Upper Airway Management During Anaesthesia Flashcards
Division of upper from lower airway:
Point of division is at the larynx larynx is still part of URT!
How to overcome UAO induced by anaesthesia:
UAO = Upper Airway Obstruction
Maintain patency!
- Simple manoeuvres: Chin lift, jaw thrust, neck extension
- Simple Tools: Oro- ± nasopharyngeal airway
- Intermediate Tools: Supraglottic “laryngeal mask” airway
Laryngeal mask airway (LMA):
- Very good to use!
- Sits posteriorly over the larynx & takes all airway obstruction away
- Bypasses all upper airway structures by pushing the soft tissue aside Simple manoeuvres
Chin lift, jaw thrust, neck extension Simple tools
Oro- ± nasopharyngeal airway Intermediate tools
Supraglottic “laryngeal mask” airway - Has a brilliant seal > can be used for spontaneous breathing or for IPPV
Criteria for using the assisted breathing devices over intubation
- It is a “short procedure” (30 – 90 mins)
- If used for too long = pressure on supraglottic nerves, oedema, & swelling - There is “no” risk of aspiration
- Patients that are NPO
- Usually the last option if there is an aspiration risk but can ventilate / intubate - Body cavity not opened
Murphy tip & eye in intubation
if the distal part is obstructed then the gas can go through the alternative hole
Size of Endotracheal tube in children
Age/4 + 4mm
used in children >2yrs old
Insertion procedure of ET Tube
- Anaesthetise patients
- Use neuromuscular junction blocker
- Use the laryngoscope to create a straight line of vision to see the larynx
- Patient will be apnoeic during this time .. try no more than three times do not take more than 30 – 60 seconds
Disproportion:
one of the most common causes of difficult airway / intubation
If the tongue is too large and the jaw is too small
difficultly in visualizing the larynx
In disproportion, you need to ‘get around the corner’. This is better achieved with curved video laryngoscopy than rigid laryngoscope.
Things making for a difficult intubation
- Can’t open mouth : TMJ disease, ankylosing spondylitis, RA, Still’s disease
- Obesity
- Micrognathia
- Macroglossia
Full list of equipment needed for endotracheal intubation:
- Laryngoscope handle x2
- Laryngoscope blades of different sizes & types
- Endotracheal tube, and another one that is one size smaller, cuffs checked
- Introducer
- Suction
- Drugs for creating good intubating conditions anaesthesia, relaxant, emergency medications
- Face masks
- Oropharyngeal ± nasopharyngeal airways
- Source of oxygen
- Means of applying positive pressure ventilation
7-10 for treating apnea
Correct position of the ET Tube
- Mid trachea
- Below the vocal cords
NB!
not in oesophagus, bronchus, pharynx
Confirmation of correct ETT placement:
- auscultation
- visualization chest mv
- spirometry
- saturation
- CXR
Reasons for using tracheal intubation:
- Maintains a perfectly patent airway
- Facilitates ventilation
- Protects against aspiration
- Facilitates access to the airway to suction secretions, blood etc.
- Anaesthesia / surgical indications:
o Long procedures
o Open body cavities
o Non-supine positions that preclude manual airway support
Mallampathi score
how much tongue tissue there is relative to pharyngeal space
Evaluate the size of the base of the tongue relative to the pharyngeal space
o Class 1 can see soft palate, uvula, & tonsillar pillars
o Class 2 can only see soft palate & uvula
o Class 3 can only see soft palate
o Class 4 see no structures
Cormack & Lehane laryngoscopy view score
- Grade 1 whole larynx visible
- Grade 2 larynx partially visible
- Grade 3 only tip of epiglottis visible
- Grade 4 no airway structures visible
Thyromental distance
- TMD > 6.5 cm predicts that the mandibular space into which tongue & submandibular tissue is compressed or shifted, is large enough so that larynx will be seen using a rigid laryngoscope
Upper lip bite test
- Class 1 the lower incisors can reach and bite above the vermilion border of the upper lip
- Class 2 the lower incisors can reach and bite the vermilion border of the upper lip
- Class 3 the subjects are unable to bite the top lip
Class 1 or 2 predicts easy laryngoscopy, while class 3 predicts difficult laryngoscopy with even greater accuracy than the Mallampathi score
The DAM-IT algorith with intubation
D – Difficult airway anticipated
- Assess the airway (e.g., LEMON criteria)
- Prepare airway equipment and backup plans (video laryngoscope, bougie, supraglottic airway, surgical airway kit)
A – Ask for help
- Call for senior/anesthetist/support staff early
- Ensure roles are clearly assigned
M – Maximize oxygenation
- Pre-oxygenate with 100% O₂ (e.g., non-rebreather or bag-valve-mask with PEEP)
- Consider apneic oxygenation (e.g., nasal cannula)
I – Intubation attempt
- First attempt by the most experienced provider
- Use best technique (e.g., video laryngoscope, proper positioning, appropriate blade size)
- Limit to <30 seconds per attempt
T – Try an alternative
If first attempt fails:
- Use different technique/device (e.g., bougie, second-generation supraglottic airway)
- Reoxygenate between attempts
- If multiple attempts fail, consider emergency front-of-neck access (eFONA or surgical airway)
