ANAESTHETICS Flashcards
Broadly, what are the two types of airway management?
Simple airway
Advanced airway
Describe how a simple airway is maintained.
- Airway manoeuvre
- BVM
- OP/NP tube
Name two types of airway manoeuvre. What is the aim of airway manoeuvres?
Head tilt, chin lift
Jaw thrust
To lift the tongue and soft tissues of the pharynx anteriorly to open the airway.
When should you use a jaw thrust manoeuvre instead of head tilt?
Suspected trauma.
What is BMV?
Bag-mask-ventilation.
Facemask is used.
Which two airways can be used to aid BMV?
Oropharyngeal (OP) (guedel)
Nasopharyngeal (NP)
How do you insert an OP airway?
- Measure from the centre of the mouth to the angle of the jaw
- Insert into mouth and twist to advance
DO NOT USE IF GAG REFLEX PRESENT
How do you insert a NP airway?
- Measure from the tip of the nose to the tragus of the ear
- Through the nose
- Advance straight
DO NOT USE IN HEAD INJURY
Name two supraglottic airways?
LMA
iGel
How do you insert an LMA?
Insert blind
Inflate mask once situated
How do you insert an ET tube?
- Visualise with laryngoscope
- Sizing: 7 for women, 8 for men
- Inflate cuff to protect the airway
- 20-24cm markings should lie between the teeth
- Used in theatre and ICU
Elastic bougies can be used to aid ET tube placement.
How do you insert a tracheostomy?
• Needle (emergency) or surgical cricothyroidotomy
• Inserted from front of the neck
• Cuff to protect airway
Used in ITU
Which interventions protect the airway?
ET
Fibreoptic intubation
Cricothyroidotomy
What is a definitive airway?
Cuffed tube below the vocal cords to create a seal and prevent aspiration.
ET tube or tracheostomy.
(NOT LMA as this may not protect the airway and there is still risk of gastric aspiration).
Broadly, what are the two types of ventilation?
Non-invasive airway (NIV)
Invasive airway
When do we use NIV?
When supplemental O2 is failing e.g. respiratory failure.
What are the two types of NIV?
CPAP
BiPAP
How do we decide which type of NIV to use?
Depends on the type of respiratory failure.
Type I = CPAP
Type II = BiPAP
How does CPAP work?
Maintains a minimum airway pressure.
In alveolar collapse (pneumonia) –> keeps alveoli open
In pulmonary oedema (heart failure) –> pushes the fluid out
How does BiPAP work?
During inspiration, BiPAP gives extra IPAP (inspiratory positive pressure).
Increases lung expansion and ventilation.
AND during expiration, maintains minimum airway pressure with EPAP (same as CPAP):
Keeps alveoli open and pushes fluid out.
Give two examples of invasive ventilation.
ET tube.
Tracheostomy.
What two types of ventilation can be achieved with invasive management?
- Volume control - theatres.
2. Pressure control - theatres and ITU, protects lungs from too much pressure (ITU/children).
How does invasive ventilation work in terms of volume-control and pressure-control?
Volume-control:
- Pressure increases
- Target volume reached
- Ventilator stops
- Expiration occurs
Pressure-control:
- Pressure constant
- Target time reached
- Ventilator stops
- Expiration occurs
What is FiO2?
Fraction of inspired O2.
Molar/volumetric content of O2 in an inhaled gas.