane?
A
- Less potent fluorinated ether
12
Q
What are the pharmacokinetics of sevoflurane?
A
- 3% metabolised by liver
13
Q
What is desflurane?
A
- Fluorinated ether
14
Q
What is nitrous oxide?
A
- Halothane combined with a more potent inhalant
15
Q
What are the side effects of nitrous oxide?
A
- Mild sympathetic stimulation
- Diffusion hypoxia
16
Q
What is the nitrous oxide second gas effect?
A
- Nitrous oxide will increase the rate of uptake of other inhalational agents into the blood stream and therefore an appropriate level of anaesthesia will be reached more quickly
