Anaesthetics Flashcards
How do you treat malignant hyperthermia?
Dantrolene
Into which space do epidural blocks go?
Epidural space
(Intrathecal)
What is the main advantage of a endotracheal tube?
Airway protection
Into which space do spinal blocks go?
Subarachnoid
Which broad class of agents are used for muscle relaxant? What are some called? How do they work?
Non-depolarising muslce relaxants
Rocuronium, Vecuronium, Atracurium, Sistracurium
Blocking post synaptic ACh receptor at the neuromuscular junction
What are some options for local anaesthetics? What are their strength and weaknesses’?
Lignocaine - Fast acting, short acting, highly toxicity
Bupivicaine - Slow onset, long acting, low toxicity
What is the dose of suxamethonium for rapid sequence induction intubation?
1-2mg/kg TBW
Which agent is used for maintenance?
Sevofluorone - inhaled volatile agent
Morphine
What is the best measure of the success of ventilation in a GA?
Expired CO2
Which type of regional block has a quicker onset?
Spinal
What are the three phases of anaesthetics?
Induction
Maintenance
Reversal
Which type of regional block uses a greater volume of anaesthetic, spinal or epidural?
Epidural
Which agent is used rapid sequence induction? Why? How does it work?
Suxamethonium
It has a rapid onset ~1min
It is a ACh receptor agonist > causes complete depolarisation that lasts for ~3-5mins
What are some indications for muscle relaxant GA?
Thoracic/Abdo/Neuro surgery
Prone position
Long procedure
How does morphine work?
It’s an agonist to the Mu receptors in the CNS
Compare the location of administration of spinal and epidural blocks?
Spinal is below L1/L2 and it will travel throughout the space
Epidurals are administered at the target site
What are some downsides of suxamethonium?
Causes myalgia
Can trigger malignant hyperthermia
Some patients are deficient in pseudo cholinesterase - sux takes a long time to wean from = ICU on ventilator
What is the utility of spinal blocks?
Caesarians - can’t expose babies to GA
Orthopaedics
What are you concerned about when using regional blocks? How do you manage it?
Both can cause a loss of sympathetic tone and vasodilatation (esp spinals)
Preload the patient with 1L of Hartman’s and prepare a vasopressor
How do you reverse a spontaneous ventilation GA?
Turn O2 up to 100% (turning off the volatile maintenance)
What deficiency causes malignant hyperthermia?
Ryanodine receptor gene deficiency
What are some induction agents? What are their specific roles/doses?
Benzodiazapene - Anxiolytic - 2-5mg IV
Fentanyl - Reduce broncho spasm - 100mcg IV
Propofol - Induce hypnosis - 200mg IV
How are muscle relaxants blocked? What is the name of one such agent?
Acetylcholinesterase inhibitors to increase the ACh at the neuromuscular junction - Neostigmine
ACh is a muscarinic agonist therefore cause bradycardia so must be accompanied with atropine or glycopyyrolate
What is the triad of anaesthetics?
Hypnosis
Analgesia
Immobility
Which patients are at higher risk of aspiration?
Trauma/ED
Full stomach
GORD
Pregnant
Bowel obstruction
OSA
Obesity
What are the two types of GA’s?
Spontaneous ventilation
Muscle relaxant GA
What type of airway aduvant is required for a spontaneous ventilation GA?
Laryngeal mask
When is rapid sequence induction required?
When there is high risk of aspiration, usually due to a full stomach - trauma/ED cases
What are some risk factors for developing post operative NV (OPNV)
Female
Younger age
Non-smoking
Hx of OPNV
When is spontaneous ventilation GA indicated?
Quick
Minimally invasive
Superficial procedures
