Anaesthetics Flashcards
(35 cards)
Give 4 reasons why an elective surgery may be cancelled on the day?
- Current RTI
- Poor control of drug therapy
- Recent MI
- Poor bloodwork
- Uncontrolled HTN or AF
- Logistical issues e.g. emergency case
What are 4 common risks of having anaesthesia/surgery?
4 rare but important?
Common: pain/aches, PONV, sore throat, confusion, dizziness, bladder problems.
Rare: allergy to medication, damage to teeth, slow breathing
Name 1 non-depolarising neuromuscular blocking agents and 1 depolarising?
Non-depolarising = rocuronium, atracurium, pancuronium Depolarising = suxemethonium
What are possible induction agents for anaesthesia?
Propofol, thiopentone, ketamine, etomidate
Which induction agent is mostly used for RSI?
Thiopentone
Which induction agent is used for anaesthesia in TIVA?
Propofol
Ketamine is more commonly used as an induction agents in ?
Paediatrics
Name 3 inhalational agents used to maintain anaesthesia?
Isoflurane, desflurane, sevoflurane
Outline the steps from an awake patient to an asleep patient ready for surgery.
- Pre-oxygenation
- Opioid
- Induction agent
- Inhalational agent for maintenance
- Bag mask
- Muscle relaxant and endo-tracheal intubation
- or just LMA insertion
Outline the steps of a RSI.
Which drugs are typically used?
Which patient’s is it used for?
- Pre-oxygenation
- Sellick’s manoeuvre (cricoid pressure)
- Induction agent and immediate muscle relaxant
- Intubation
Thiopentone and suxamethonium
Used if risk of aspiration of gastric contents
What are the steps involved at the end of an operation to wake a patient up?
- Stop anaesthetic vapours
- Give oxygen
- Suction
- Reverse muscle relaxants
- Once breathing = remove ET tube and give oxygen by mask
- Recovery
What antiemetics are given
a) intraoperatively
b) post operatively?
Ondansetron and dexamethasone
Cyclizine
Which is longer acting, lidocaine or bupivacaine?
Which is more toxic?
Bupivacaine
Bupivicaine
What effect does adding adrenaline to local anaesthetic injection have?
Increased length of action and with lidocaine allows higher doses to be used.
What is the mechanism of action of local anaesthetics?
What are the signs of toxicity?
Na+ channel blocks, prevents depolarisation of nerves
Peri-oral numbness, tinnitus, light-headedness, confusion, LoC, seizures, cardiac collapse.
Management of local anaesthetic toxicity?
Supportive - airway support, cardiac monitoring
Benzos for seizures
IV 20% lipid emulsion (Itralipid) to absorb LA from circulatory system. Bolus and then infusion
What are the layers you progress through when performing a spinal anaesthesia?
At which layers do you get a ‘pop’?
Skin - subcut fat - supraspinatous ligament - interspinatous ligament - ligamentum flavum (pop) - epidural space - dura mater (pop) - arachnoid mater - subarachnoid space
What are some CI to spinal anaesthesia?
Local infection, sepsis, raised ICP, coagulopathies, severe hypovolaemia, pt refusal, severe MS and AS,
SEs of spinal anaesthesia?
Hypotension, sensory and motor block, urinary retention.
Which has a quicker onset: epidural or spinal?
Spinal.
Complications of epidural?
How long do they usually stay in for?
Epidural haematoma/abscess, headache, infection, indwelling urinary catheter required.
Usually 2-3 days e.g. following major surgery. Can be shorter/longer.
What is the Monro Kellie doctrine?
Sum of brain, CSF and intracerebral blood is constant, so increase in one must lead to decrease in one of the other.
What is the equation for cerebral perfusion pressure?
Mean arterial pressure - mean intracranial pressure
What is normal ICP?
7-15mmHg
