Anaesthetics Flashcards
At what level does the spinal cord end?
L2/3
At what spinal level are spinal anaesthetics typically given?
L3/4
What kind of anaesthetic agent are typically used in spinal anaesthetics?
Local anaesthetic (Lidocaine, tetracaine, and bupivacaine etc.)
Into which space is spinal anaesthesia administed?
Sub-arachnoid space (between arachnoid and pia mater)
Where is the spinal epidural space found?
Between the dura and arachnoid mater
What are the major complications of spinal/epidural anaesthesia to be aware of?
Meningitis, post-puncture headache
How long before general/regional anaesthesia should patients avoid food?
6 hours
How long before general/regional anaesthesia should patients avoid water?
2 hours
Which common medications should be withheld before anaesthesia?
Anti-hypertensives, esp. ACEIs and diuretics NSAIDs Anti-platelet agents Anti-coagulants Metformin Insulin
For how long before surgery should Aspirin be with-held?
7-10 days
For how long before surgery should Warfarin be with-held?
5 days
For how long before surgery should Clopidogrel be with-held?
7 days
For how long before surgery should DOACs be with-held?
2 days
Which classification is used to describe patient’s physical fitness for anaesthesia?
ASA
What is the triad of general anaesthesia?
Hypnosis, paralysis, analgesia
Give examples of volatile sedating agents.
Nitrous Oxide (Obs/Paeds), Sevoflurane
Give examples of IV sedating agents.
Profolol, Etomidate, Ketamine
What is the primary mechanism of profolol?
GABA-mediated
What is the main side effect of profolol to be aware of?
Hypotension
Which agents may be used during surgery to raise BP?
Metaraminol, ephedrine
Nociceptive pain is relayed by which kind of nerve fibres?
A-delta and C fibres
In which tract would pain signals travel up the spinal cord?
Spinothalamic tract
Which part of the pain pathway influences your pain threshold?
Modulation
What is meant by modulation in the pain pathway?
Inhibitory signal/descending inhibition to decrease pain
Opioids in spinal anaesthesia can evoke which side effect?
Itch
What are the main differences between epidural and spinal for patients?
Epidural takes 15 mins to work, spinal is instant. Epidural usually fitted with catheter to allow further administration
How long before surgery should COCP/HRT be stopped?
4 weeks due to VTE risk
Which rare but life-threatening side effect is associated with halogenated volatile agents?
Malignant hyperthermia
Which IV sedating agent also contains anti-emetic properties?
Propofol
Thiopental is contra-indicated in which group of patients?
Asthmatics (causes bronchoconstriction)
Give a side effect of etomidate.
Adrenal suppression
Which sedating agent may be favoured in trauma?
Ketamine (as does not cause hypotension)
Depolarising agents such as suxamethonium may lead to which side effect?
Malignant hyperthermia
What is the treatment for malignant hyperthermia?
Dantrolene
What is the most common site for IO access?
Proximal tibia
What should you do if a peri-operative transfusion is unlikely?
Group & save
What should you do if a peri-operative transfusion is likely?
Cross-match 2 units
What should you do if a peri-operative transfusion will definitely be needed?
Crossmatch 4-6 units
What are the step-wise airway management steps?
Head tilt, chin lift Jaw thrust OPA NPA iGel Intubation Surgical airway
How is an oropharyngeal (Guidel) airway sized?
Incisor to ear
How is an oropharyngeal (Guidel) airway inserted?
Inserted upside down and turned round
How is a nasopharyngeal airway measured?
Nostril to ear
Nasopharyngeal airways are contra-indicated in…
Base of skull #
What size of iGel will the average adult require?
4
