Airway management and equipment Flashcards
1
Q
Why do anaesthetists consider the airway as a separate system?
A
Their specialty involves the manipulation of airway through the use of endotracheal tubes and other airway devices and the agents used to affect the airway in various ways. And they have to take over the patient’s role to protect their airways.
2
Q
Should the airway only be assessed when general anaesthesia is given?
A
Wrong: Anything can happen and the regional/local anaesthetic can fail and you will have to intubate.
3
Q
Name a factor that causes difficulty for both BVM and intubation
A
Obesity and obstruction
4
Q
State three causes of airway distortion.
A
Airway trauma
Epiglottitis
Laryngeal tumours
5
Q
State three causes of immobility of neck that affect intubation and BVM.
A
Cervical spine injury
Fixed cervical spin or decreased extension
Limited mouth opening
6
Q
Outline the Mallampati airway classification
A
Class I = visualisation of the soft palate, fauces, whole uvula, anterior and posterior pillars
Class II = visualisation of the soft palate, fauces and most of the uvula
Class III = visualisation of the soft palate and only the base of the uvula
Class IV = only hard palate visible, soft palate is not visible at all
7
Q
Name three bedside tents used to predict difficult intubation
A
Distances: Thyromental, inter incisor, thyrohyoid
Mallampati airway classification
Neck mobility
Note: In isolation, each test has a poor predictive value, but when used in combination, there
is a good probability that no surprises will be found at laryngoscopy
8
Q
List the 4 Ds of airway assessment
A
Disproportion
Distortion
Dysmobility
Dentition
9
Q
List 5 causes of disproportion of the airway.
A
Macroglossia
Micrognathia
High arched palate
Bony abnormalities
Short thick neck
10
Q
List 5 factors that make laryngoscope and intubation difficult.
A
Absence of teeth
Passion gap(Gap between upper teeth)
Protruding teeth (Buck teeth)
Loose teeths
Having dental work that could be injured with laryngoscopy such as caps and crowns.
11
Q
List 4 things to look for when assessing the face.
A
Overt tumours
Congenital syndromes
Facial trauma
Facial hair
12
Q
List 6 things to look for when assessing the mouth
A
Mouth opening
Macroglossia
Tumours, trauma and other masses
Mallampati airway classification
Dentition
13
Q
List 5 things to look for when assessing the neck
A
C spine injury
Length and thickness of neck
Range of movement(Both extension and flexion)
Thyro-mental and sterno mental distances
Tracheal position
14
Q
Outline 4 historical information that should be established before airway management.
A
Previous anaesthetic history(check the record if available)
History of congenital, acquired or traumatic pathology
Previous head and neck surgery
Previous radiotherapy of the airway area and head
15
Q
A
16
Q
Is the assessment of the airway necessary when the surgery is an emergency?
A
Always and always and always important
17
Q
State the four principles/major problems encountered in airway management.
A
Difficulty ventilating or oxygenating the patient
Difficulty intubating the patient
Difficult placing a supraglottic(Rescue airway after intubation fails)
Difficult to gain front of neck access(surgical airway)
18
Q
5 predictors of bag mask ventilation difficulty.
A
Mask seal problems(beards and tubes), Obesity/obstruction, Advanced age, No teeth(edentalous), stiff lungs.
19
Q
A
20
Q
4 predictors of difficulty supraglottic
A
Restricted mouth opening, Obstruction and obesity, Distorted airways/dsymorphic anatomy, stiff neck and lungs(bronchospasm)
21
Q
List 6 predictors of difficult front of neck access
A
Scars or surgery of neck
Hematoma(bleeding in neck)
Obstruction/obesity
Radiotherapy of neck
Trauma or tumours of the anterior neck
Very young patients
22
Q
List 5 predictors of difficult intubation
A
Look externally
Evaluate the 332: Thyro-mental, interincisal and thyrohyoid distances
Mallampati airway classification
Obstruction and obesity
Neck mobility
Other is the 4Ds
23
Q
State the most important but commonly missed information from history that is essential in airway management
A
History of head and neck surgery or radiotherapy
24
Q
Name a tool used for a thorough airway exam.
