ANAESTHETICS STUDY GUIDE

Dr Rowan Molnar

AIMS OF ANAESTHETIC ATTACHMENT

To understand the scope of the practice of anaesthesia. To understand the role of the anaesthetist as part of the surgical or

procedural team. To gain exposure to airway management and other procedural

skills To understand the importance of the perioperative process

including pre-anaesthetic assessment, investigations, and optimisation.

To understand post anaesthetic care including pain management, and the indications for specialised postanaesthetic monitoring & support.

To revise/enhance key concepts & simple competencies in emergency assessment and resuscitation, including CPR/BLS/ALS.

For those interested, to acquire insight into anaesthetics as a medical career option.

MY FIRST EVER WEEKEND ON DUTY AS AN ANAESTHETICS REGISTRAR . . .

Case transferred from country hospital for theatre:

3 year old girl, previously well Mixed total/partial toe amputation

(From playing with grandfather’s axe!) 18 hours ago, fasted since IV in situ, IV fluids running. Has had antibiotics/narcotic analgesics.No problem, even for a junior registrar,

right?

WHAT HAPPENED NEXT . . . To OT as scheduled. Rapid sequence induction, uneventful

anaesthesia. Extubated near awake at end (in hindsight,

too soon) Vomited undigested food, developed

laryngospasm, desaturated. Re-paralysed, intubated, pharynx sucked out,

suction down ET tube – no evidence aspiration

Awoken & re-extubated uneventfully.

THE LESSONS FROM THIS: Specific: Beware occult delayed

gastric emptying – predictable in hindsight.

General:1. There is minor surgery but there is no

minor anaesthesia!2. Anaesthetic practice is more than

just being able to give an anaesthetic – just like being a 747 captain is more than just holding the controls!

PART I:SCOPE & DEVELOPMENT OF ANAESTHETIC

PRACTICE

IMAGINE A WORLD WITHOUT ANAESTHESIA . . .

WHAT MEDICINE WAS LIKE PRIOR TO THE INVENTION OF ANAESTHESIA:

Surgical operations performed rarely & only as a last resort. Death was the expected and usual outcome, from shock, haemorrhage, or infection.

When surgery unavoidable, patient was held down by assistants & surgeons operated as fast as possible. The first incision was often deliberately brutal in the hope that the patient would faint, allowing less haste.

No analgesia in labour & interventional/operative obstetrics essentially unknown – except post mortem (original meaning of Caesarean Section)

WITHOUT ANAESTHESIA . . .

Surgical advances would have been minimal. Childbirth would remain a major risk for baby

and/or mother. Concepts of intensive care & resuscitation

would not have developed. Pain - acute and chronic - would have remained

an inevitable part of life.

Without doubt the development of anaesthesia has been one of the top ten medical advances of all time.

Some have even ranked it as the most important medical invention ever.

Others rank it amongst greatest discoveries of any type in human history.

BUT WHAT IS ANAESTHESIA?A state that encompasses (1)analgesia plus (2)

arreflexia (muscle relaxation or lack of movement) and (in the case of general anaesthesia) (3) hypnosis; enabling painful or distressing procedures to be performed humanely.

This is the “Triad of Anaesthesia”

THE OTHER TRIAD OF ANAESTHESIA

THE MISSION IS (in order of importance):1. Preserve life

2. Relieve suffering

3. Provide optimum conditions for procedure

(Any fool can do the third by ignoring the first. Doing the second by ignoring the first is

called euthanasia. The art is in being able to provide all three.)

ANAESTHESIA CAN BE: Cerebral

Sedation/analgesiaGeneral

Inhalational/spontaneous ventilatingBalanced/controlled ventilation

Neuro-interruptiveLocalRegionalNeuraxial

(Or some combination of two or more of these)

CLASSIFICATION OF ANAESTHETICS

General Regional

Anaesthesia

Controlledventilation

Spontaneousventilation

Intubated

LMA

Mask

Intubated

Manual

Mechanical

Surface/topicalinfiltration

Nerve/plexus block

Spinal blocks

Subarachnoid Epidural:cervical, thoracic,

lumbar, caudal

Single shot, intermittent, continuous

Dissociative

Auditory

Electrical

Hypnosis

Acupuncture

Local anaesthetic, narcotic/adjuvant, combination

Alternative

BUT WAIT . . . THERE’S MORE:

SCOPE OF ANAESTHETIC PRACTICE Anaesthesia for surgery Sedation/anaesthesia for other procedures Obstetric analgesia/anaesthesia services Pre-anaesthetic assessment & perioperative

medicine Acute & Chronic Pain Services Vascular access services: Central venous lines, et

al. Resuscitation: Trauma team/MET/Prehospital Teaching: Procedural skills/resuscitation/analgesia Intensive Care practice/cover/support Operating theatre management/coordination Critical care transport

(It’s a broad church!)