Overview of Anaesthesia

Question 1

General Anaesthesia (GA) Description

Answer 1

Patient in induced reversible coma.
Mainly induced via IV agents (KISS) and 2 inhalation agents (SH)
Patients may breathe spontaneously.
Usually administer analgesia.

Question 2

Local/Regional Anaesthesia Description

Answer 2

Part of body rendered insensitive to pain, sensation and moving by blocking nerves with local agents.
Fully conscious but may be sedated
Specific nerve or whole section is blocked
Includes spinal and epidural

Question 3

GA TRIAD

Answer 3

Hypnosis
Analgesia
Immobility

Question 4

What is Hypnosis?

Answer 4

Refers to loss of consciousness (LOC)
Achieved by GA agents
Induced LOC= mainly IV agents and Inhalation agents (SH)
Maintained LOC= mainly inhale agents and IV agents (PK) by TIVA

Question 5

What is Analgesia?

Answer 5

Affects (depresses) the sympathetic nervous system.
So assess tachycardia and hypertension to determine if patient is in pain.
Usually strong opioids (FM) sometimes regional Anaesthetics (LB)

Question 6

What is Immobility?

Answer 6

Aka muscle relaxation
Immobile surgical field for optimal surgical access.
Used for:
•LARGE BODY CAVITIES the CHEST AND ABDOMEN including C-section.
•MICROSURGERY the Retina and Brain
•Procedures requiring intubation
ALWAYS INTUBATE

Question 7

The PERIOPERATIVE Journey includes:

Answer 7

Preinduction
Induction
Maintenance
Emergence

Question 8

Preinduction/Preoperative

Answer 8

Assess patient
Consent is checked
Theatre prepped 
Equipment checked
IV sited
Giving sedatives to reduce anxiety
Opioids is given preemptively

Question 9

Induction

Answer 9

Mainly IV (KEPT) and inhale (SH)
Airway maintained, protected and secured (give neuromuscular blocker 1-5 minutes prior to intubation.
Pre-oxygenation done here 
LOC confirmed HERE.

Question 10

Maintenance

Answer 10

Mainly inhale agent but TIVA can be done by IV agents (PK).
Do:
• ventilator setting adjusted
• monitoring attachment and siting of IV
• surgical area cleaned and prepped
• WHO SSC done and possible difficulties

Question 11

Emergence

Answer 11

Return Patient’s control of their respiration.
Muscle Relaxants checked and reversed (only Non-Depolarizing)
Respiration and oxygenation must be assessed to be adequate- spontaneous, regular breathing with normal tidal volume and vital signs including SATS. Airway devices (e.g. ET tubes) are removed either deep or on awakening.

Anaesthetic agent is discontinued (usually the inhale agent)- no specific antidote to either the inhalation or intravenous anaesthetic agents
Patient is assessed on the table for a few moments before transfer onto the trolley.

Opioid analgesics cause sedation and contribute to the depth of anaesthesia
Opioid analgesics also suppress respiration

Question 12

The Depth of Anaesthesia

Answer 12

Guedel Stages:
Stage 1: “Analgesia”= from induction to loss of consciousness
Stage 2: “Excitatory phase”= paradoxical disinhibition (excitement, hiccupping, swallowing, writhing about)
Stage 3: “SURGICAL ANAESTHESIA”= eyeballs become fixed (light), diaphragmatic respiration (deep)
Stage 4: “Overdose”=diaphragmatic paralysis, loss of all reflexes leads to death.
“NOT SEEN TYPICALLY SEEN IN RAPIDLY ACTING INTRAVENOUS AGENTS”

Question 13

ProgRessive loss of reflexes

Answer 13

1. Voluntary control of eye movement
2. Eyelash reflex
3. Lid reflex
4. Swallowing, retching and vomiting
5. Conjunctival reflex
6. Muscular tone
7. Corneal reflex
8. Glottic reflexes and control of respiration
9. Pupillary light reflex

Question 14

Postoperative placement

Answer 14

1. Majority= Recovery prior to ward transfer
2. Day Cases= discharged from recovery
3. Special Care Required=
   a) theatre to ICU
   b) theatre to PAHCU