A
4 Ds mneumonic: Usually done after a targeted exam using the other tools such as LEMON
25
What is the Thyromental distance that is predictive of a difficult intubation?
<3 finger breadths or <6 cm in adults
Remember: It is measured when the neck is fully extended
26
What is the inter incisor distance predictive of difficult intubation?
<3 finger breadths or <4 cm in adults
Remember: Ask the patient to open their mouth as wide as possible.
27
What is the thyrohyoid distance predictive of difficult intubation?
<2 finger breadths or <3-4 cm in adults
Remember:This measurement is performed with the patient's neck in the neutral position.
28
What is the perfect position to perform the mallampati test?
The patient must be in a sitting position with his head held in a neutral position
29
Should patient phonate when assessing the Mallampati score?
Nope, but saying aah provide an indication of tissue mobility
30
Which joint is responsible for neck mobility?
Atlanto occipital joint
31
State how the Atlanto occupational joint mobility can be assessed.
Place one finger on the mentum (under the chin) and one on the occiput; the head is gently extended. The inability to lift the finger on the mentum above that on the occiput indicates limitation of neck extension.
Note: The head is held erect and facing forward
32
Name all important equipment for airway management.
• Introducer (bougie or stylet to guide the tube)
• Masks and Magill’s forceps
• Airways (oral/Guedel, nasal, and supraglottic/LMA) and Ambubag (self-inflating
resuscitator)
• Laryngoscopes (several blade sizes, at least two handles, and check the lights!)
• Endotracheal tubes (appropriate range of sizes)
• Suction (check that it is working and reaches the bed)
33
Name two most essential monitors for safe
airway management
Capnography and pulse oximetry
34
List routine monitors used in airway management
Capnography, pulse oximetry, non invasive BP monitoring, Three lead EKG
35
Name three groups of drugs that are a must for airway management
• Induction agent – a rapidly acting anaesthetic such as propofol, ketamine or
etomidate
• Neuromuscular blocker – rapid-acting drugs such as succinylcholine or rocuronium
available
• Inotrope/Vasopressor – for management of post-intubation hypotension. Usually
ephedrine.
36
State two most important patient preparation factors in airway management.
Positioning and preoxygenation
37
What is the ideal position for airway management?
Sniffing position: flexion of the cervical spine with
extension of the atlanto-occipital joint, which straightens the airway and reduces soft tissue
obstruction
38
How do you confirm the patient is placed in a sniffing position?
Can be identified by the external auditory
meatus and sternal notch being in the same plane, with the patient’s face parallel to the ceiling
(ear-to-sternal-notch or “E2SN”):
39
How long can a healthy person undergo apnea after adequate preoxygenation?
Up to 8 minutes
40
State how patients are preoxygenates.
A snug fitting face mask is placed on a patient and high flow oxygen(80-100% Oxygen) is given for 2-
3 minutes
41
What is considered sufficient preoxygenation in emergencies?
6-8 large (vital capacity) breaths, or waiting for end-tidal O2 to exceed 80%
42
5 indications for a surgical airway
1.Prolonged ventilation in ICU
2.Head and neck deformity / trauma
3.The “impossible intubation”
4.Difficult weaning from ventilation
5.Emergency rescue airway
43
State two types of surgical airways
Emergency cricothyroidotomy
Tracheostomy
44
List 3 tools needed to perform a cricothyroidotomy.
Needles
Kit(Minitrach)
Surgical
For tracheostomy: Percutaneous and surgical
45
What is the incidence of unexpected difficult intubation?
1:3000
46
List 4 options available if difficult intubation is anticipated.
Options include to intubating awake (such as using a flexible scope); doing gas induction,
keeping the patient breathing while you intubate and then only paralyse once the airway is secure
(if necessary); or using advanced tools like videolaryngoscopy.
