Anesthetics Conduct Flashcards
Define 1 “arm-brain” circulation?
The time it takes for an IV GA injected into the arm to reach the brain. ~20s
What are “Planes” of anaesthesia?
1) Sedation
2) Excitation
3) Anaesthesia (Light->Deep)
IV goes so fast you don’t notice them
Inhalational, the patient passes through these planes
What do we use to monitor a patient’s conscious level during Induction?
Verbal contact Movement Resp Pattern EEG "Planes"
In order of “seriousness”, what are the types of airway maintenance?
1) Triple airway manoeuvre
2) Face mask
3) Oropharyngeal (Guedel) airway
4) Laryngeal mask airway
What’s involved in the Triple Airway Manoeuvre?
Head Tilt
Chin lift
Jaw Thrust
What is a Laryngeal mask airway?
A cuffed tube with a mask that sits over the glottis.
It maintains but does NOT protect the airways.
What complications could occur during induction of anesthesia?
Obstruction
Aspiration
What could cause airway obstruction under anesthesia?
- Ineffective Triple Airway Maneouvre
- Airway device malposition/kinking
- Laryngospasm: forced reflex adduction the vocal cords.
Why might patient’s aspirate under anesthesia?
- They lose protective airway reflexes like gag, swallow and cough
- Foreign material like gastric contents, blood and surgical debris
Define airway Maintenance and airway Protection?
A Maintained airway is open & unobstructed
A protected airway is protected from contamination. Only endotracheal intubation will do this
What is endotracheal intubation?
A cuffed tube is placed in the trachea via the oral route using a laryngoscope, muscle relaxant and “sniffing the air” position
- it is possible to keep the patient awake by using local anaestesia and fibre-optic scope.
Why do we need muscle relaxant in endotracheal intubation?
To abolish the laryngeal reflexes
Why would you choose to intubate a patient?
1) Protects from gastric contents in unfasted (emergency) patients
2) For ventilation when using muscle relaxants
3) If there’s risk of blood contamination e.g. tonsilectomy
4) When needing to tightly control blood gasses e.g. neurosurgery
5) When there will be restricted airway access e.g. Maxfax
What parameters can we measure to monitor a patient under anaesthesia?
-SpO2, ECG, NIBP, FiO2 & ETCO2
-Resp parameters
Agent Monitoring
-Temp, urine output and NMJ
-Invasive venous/arterial monitoring
-Processed EEG
What common problems occur during recovery?
A,B & C problems
Pain
N & V
What are the major risks to a patient during anesthesia?
- Airway problems
- Temperature (too cold or too hot)
- Loss of other protective reflexes e.g. corneal can cause injury
- VTE
- Consent/ID
- Pressure areas
What are the major types of LA blocks?
Spinal
Epidural
Plexus block
Nerve block
What is the process of anaesthesia? (7 steps)
- Pre-operative Assessment
- Preparation
- Induction
- Maintenance e.g. with general anaesthesia
- Emergence
- Recovery
- Post-operative Care and Pain Management
what are some of the most common drugs used in IV induction?
Propofol- safe, predictable
Thiopentone
what is the most common inhalation drug
Sevoflurane (Halothane)
when is gas induction used commonly?
more common in younger children as they are more nervous/ difficult about IV infusion.
Features of gas inhalation?
- SLOW: takes time for the drug to be absorbed
- more obvious planes of anaesthesia
Oropharyngeal airway
- Rigid plastic
- Only tolerated by an unconscious patient
- insertion in a light patient (wakes up easily) may cause vomiting/laryngospasm
What occurs during awakening?
- muscle relaxation reversed
- anaesthtic agents off
- resumption of spontaneous respiration
- return of airway reflexes
- extubation
- can be very quick or very slow
