Types of anaesthesia Flashcards
(26 cards)
Define anaesthesia.
A state of temporarily induced state of reversible loss of consciousness to facilitate surgery.
What is the anaesthesia triad?
Hypnosis
Analgesia
Muscle relaxation
Name 2 drugs used anaesthetics in the olden days.
Ether and Chloroform
What are the types of anaesthesia?
General anaesthesia and Regional anaesthesia
Define general anaesthesia.
Drug induced reversible depression of the CNS, resulting in loss of response to and perception of all external stimuli.
Define regional anaesthesia.
The art of rendering a part of the body insensible to pain for surgical operation to be conducted
How is GA classified?
GA with Face mask
GA with supraglottic airways
GA with ETT
How is regional anaesthesia classified?
Neuraxial (Spinal, Epidural…)
Nerve blocks- Brachial plexus, wrist, penile, inguinal, sciatic, femoral, ankle blocks,
In what sequence is GA administered?
Premedication
Induction
Muscle Relaxation(if Required)
Maintenance
Analgesia
Name drugs in the following categories that can be used for induction:
a) Intravenous (3)
b) Gas (2)
c) Muscle relaxants (2)
d) Analgesia (1)
a) IV: propofol, Thiopental, Ketamine, etomidate, opioids
b) Gas: Sevoflurane, halothane
c) Muscle relaxants: Suxamethonium, Vecuronium, Rocuronium
d) Analgesic: multimodal
Name 3 drugs that can be used for maintenance.
IV or Gas: sevoflurane, halothane, Isoflurane, Desflurane
What is Propofol Infusion Syndrome (PRIS)?
Propofol infusion syndrome is a rare syndrome of lipaemia, metabolic acidosis, cardiomyopathy and cardiac failure ,skeletal myopathy and death.
Whys premedication done and what can be used?
To get the patient to relax before the operation
And to reduce the sympathetic response to airway management during induction.
This can be achieved by benzodiazepines, opioids
What is added to propofol to inhibit bacterial growth? (2)
Disodium EDTA (0.05 mg/mL) or sodium metabisulfite (0.25 mg/ mL)
Give 4 benefits of propofol.
- Quick onset
- Anti-pruritic
- Anti-emetic
- Anti-convulsant
- Anti-bronchospasm
- Anti-memory
Give 4 side effects of propofol.
- Pain on injection
- Hypotension-dose dependent cardiovascular depression
- Contamination risk
- Apnoea-dose dependent respiratory depression
- Unpleasant burning sensation on injection
- May cause propofol infusion syndrome(PRIS)
Give 2 benefits and side effects of sodium thiopentone.
Benefits
- Smooth loss of consciousness
- A good anti-convulsant
- Brain protection
Side effects
- May cause antanalgesia with small doses
- Cardiac depression
- Potent depressant of the respiratory center
Give 2 benefits and side effects of ketamine.
BENEFITS
- Very effective analgesic agent at sub-anaesthetic doses
- Maybe useful in conditions that you don’t want severe CVS depression.
- Respiratory depression is minimal
Side effects
- Psychic reactions
- Post operative nausea and vomiting relatively common
- May cause uterine contractions in the first trimester.
Define Blood Gas Partition Coefficient (BGPC).
Ratio of the amount of vapour dissolved in the blood vs the amount of vapour in gaseous form (not dissolved)
What can e used for analgesia?
Nsaids/paracetamol
Opioids/opiates
Nerve blocks
Spinal anaesthesia and epidural analgesic techniques
Give 6 indications for GA.
By surgical procedure
- Requiring profound muscle relaxation
- Duration more than 3hrs
- Incision above umbilicus
- Inability to provide comfort with local/regional anaesthesia
By patient
- Airway protection
- Respiratory failure
- Unstable clinical state
- Inability to cooperate/understand
Give 4 advantages of GA.
a) Rapid onset
b) Titration is possible
c) Airway is guaranteed
d) Patient cooperation in not absolutely essential
e) Patient is unconscious
f) Amnesia is present
Give 5 disadvantages of GA.
a) Patient is unconscious
b) Protective reflexes depressed
c) Vital signs are depressed
d) Advanced training required
e) Special equipment required
f) Recovery area should be available
g) Intraoperative complications are more likely to occur during GA
Give 4 examples of local anaesthetics.
Esters- tetracaine, procaine
Amides- Lidocaine / lignocaine, Bupivacaine
