anaesthetics

Question 1

Conscious sedation:

Answer 1

use of small amounts of anaesthetic or benzodiazepines to produce a ‘sleepy-like’ state. (Maintain verbal contact but feel comfortable)
endoscopy

Question 2

Inhalational or ‘Volatile’ General Anaesthesia.

Answer 2

N2O, chloroform

Question 3

intravenous

Answer 3

Propofol,(rapid), GABA barbiturates rapid GABA ketamine slower NMDA
for induction, kids, trauma, Total intravenous anesthesia

Question 4

Guedel’s signs:

Answer 4

Stage 1: analgesia and consciousness
Stage 2: unconscious, breathing erratic but delirium could occur, leading to an excitement phase.
Stage 3: surgical anaesthesia, with four levels describing increasing depth until breathing weak.
Stage 4: respiratory paralysis and death.

Question 5

Anaesthesia is a combination of;

Answer 5

• Analgesia • Hypnosis (loss of consciousness) • Depression of spinal reflexes • Muscle relaxation (insensibility and immobility)

Question 6

potency

Answer 6

Minimum Alveolar Concentration.
[Alveolar] (at 1atm) at which 50% of subjects fail to move to surgical stimulus (unpremedicated breathing O2/air)
– At equilibrium [alveolar] = [spinal cord]

Question 7

Partition coefficients (solubility)

Answer 7

• Blood:Gas partition (in the blood)
– Low value fast induction and recovery e.g., desflurane
• Oil:Gas partition (in fat)
– Determines potency and slow accumulation due topartition into fat (e.g, halothane

Question 8

What Affects MAC

Answer 8

• Age (High in infants lower in elderly) • Hyperthermia (increased); hypothermia
(decreased) • Pregnancy (increased) • Alcoholism (increased) • Central stimulants (increased) • Other anaesthetics and sedatives (decreased) • Opioids (decreased)

Question 9

target most

Answer 9

• Potentiate GABA activity
• Anxiolysis • Sedation • Anaesthesia
all anaesthetics potentiate
GABA mediated Cl- conductance to
depress CNS activity.

Question 10

target exceptions

Answer 10

Xe,N2O and ketamine , • NMDA receptors probable other site

block central excitation

Question 11

Local and Regional Anaesthesia indication

Answer 11

: Dentistry Obstetrics Regional surgery (patient awake) Post-op (wound pain) Chronic pain management (PHN)

Question 12

Local and Regional Anaesthesia examples

Answer 12

Bupivacaine, Lidocaine, Ropivacaine

Question 13

Local and Regional Anaesthesia mechanism

Answer 13

Block voltage gated sodium channels (VGSCs)

• Adrenaline ↑ duration

Question 14

Regional Anaesthesia.

Answer 14

selectively anaesthetising a part of the body.

Uses local anaesthetic and or an opioid.

Question 15

side effects

Answer 15

vomiting, hypotension, post operative cognitive disfunction, chest infection, allergic reactions/anaphylaxis