2-1 Murrell-Lagnado

Question 1

Ether

Answer 1

Inhalation anaesthetic
High solubility in blood, slow induction and recovery
Respiration rate is limiting factor
High Kblood/gas - concs below what is needed for unconsciousness can still produce anaesthetic hangover

Question 2

Etomidate

Answer 2

IV anaesthetic
Metabolised rapidly
Target GABA-A receptor - prolong GABAergic IPSPs
More effective on receptors with B2 and B3 subunits

Question 3

Halothane

Answer 3

Inhalation anaesthetic
High blood solubility, slow induction and recovery
Respiration is limiting factor
Potentiation of GABA-A receptors
Potentiation of glycine receptors in medullary neurones
TREK-1 - 2 pore domain K channel also target

Question 4

Nitrous oxide

Answer 4

Inhalation anaesthetic
Low solubility in blood, fast induction and recovery
Limiting factor is cardiac output

Question 5

Propofol

Answer 5

IV anaesthetic
Metabolised rapidly
Target GABA-A receptor - prolong GABAergic IPSPs
Used for maintenance and induction of anaesthesia

Question 6

Thiopental / Thiopentone

Answer 6

IV anaesthesia
Barbiturate with high lipid solubility
Fast redistribution phase - diffuses out of high blood flow tissues into low blood flow tissues (fat)
Recovery of consciousness due to redistribution not elimination of drug
Intermediate phase - diffuses out of lean tissue but into fat
Terminal phase - most has accumulated in fat, some metabolised
Metabolised slowly, so prolonged effects