IV Induction Agents Flashcards
An ideal induction agent must be….
- Cheap
- Initiate no venous sequelae
- Have a long shell life
- Must be safe to use
- Must be stable
- No pain on injection
- Must have analgesic properties
- Must be safe if mistakenly injected into an artery
- Should not cause too much cardiac and respiratory depression
- Rapid onset
- Rapid recovery
The Five Classes of IV Induction Agents are:
- Barbiturates eg. Thiopentone
- Imidazole eg. Etomidate
- Benzodiazepines eg. Midazolam
- Phenols eg. Propofol
- Phenylcyclidines eg. Ketamine
When all other drugs have failed in a patient in status epilepticus …….. is indicated.
Propofol
What drug is used for ICU and TIVA sedations because patients can easily recover as a result of the rapid recovery action with minimal hangover?
Propofol
What are the stages of anaesthesia?
- Induction
- Excitement
- Surgical Anaesthesia
- Medullary paralysis
At what stage of anaesthesia is surgery done?
Surgical Anaesthesia
At the medullary stage of anaesthesia there could be?
Irreversible nerve damage
Which drug causes marked adrenal supression to the extent that it is really used clinically?
Etomidate
Among all induction agents which drug causes the most marked fall in BP?
Propofol
The lack of antimicrobial property of this drug means that it has to be used immediately after it’s preparation
Propofol
This drug posses antimicrobial activity specifically of the bacteriostatic type so it can even be used 24-48hrs after its preparation.
Thiopentone
State whether these drugs are indicated or not indicated in surgeries where a laryngeal mask airway would be used and give one reason why
i. Thiopentone
ii. Propofol
i. Thiopentone:
It is not indicated due to the fact that it preserves airway reflexes
ii. Propofol:
It is indicated due to the fact that it causes a significant reduction in in airway and laryngeal reflexes
…… has the most stable effect on the cardiovascular system.
Etomidate
11 beta hydroxylase, a critical enzyme in adrenal steroid production is inhibited by?
Etomidate
Which IV induction agent must be flashed before muscle relaxants are given to prevent the formation of crystals in blood vessels?
Thiopentone
Which IV induction agent has a significant amnesia effect and has Flumazenil 100mcg as its reversal agent?
Midazolam
Which Induction agent can be given through all roots?
Ketamine
Which induction agent has the slowest onset time of up to 2mins?
Ketamine
The active metabolite of Ketamine which is a cerebral stimulant is known as?
Norketamine
In relation to Obstetrics give comments on the following IV induction agents:
i. Propofol
ii. Thiopentone
i. Propofol:
It crosses the placenta but safety of the newborn has not been established so it is contraindicated in neonates, lactating mothers and pregnant women.
i. Thiopentone
It crosses the placenta but it is in a low concentration in the foetus so it has no teratogenic action
Action of Ketamine on the CNS results in:
a) Increased CBF, CMR and ICP
b) Amnesia
c) Emergence phenomena
d) Hangover effect
e) Dissociative anaesthesia
a) Increased CBF, CMR and ICP - TRUE
b) Amnesia - TRUE
c) Emergence phenomena - TRUE
d) Hangover effect - TRUE
e) Dissociative anaesthesia - TRUE
Which of the following are unsafe in porphyria (i.e. can precipitate porphyria)
a) Thiopentone
b) Etomidate
c) Propofol
a) Thiopentone - TRUE
b) Etomidate - TRUE
c) Propofol - FALSE
Which IV induction agent has analgesic property at sub analgesic dose and can be used in patients with hypovolaemia?
Ketamine
