2. Airway Management Flashcards
(97 cards)
1
Q
airway assessment
A
is mandatory for provision of any anaesthetic, whether general,
regional, local, or ‘only’ sedation. It is also essential before managing the airway, even in
emergency settings.
A targeted history and clinical examination can be supplemented by
special investigations if needed
2
Q
difficult mask mask ventilation
A
can’t oxygenate
3
Q
difficult laryngoscopy or intubation
A
can’t intubate
4
Q
difficult (or impossible) supraglottic
A
can’t rescue
5
Q
difficult front- of neck access
A
can’t fona
6
Q
difficult mask ventilation acronym
A
BONES
7
Q
difficult intubation acronym
A
LEMON
8
Q
Difficult (or impossible) supraglottic acronym
A
RODS
9
Q
difficult front of neck access/ cricothyroidotomy acronym
A
SHORTY
10
Q
Difficult mask ventilation: BONES
A
B- beards
O- obesity/ obstruction
N- no teeth
E- elderly
S- stiff lungs or snoring
11
Q
Difficult Intubation: LEMON
A
L- Look externally (does the airway look difficult?
E -Evaluate the 3-3-2:
**3 fingers thyromental distance
**3 fingers interincisal distance
**2 fingers thyrohyoid distance
M -Mallampati classification
O -Obstructions
N- Neck mobility
(or you can use the “Four D’s”
12
Q
Difficult (or impossible) supraglottic: RODS
A
R Restricted mouth opening
O Obstructions or morbid Obesity
D Distorted or dysmorphic anatomy
S Stiff lungs (e.g. bronchospasm)
13
Q
Difficult front-of-neck access: SHORTY
S Scars or surgery to the neck
H Haematomas (bleeding into the neck)
O Obesity or Obstruction
R Radiotherapy to the neck
T Trauma or tumours of the anterior neck
Y (Very) Young patients
A
S Scars or surgery to the neck
H Haematomas (bleeding into the neck)
O Obesity or Obstruction
R Radiotherapy to the neck
T Trauma or tumours of the anterior neck
Y (Very) Young patients
14
Q
The FOUR D’s pf Airway Assessment
A
disproportion
distortion
dysmobility
dentition
15
Q
disproportion
A
- Macroglossia (big tongue)
- Micrognathia (small chin)
- High arched palate
- Bony abnormalities
- Short thick neck
16
Q
distortion
A
- Airway trauma
- Epiglottitis
- Abnormal larynx (e.g. laryngeal tumours)
17
Q
dysmobility
A
Limited mouth opening (< 3 cm)
- Fixed cervical spine (e.g. ankylosing spondylitis)
- Cervical spine injury
18
Q
dentition
A
- Gap between upper teeth (‘passion’ gap)
- Protruding upper teeth (‘buck’ teeth)
19
Q
Sets of bedside tests sued to predict possibility of a difficult intubation
A
- Thyromental, interincisor and thyrohyoid distances (“3-3-2”)
- Mallampati classification / score
- Neck mobility (extension at the atlanto-occipital joint)
20
Q
Thyromental, interincisor and thyrohyoid distances (“3-3-2”)
A
-Thyromental distance:
The thyromental distance is the distance in the midline from the mentum (chin) to the
thyroid notch. This measurement is performed with the patient’s neck fully extended. A
thyromental distance of < 3 finger-breadths, or < 6 cm in adults, is predictive of a difficult
intubation.
-Interincisor distance:
The interincisor distance is the distance between the incisors when the patient opens
their mouth as widely as possible. A distance of < 3 finger-breadths, or < 4 cm in adults,
is predictive of a difficult intubation.
-Thyrohyoid distance:
The thyrohyoid distance is the distance of the lower mandible in the midline from the
mentum (chin) to the thyroid notch. This measurement is performed with the patient’s
neck in the neutral position. A thyromental distance of < 2 finger-breadths, or < 3-4 cm
in adults, is predictive of a difficult intubation.
21
Q
The Mallampati description
A
This test is performed with the patient in the sitting position, the head held in a neutral position,
the mouth wide open, and the tongue protruding to the maximum. Patients do not phonate when
assessing the Mallampati score, but saying “aaaah” will provide an indication of tissue mobility.
The subsequent classification is assigned based upon the pharyngeal structures that are visible.
22
Q
The Mallampati 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
23
Q
a hoarse voice, stridor or difficulty in phonation
A
suggests difficulty in managecment of the airway
24
Q
neck mobility
A
measure the extension of the antlanto occipital joint
25
Why is preparation crucial for airway management?
Preparation is crucial because airway management demands full attention and quick response to emergencies.
26
What are the three main categories of preparation mentioned?
The three main categories of preparation are -
-equipment,
-drugs (induction and emergency) , and
-patient positioning/preoxygenation.
27
What equipment is essential for airway management?
Essential equipment includes introducers, masks, airways, laryngoscopes, endotracheal tubes, and suction devices.
28
What does the acronym IMALES stand for?
IMALES stands for
-Introducer,
-Masks,
-Airways,
-Laryngoscopes,
-Endotracheal Tubes, and
-Suction.