Note: Never induce anaesthesia in these instances without a good plan
47
Is it an immediate emergency if you can mask ventilate but not intubate?
Nope, as you are able to oxygenate the patient.
48
State what should be done in order if you can ventilate the patient but not intubate the patient.
Get help, make a plan, or wake the patient up and reconsider your options. Can consider Supraglottics
49
Name a life threatening emergency in airway management.
can’t intubate, can’t oxygenate” (CICO)
50
What is the excellent resource device for patients who can be mask ventilated but not intubated?
Supraglottics
51
List 5 advantages of supraglottic airways.
• Easy to insert with high success rate, even in relative novice hands
• Less stimulating than intubation
• Lower incidence of sore throat than following intubation
• Relieves an anaesthetist’s hands to control the anaesthetic and make notes, etc.
• Can often ventilate the patient, provided relatively low pressures (< 20 hPa (cmH20)) are
used
52
List 3 disadvantages of supraglottic airways.
• Older models offer no protection of the airway from aspiration, although the newer devices can
• Ventilation not always possible with this device, particularly needing high airway pressures
• Laryngospasm may occur with the use of this device, particularly if the patient is in a light
plane of anaesthesia.
53
State why the 2nd generation supraglottics are better than first generation.
2nd generation and later – such as the Proseal® LMA – which have gastric drainage channels
54
Are all supraglottic airways the laryngeal mask airway?
Nope, just a misnomer
Note: this happens due to the popularity of the original LMA by Dr Archie Brain (UK) in the 1980s
55
Why are the supraglottic airways used now in approximately 60% of general anaesthesia cases worldwide
They are easy to use and they are replacing the facemask anaesthetic.
56
State 3 indications of supraglottic airways.
• Primary strategy: Properly fasted patients without gastro-oesophageal reflux for surgical procedures of short to moderate duration (up to around 2 hours).
• Rescue strategy: Recommended “Plan B” in cases of failed intubation, or where they are used deliberately as a conduit to assist intubation in a difficult airway using a flexible scope.
• Resuscitation: Use during CPR to avoid interruptions in chest compressions for
intubation.
57
What guides the size of a supraglottic airway to be used.
Lean body mass
Note: Some devices use the patient height
58
What is the preferred size of supraglottic for patients who weigh 50-70kg?
Size 4
59
What is the preferred size of supraglottic for adult females?
Size 3 or 4
60
What is the preferred size of supraglottic for adult males?
Size 4 or 5
61
Name two maneuvers used to open the airway.
1. Extend the head at the atlanto-occipital joint: A head-tilt & chin-lift.
2. Then attempt a jaw-thrust, by lifting the jaw forward.
If ineffective: an oropharyngeal (Guedel) or nasopharyngeal airway may be used.
62
63
In a spontaneously breathing patient, effective mask ventilation may be determined by:
• Visually inspecting the chest for good expansion during inspiration
• Absence of accessory muscle use and tracheal tug
• Inspection of the reservoir bag of the breathing circuit to obtain an indication of the tidal
volume
• Observing a square waveform tracing on the capnograph on the monitor
64
Signs of upper airway obstruction
snoring or stridor, tracheal tug and
accessory muscle use.
65
Name a common sign of upper airway obstruction that newbies miss.
a “see-saw” movement of the abdomen and chest
66
What does silent airway drung respiratory effector indicate?
Complete obstruction
Note: It may lead to negative pressure pulmonary
oedema
67
68
Name a complication of severe or complete upper airway obstruction and state how you manage it.
