Airway assessment and management - Anaesthetics Flashcards
Airway assessment
Identify predictable problems with the maintenance of oxygenation during airway management and to formulate an airway plan in the event of the unexpected difficult airway or emergency airway management.
- body habitus and obesity
- characteristics of the neck
- shortness or a lack of mobility
- characteristics of the jaw, including a receding jaw or limited ability to open the mouth and dentition of lose or protruding teeth.
Components of airway assessment (PPPBMMTUTC)
- Previous hx of previous anaesthesia issues including difficult intubation
- Presence of gastroesophageal reflux
Presence of obstructive sleep apnoea - BMI
- Mouth opening and interincisor gap (IIG)
- Modified Mallampati score
- Teeth examination
- Upper lip bite test (ULBT)/ 8. Mandible protrusion test
- Thyromental distance (TMD)
- Cervical spine movement
Mallampati Score
A simple scoring system relating to the amount of mouth opening to the size of the tongue and provides an estimate of space available for oral intubation by direct laryngoscopy.
Thyromental distance
Used to estimate mandibular space
Simplified Airway Risk Index Assessment (SARI)
Multivariate risk score for predicting difficult tracheal intubation.
- Combines the criteria as set out by the ANZCA.
- Score ranges from 0-12
- E.g., SARI score of 4+ indicates difficult intubation.
Factors affecting airway choice:
- Age
- Type of procedure, including pt positioning
- Length of procedure
- Medical condition
- Fasting status of pt
- Type of anaesthetic being administered
Face mask
Rubber or silicone masks that cover the mouth and nose of the pt.
- Used to deliver 02, N20-02 and other inhalation agents.
Oropharyngeal airway
Also known as a Guedel.
- Flat section rests on tongue, preventing it from falling into the pharynx and resulting in obstruction.
- Size must be large enough to go beyond the back of the tongue, but shouldn’t press on the posterior pharyngeal wall since this may stimulate the gag reflex.
Nasopharyngeal Airway
Used when a oropharyngeal airway is contraindicated.
- Traumatic and can cause bleeding and swelling if incorrectly inserted.
Laryngeal mask airway (LMA)
Designed to be left in place until the return of the protective reflexes of the airway such as the gag reflex.
- Used to provide supplemental oxygen via a T-piece system or a Bain’s circuit.
- Device of choice for supraglottic airway ventilation.
Factors affecting difficult supraglottic airway:
- restricted mouth opening
- stiff cervical spine
- upper airway obstuction
Proseal LMA
A LMA incorporating a second tube lateral to the airway tube.
- Second tube is intended to separate the alimentary and respiratory tracts.
- Permits access to or escape of fluids from the stomach and reduces the risk of gastric insufflation and pulmonary aspiration.
Supreme LMA
Differs from a standard LMA as it has two seals.
- First is the oropharyngeal seal
- Second is an upper oesophageal sphincter seal.
- Second seal is important as it minimises gastric insufflation and reduces the risk of aspiration.
LMA Fastrach
Specifically designed to improve blind and endotracheal intubation through a LMA.
- Useful in difficult intubation cases on their own or in conjunction with the fibreoptic-intubating laryngoscope.
Endotracheal tubes (ETT)
Placed between the vocal cords through the trachea.
- Serves to provide oxygen and inhaled gases to the lungs
- Protects lungs from contamination - including gastric contents and blood.