29
Why is it important to check the equipment before starting airway management?
It's essential to check the equipment to ensure everything is in working order and readily available in case of emergencies.
30
What are the crucial monitors for safe airway management?
The crucial monitors are the capnograph and pulse oximeter.
31
What drugs are necessary for airway management?
induction agents
neuromuscular blockers
inotropes/ vasopressors
32
induction agents
propofol,
ketamine,
etomidate
33
neuromuscular blockers
(succinylcholine,
rocuronium
34
inotropes/vasopressors
usually ephedrine
35
Why is neuromuscular blockade important?
Neuromuscular blockade ensures muscle relaxation, facilitating easier airway management.
36
What is the role of inotropes/vasopressors during airway management?
Inotropes/vasopressors are used to manage post-intubation hypotension.
37
38
What are the two key factors in patient preparation for airway management?
The two key factors are positioning and preoxygenation.
39
Describe the ideal patient position for airway management.
The ideal patient position features flexion of the cervical spine with extension of the atlanto-occipital joint, known as "sniffing" or "flextension" position.
40
How can you identify the correct patient position?
The correct position is identified when the external auditory meatus and sternal notch are in the same plane, with the patient's face parallel to the ceiling (ear-to-sternal-notch or "E2SN").
41
What is preoxygenation?
Preoxygenation is the process of allowing a patient to breathe a high concentration of oxygen (80-100%) before induction and airway management.
42
Why is preoxygenation important before induction and airway management?
It denitrogenates the lungs, leaving more oxygen available for consumption during the apnoeic period and lengthening the time before desaturation occurs.
43
How long can a healthy adult undergo apnoea after adequate preoxygenation?
A healthy adult can undergo up to 8 minutes of apnoea after adequate preoxygenation.
44
What are the potential risks of diminished muscle tone during induction of anaesthesia?
Diminished muscle tone during induction of anaesthesia may cause upper airway obstruction, leading to hypoxaemia, hypoxia, and inadequate ventilation.
45
What basic manoeuvres can be performed to provide a patent airway during facemask ventilation?
Basic manoeuvres include head-tilt & chin-lift followed by a jaw-thrust if necessary.
46
How can effective mask ventilation be determined in a spontaneously breathing patient?
Effective mask ventilation can be determined by:
-visually inspecting chest expansion,
-absence of accessory muscle use,
-inspection of the reservoir bag,
-and observing a square waveform tracing on the capnograph.
47
if you are unable to perform BVM
you can use n oropharyngeal or nasopharyngeal airway
48
What are signs of upper airway obstruction?
Signs include
-snoring or stridor,
-tracheal tug, and
-accessory muscle use.
Complete obstruction may lead to a "see-saw" movement of the abdomen and chest.
49
How can complete upper airway obstruction be identified?
Complete upper airway obstruction may be identified by a silent airway during respiratory efforts.
50
What complications may arise from severe or complete upper airway obstruction?
Complications may include negative pressure pulmonary edema, necessitating re-intubation and ventilation in intensive care, particularly in fit individuals. (it usually occurs in otherwise fit, strong and healthy individuals)
51
When was tracheal intubation first described in humans?
Tracheal intubation was first described in humans in 1788, initially used in the resuscitation of drowning victims.
52
tracheal intubation
it is the gold standard for providing a secure airway and is required for safe completion of many surgical procedures
53
What are the advantages of tracheal intubation?
Advantages include:
-a direct and sealed airway conduit for ventilation
-protection from aspiration of gastric contents,
-ability to provide effective positive pressure ventilation, and
-ability to clear secretions from the respiratory tract by suctioning.
54
What are the disadvantages or risks associated with tracheal intubation?
Disadvantages or risks include:
-the need for induction of anaesthesia and muscle relaxation,
-potential for hypoxia or cardiovascular changes during prolonged attempts, and
-risk of airway trauma.
55
What are the indications for tracheal intubation?
Indications include
-controlled ventilation,
-protection of the airway,
-maintenance of a patent airway in specific surgical scenarios, and
-postoperative ventilation in intensive care.
56
Why is tracheal intubation necessary in certain surgical procedures?
Tracheal intubation is necessary for safe completion of many surgical procedures, particularly those involving:
- unusual intra-operative positions, e.g prone
inaccessible airways e.g. head and neck operations
-or competition between surgeon and anaesthetist (ENT surgery)
- difficulties with facemask/ LMA are anticipated e.g. grossly obese
57
In what scenarios might postoperative ventilation in intensive care require tracheal intubation?
Postoperative ventilation in intensive care may require tracheal intubation for patients who are unable to maintain adequate respiratory function on their own.
58
What equipment is necessary for tracheal intubation?
Necessary equipment includes
-laryngoscopes,
-endotracheal tubes,
-intubating forceps, and
-introducers (such as stylets and bougies).
59
What factors determine the appropriate size of an endotracheal tube?
The appropriate size of an endotracheal tube is determined by the patient's gender and age, with specific formulas used for adults and children. Additionally, depth of insertion is guided by marks on the tube or formulas based on patient characteristics.
