Anaesthetics Flashcards
two many categories of anaesthesia
- General anaesthesia – making the patient unconscious
- Regional anaesthesia – blocking feeling to an isolated area of the body (e.g., a limb)
triad of general anaesthesia
- Hypnosis
- Muscle relaxation
- Analgesia
since general anaesthesia involves patients becoming unconscious, patients must be
intubated or have a supraglottic airway device, and their breathing will be supported and controlled by a ventilator
- Defintiibe airway- endotracheal tube
- for high risk and long surgery
- Supraglottic airway
- most common
before general anesthesia is given patients are
pre-oxygenated
aim: replace nitrogen in the RBC with oxygen
Before being put under a general anaesthetic, the patient will have a period of several minutes where they breathe 100% oxygen. This gives them a reserve of oxygen for the period between when they lose consciousness and are successfully intubated and ventilated (in case the anaesthetist has difficulty establishing the airway)
medication which may be given before patient is put under to relax them and reduce anxiety, pain and make intubation easier
- Benzodiazepines (e.g., midazolam) to relax the muscles and reduce anxiety (also causes amnesia)
- Opiates (e.g., fentanyl) to reduce pain and reduce the hypertensive response to the laryngoscope
what is the idea behind rapid sequence induction/intuvation
successful intubation with an endotracheal tube as soon as possible after induction (when the patient is unconscious) to protect the airway.
biggest concern during rapid sequence induction/intubation
- aspiration of stomach content into the lung
hypnotic agents help which which part of the triad of general anaesthesia
hypnosis
induction agents for general anaesthesia can either be
intravenous or inhaled
intravenous options for GA
- Propofol (the most commonly used)
- Ketamine
- Thiopental sodium (less common)
inhaled options for GA
- Sevoflurane (the most commonly used)
- Desflurane (less favourable as bad for the environment)
- Isoflurane (very rarely used)
- Nitrous oxide (combined with other anaesthetic medications – may be used for gas induction in children)
what type of agents are sevoflurane, desflurance and isoflurane
volatile anaesthetic agents
- must be vaporised into a gas to be inhaled
types of maintenance of GA
- induction: IV and maintenance: inhaled
- induction: IV and maintenance : IV (total intravenous anaesthesia)
total intravenous anaesthesia
IV medication for induction and maintenace of GA
e.g. propofol
benefit of TIVA
nicer recovery when waking up than inhaled options