Anaesthetics Flashcards
The effects of Adrenaline:
Receptors affected: α1 β1 β2
Inotropic
Chronotropic
Vasopressor
The effects of dobutamaine:
Receptors affected: β1 β2
Inotropic
Chronotropic
The effects of Noradenaline:
Receptors affected: α1 β1
Inotropic
Vasopressor
The effects of Phenylephrine:
Receptors affected: α1
Vasopressor
How are patients on ICU sedated?
A continuous intravenous infusion of Propofol
What can insufficient sedation of a patient on ICU lead to?
Agitation and poor ventilation
What can over sedation of a patient on ICU increase the risk of?
Chest infection
Neuropathies
Venous thromboembolism
What urine output indicated a developing AKI?
less than 0.5ml/kg/hour
Stop which drugs during an AKI?
Stop the DAMN drugs
Diuretics
ACEs and ARBs
Metformin
NSAIDs
What are the target saturations for a COPD patient?
88-92%
What type of respiratory support may be indicated for worsening Type 1 respiratory failure?
CPAP
What type of respiratory support may be indicated for worsening Type 2 respiratory failure?
BiPAP
What may be indicated if non invasive ventilation methods fail?
Intermittent positive-pressure ventilation (IPPV)
What is the safe dose of Lignocaine without adrenaline?
3mg/kg
What is the safe dose of Lignocaine with adrenaline?
7mg/kg
What is the safe dose of Bupivacaine / levobupivacaine ? (with or without adrenaline)
2mg/kg
What is the safe dose of Prilocaine?
6mg/kg
What are the fasting guidelines for clear fluids?
e.g. water, black tea, black coffee, fruit juice without pulp
2 hours
What are the fasting guidelines for breast milk?
4 hours
What are the fasting guidelines for cows milk or a light meal?
6 hours
What drugs are traditionally used in a Rapid Sequence Induction?
Thiopentone (4-5mg/kg)
Suxamethonium (1-1.5mg/kg)
What should a General Anaesthesia achieve?
Amnesia – lack of response and recall to noxious stimuli
Analgesia – pain relief
Akinesis – immobilisation / paralysis
Name 4 induction agents
Thiopentone
Propofol
Ketamine
Etomidate
What are the properties of Propofol and its benefits as an induction agent?
Propofol 1.5 – 2.5 mg/kg
Lipid based (white emulsion)
Excellent suppression of airway reflexes
Decreases incidence of PONV
What are the problems with Propofol as an induction agent?
Propofol 1.5 -2.5 mg/kg
Unwanted effects:
Marked drop in HR and BP
Pain on injection
Involuntary movements
What are the properties of Thiopentone and its benefits as an induction agent?
Thiopentone 4–5 mg/kg
Barbiturate - Faster than propofol
Used mainly for rapid sequence induction
Antiepileptic properties and protects brain
What are the problems with Thiopentone as an induction agent?
Thiopentone 4-5 mg/kg
Unwanted effects: Drops BP but rise in HR Histamine release = Rash / Bronchospasm Intraarterial injection: thrombosis and gangrene Contraindicated in Porphyria
What are the properties of Ketamine and its benefits as an induction agent?
Ketamine 1-1.5 mg/kg Dissociative anaesthesia Anterograde amnesia and profound analgesia Slow onset (90 seconds) Rise in both HR and BP Bronchodilation
What are the problems with Ketamine as an induction agent?
Ketamine 1-1.5 mg/kg
Nausea and vomiting
Emergence phenomenon: vivid dreams, hallucinations
What are the properties of Etomidate and its benefits as an induction agent?
Etomidate 0.3 mg/kg
Rapid onset
Hemodynamic stability
Lowest incidence of hypersensitivity reaction
What are the problems with Etomidate as an induction agent?
Adreno-cortical suppression
Pain on injection
Spontaneous movements
High incidence PONV
A patient with porphyria comes for an inguinal hernia repair
which induction agent do you use?
which do you definitely not use?
Use propofol
Avoid thiopentone
Which induction agent is best used for changing burns dressings?
Ketamine
A patient with intestinal obstruction requires an emergency laparotomy, which induction agent do you use?
Thiopentone
A patient with a history of heart failure requires a general anaesthetic, which induction agent do you use?
Etomidate
Which induction agent can cause adrenal-cortical suppression?
Etomidate
Name the 5 common inhalation agents and consider their MACs
Nitrous oxide: 104% Sevoflurane: 2% Isoflurane : 1.15% Desflurane : 6% Enflurane : 1.6 %
Which inhalation agent can be used for a gas induction in children with no IV access?
Sevoflurane
Which inhalation agent will be used for a long operation lasting several hours?
Desflurane
Which induction agent would be used during an organ retrieval from a donor?
Isoflurane
How do you assess and manage a patient with postoperative pain?
ABCDE assessment
Pain assessment (0-3 score)
Analgesic ladder
Acute pain service
Analgesics for a postoperative pain score of 0
PRN - Paracetamol
Analgesics for a postoperative pain score of 1
Regular- Paracetamol
PRN - NSAID, Weak Opioid
Analgesics for a postoperative pain score of 2
Regular - Paracetamol, NSAID and Weak Opioid
PRN - Strong Opioid
Analgesics for a postoperative pain score of 3
Regular - Paracetamol and NSAID
PRN - Strong opioid
or Standard PCAS, Epidural or Spinal
What is the definition of chronic pain?
Persistent and intractable pain lasting more than 3 months
Diclofenac, Ketorolac and Parecoxib are example of what?
IV NSAIDs
Which opioid is commonly used during induction?
Fentanyl
What are the properties of suxamethonium and what are its benefits?
Suxamethonium 1 -1.5 mg/kg
Depolarising muscle relaxant
- agonist of nicotinic receptors
Rapid Sequence Induction (Rapid onset - Rapid offset)
What are the adverse affects of suxamethonium?
muscle pains, fasciculations, hyperkalemia malignant hyperthermia, rise in ICP, IOP and gastric pressure
What are the short acting non depolarising muscle relaxants?
Atracurium, Mivacurium
What are the intermediate acting non depolarising muscle relaxants?
Vecuronium, Rocuronium
What are the long acting non depolarising muscle relaxants?
Pancuronium
What drugs can be used to reverse non depolarising muscle relaxants?
Neostigmine & Glycopyrrolate
What are the mechanism of action of neostigmine and glycopyrrolate?
Used for reversal of non depolarising muscle relaxants
Neostigmine is an anti-cholinesterase
Prevents breakdown of acetylcholine
Muscarinic effects of acetylcholine = Bradycardia etc
Glycopyrrolate is an antimuscarinic
Reduces unwanted effects of neostigmine
Best vasoactive agent for a patient with a low BP and a low HR?
Ephedrine
Raises BP and HR
Best vasoactive agent for a patient with a low BP and a high HR?
Phenylephrine or Metaraminol
Raise the BP by vasoconstriction
How do you manage a local anaesthetic overdose?
Stop local anaesthetic
ABCDE assessment and management
Control seizures
Give IV Lipid emulsion