Negative pressure pulmonary oedema:
Management: Re intubation and ventilation in intensive care
Note: Usually occurs in fit, strong and healthy individuals
69
4 advantages of tracheal intubation
- A direct and sealed airway conduit for ventilation
- Protection from aspiration of gastric contents
- Ability to provide effective positive pressure ventilation
- Ability to clear secretions from the respiratory tract by suctioning
70
3 disadvantages of tracheal intubation
- Usually requires induction of anaesthesia and muscle relaxation to accomplish
- Prolonged intubation attempts can lead to hypoxia, brady- or tachycardia, hypo- or
hypertension
- Risk of trauma to the airway during intubation, or from overinflated tracheal tube cuffs
71
List 4 indications of intubation
1. Controlled ventilation. Gold standard means of isolating the trachea & bronchial tree
2. Protection of the airway. A cuffed endotracheal tube provides a measure of protection
from the aspiration of gastric contents and allows effective tracheo-bronchial suctioning
3. Maintenance of a patent airway:
4. Postoperative ventilation in intensive care
72
Name 4 instances where intubation is required for the maintenance of the airway.
a. Unusual intra-operative position, e.g. prone
b. Airway is inaccessible, e.g. head and neck operations
c. Surgeon and anaesthetist are competing for the same area, e.g. ENT surgery
d. Difficulties with facemask / LMA are anticipated, e.g. grossly obese
73
When was tracheal intubation first described in humans and what was it's first used?
1788
Used for resuscitation of victims of drowning
74
What is the gold standard for providing secure airway?
Tracheal intubation
Also required for safe completion of many surgical procedures
75
Name two types of laryngoscope blades.
A curved Macintosh blade and the straight miller or magill blade
76
What is the common place to find uncuffed Endotracheal tubes?
Paediatrics
77
Should cuff pressures measure be done routinely after intubation?
Always and always and always
78
What is the commonly used size of endotracheal tube in adult males and femals
Males: 7,5 - 8,0 mm tube
Females: 7,0 - 7,5 mm
Note: These are for orotracheal tubes, but for nasotracheal intubations, this size is usually reduced by 1,0 or 0,5 mm
79
80
What is the formula to estimate the endotracheal tube size in paediatrics?
(age in years / 4) + 4 [or age / 4 + 3,5 if using a cuffed tube]
Note: Always have a size above and below (0,5 mm) to hand
81
State the Rough guide to depth of ETT
20 ± 2 cm mark at teeth for adult females
22 ± 2 cm mark at teeth for adult males
In children, you can use the formula: (age in years / 2) + 12
Note: An alternative estimation of tube depth is that depth in cm should be approximately 3 times the tube size in mm. (E.g. a 5.0 mm ID tube should be inserted about 15 cm)
82
State two uses of intubating(Magill forceps)
1. Used to guide the tip of the endotracheal tube through the glottic opening (vocal cords)
during a nasotracheal or difficult intubation
2. Used for the placement of a nasogastric tube into the oesophagus under direct vision, placement of a throat pack, or the removal of any foreign body.
Note: It can damage the cuff
83
84
Why should stylet never protrude beyond the endotracheal tube top?
They have a semi rigid structure (made from plastic covered malleable metals) thus they can cause trauma
85
Differentiate the stylet and a bougie
Bougie: Longer >60 cm, softer and flexible and have a slightly bend(elbow) coude tip, can be passed beyond the ETT tip.
Stylet: Shorter, semi rigid and can be bent into an ice hockey stick shape(helps to modify the curve of an ETT), it should not be passed beyond the ETT tip
Both are helpful in difficult intubations
86
What are straight airway exchange catheters?
Long hollow and semi rigid devices used to facilitate the exchange of one airway devices or to manage extubation. They are passed through the existing airway devices and can serve as a conduit for oxygen delivery, monitoring or as a guide for reintubation
87
What is the most common cause of difficult intubation?
Incorrect head positioning
The correct position: The cervical spine is flexed, and only the atlanto-occipital joint extended – “Sniffing the morning air” (ensure the patient’s head is on a pillow)
88
When positioning the patient for intubation, should you extend the head and neck fully?
BIG WRONG . FLEXTENSION IS THE WAY TO GO
89
What is the name of the space between the base of the tongue and epiglottis?
Vallecula
90
What is the best way to confirm the intubation has been placed correctly?
Observing a continuous, square waveform trace on the capnography
Note: Seeing the tube pass through the vocal cords is reassuring, but has been shown to be unreliable (especially for novices) and is only a once-off measure.
