Lecture 10 - Inhalation and Intravenous Anaesthetics - Part II

Question 1

Types of intravenous anaesthetics - GABA induction?

Answer 1

thiopentone, propofol, etomidate, midazolam; prolong Cl- current, hyperpolarisation

Question 2

Types of intravenous anaesthetics - glutamate inhibition?

Answer 2

ketamine; bind to PCP receptor, antagonise glutamate, suppress excitation, analgesic effects

Question 3

Pharmacokinetics of intravenous anaesthetics?

Answer 3

lipid soluble and cross BBB, IV bolus taken up by vessel rich group organs , leaves organs to tissue falling blood conc., offset of effect therefore by redistribution

Question 4

Thiopentone?

Answer 4

rapid onset, rapid offset, slow clearance (accumulation), induces liver enzymes, BP reduction, respiratory depression

Question 5

Propofol?

Answer 5

moderate onset, rapid offset, fast clearance, liver metabolised, significan BP drop, respiratory depression

Question 6

Propofol vs thiopentone - difference?

Answer 6

propofol wears off faster, less accumulation and hangover effect

Question 7

Propofol vs thipentone - similarity?

Answer 7

both can cause CV instability

Question 8

Etomidate?

Answer 8

CV stable, less respiratory depression, rapid clearance, adrenocortical inhibition (reduces stress hormone levels for decreased recovery)

Question 9

Ketamine?

Answer 9

analgesic, CV stimulant (good for patients in shock), preserves respiratory system, not good for neurosurgery (increases CBF and ICP), dysphoria inducive

Question 10

Midazolam?

Answer 10

didnt talk about in lecture - has very high margin of safety

Question 11

Total intravenous anaesthesia?

Answer 11

avoids inhalation route, avoids complications of vapours (hyperthermia, intracranial hypertesntion); but is expensive with no agent monitoring.