91
State way to confirm the ETT tube is placed in the trachea and the limitations of each.
1. Capnography: Only reliable and continuous method
2. Seeing it pass through the cord: Unreliable (especially for novices) and is only a once-off measure.
3. Observing bilateral chest expansion is useful, but unreliable in obese patients or those with lung pathology
4. Auscultation is obligatory, to confirm equal bilateral air entry and exclude endo-bronchial intubation
92
State two limitations of the capnography as a confirmation of correct ETT placement
The trace can look normal if the tube is in one of the bronchi, or if it is in the oropharynx with just the tip between the vocal cords.
Thus: Do not skip auscultation
93
What can be a good replacement of ETT confirmation is a capnography is unavailable?
Disposable CO2 detectors (discs)
Note: They may be of value in emergency intubations, e.g. ambulances, emergency rooms
94
Is misting or the ETT a reliable sign of confirming correct placement of ETT?
Nope WRONG☣️
95
Are chest X-rays useful in the immediate determination of a correct placement
Nope, but are routine for long term intubation
Not reliable, it cannot differentiate tracheal from oesophageal intubation
96
Why are oesophageal detectors not reliable way to confirm tracheal placement?
Can have false positives and negatives
97
State two common areas where nasotracheal intubation is done
Paediatrics
Surgery in the theatre: ENT surgery, dentistry , maxillofacial surgery
98
Is nasotracheal intubation good for long term ventilation in the ICU?
Controversial as it is associated with an increased incidence of sinus infection, but is require secure, generally better tolerated by patients, allows oral cleaning and requires less
sedation.
99
State two things that should be done before nasotracheal tube intubation.
The nostril should be prepared with vasoconstrictor drops (e.g. ephedrine or oxymetazoline) to minimise bleeding and
the ETT is softened in hot water prior to insertion.
Note: Passage through the nose must not be forced!!
100
When is it safest to extubate the patient?
When they are alert, responsive to command and can take deep breaths
101
Why is it not advisable to extubate the patient while they are in a semi conscious state?
Laryngospasm can be triggered
102
When to continue supplementary oxygen after extubation of the patient? State the ideal sats after extubation when breathing room air.
Fi02=<0.4: Continue
Sats>92: Ideal
103
What should you do after extubation if you need > 40 % O2 to maintain the sats at > 90 %?
Call for help, try to identify and correct the cause, and provide airway / ventilatory support
104
Outline 8 complications of intubation
• Trauma to nose, lips, teeth, soft tissues of larynx and airway
• Bronchial intubation from too deep a tube (common)
• Intubation response: Tachycardia, hypertension, dysrhythmias, bronchospasm,increase in intra-cranial and intra-ocular pressure
• Increased resistance to breathing – narrow tube or kinked tube
• Obstruction of endotracheal tube: Collapse, foreign body, secretions, biting,
problems with cuff, bevel of tube against the tracheal wall
• Oesophageal intubation. NO TRACE = WRONG PLACE. If in doubt, take it out!
• Dislodgement into pharynx or bronchus as a result of inadequate securing of the
tube
• Failed intubation
105
Outline 6 complications of intubation
• Laryngospasm.
• Aspiration of gastric contents.
• Hoarseness and sore throat
• Oedema of trachea and larynx
• Ulceration of vocal cords and / or trachea
• Tracheal stenosis after long-term intubation.
106
Outline the management of laryngospasm that occurs after extubation.
Apply O2 via tight fitting facemask with continuous positive airway
pressure (CPAP). If necessary, use a small dose of suxamethonium (25 mg) to reintubate
107
State how aspiration during extubation can be prevented.
Prevented by extubating awake and placing the patient in the left lateral (recovery) position
Note: May occur if you extubate before protective reflexes
have returned (i.e. a deep / asleep extubation)
108
State a complication of extubation that occurs only with prolonged intubation
Ulceration of vocal cords and or trachea