60
What materials are commonly used in the construction of Endotracheal Tubes (ETT)?
Endotracheal tubes are typically made from non-toxic, non-irritant plastic materials to ensure patient safety and minimize the risk of allergic reactions or tissue irritation.
61
How does the inflatable cuff contribute to the functionality of an Endotracheal Tube (ETT)?
The inflatable cuff near the tracheal end of an ETT provides an airtight seal between the tube and the trachea, preventing air leakage and aspiration, thus ensuring effective ventilation and patient safety during intubation.
62
How is the inflation of the cuff managed, and why is it important to monitor cuff pressures post-intubation?
The cuff is inflated using a syringe via a separate channel, and cuff pressures should be monitored post-intubation to prevent complications such as mucosal damage or pressure-related injuries.
63
What are the general sizing guidelines for Endotracheal Tubes (ETT) used in adults?
For adults, sizing guidelines typically range from 7.0 to 8.0 mm for orotracheal intubation, with adjustments for gender. Nasotracheal intubation may require a reduction in size.
64
How do sizing guidelines differ between orotracheal and nasotracheal intubation?
Orotracheal intubation generally requires larger tube sizes compared to nasotracheal intubation due to anatomical differences and comfort considerations.
65
how to estimate the size of ETT in children
(age in years/4) + 4 or
(age/4) + 3.5 if using a cuffed tube
66
rough guide to depth of ETT
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
67
What is the purpose of intubating (Magill) forceps?
Intubating (Magill) forceps are used to guide the tip of the endotracheal tube through the glottic opening (vocal cords) during intubation procedures via the nasal
68
When might intubating forceps be used during intubation?
They may be used during nasotracheal intubation or in cases of difficult intubation.
69
What precaution should be taken when using intubating forceps?
Care should be taken to avoid damaging the cuff of the endotracheal tube when using intubating forceps.
70
What are introducers used for during intubation?
Introducers are helpful for more difficult intubations by assisting in guiding the endotracheal tube into the trachea.
71
How can an introducer aid in the intubation process?
Introducers can be passed through the vocal cords and then used to railroad the endotracheal tube over it, or preloaded into the endotracheal tube before the intubation attempt to facilitate the process.
72
the reliable method of checking correct positioning of the ETT
by observing a continuous, square waveform trace on the capnography
73
other ways to check good positioning of the ETT
- observe bilateral chest expansion (unreliable in obese patients or those with lung pathology)
- auscultate ( the axilla for good air entry and also the epigastrium for no gurgling or unequal movement)
74
What is capnography and its reliability in assessing tube placement?
Capnography is a method of monitoring the concentration of carbon dioxide (CO2) in exhaled breath, providing reliable feedback on tube placement.
75
Capnography is a method of monitoring the concentration of carbon dioxide (CO2) in exhaled breath, providing reliable feedback on tube placement.
Positioning pitfalls include a normal capnography trace if the tube is in one of the bronchi or in the oropharynx with just the tip between the vocal cords.
76
Positioning pitfalls include a normal capnography trace if the tube is in one of the bronchi or in the oropharynx with just the tip between the vocal cords.
In the absence of capnography:
-disposable CO2 detectors (discs) attached to the endotracheal tube may be used, although they are expensive.
-Oesophageal detector devices can confirm tracheal placement but may yield false results.
- Chest X-rays are standard for long-term intubations but are not useful for immediate determination of correct placement.
-Misting of the endotracheal tube is an unreliable sign of proper placement.
77
When is nasotracheal intubation commonly used?
Nasotracheal intubation is often used in theatre and pediatric intensive care units (PICU) as an alternative to orotracheal intubation.
78
What are the advantages of nasotracheal intubation in theatre and PICU?
In theatre, it allows the surgeon unrestricted access to the oral cavity and is commonly used for ENT, dentistry, and maxillofacial surgery. In PICU, it is generally better tolerated by patients, allows for oral cleaning, and requires less sedation.
79
Describe the technique of nasotracheal intubation.
The technique involves passing the endotracheal tube (ETT) through one nostril and guiding it through the vocal cords with the aid of a Magill forceps. The nostril should be prepared with vasoconstrictor drops to minimize bleeding, and the ETT should be softened in hot water prior to insertion. It's crucial not to force passage through the nose.
80
What are the key steps in the process of extubation?
Key steps include
-checking the patient's recovery from anesthesia,
-providing oxygen-enriched air to wash out residual anesthetic gases,
-suctioning secretions, ensuring the patient is fully conscious,
-carefully deflating the cuff, -removing the endotracheal tube,
-assessing airway patency with a facemask,
-monitoring oxygen saturation, and
-addressing any need for supplemental oxygen.
81
Why is it important to ensure the patient is fully awake before extubation?
Ensuring the patient is fully awake before extubation is crucial to avoid complications such as laryngospasm.
82
Saturation minimum after extubation
>92% room air
83
supplemental oxygen given during extubation
O2 (FiO2 <=0.4)
84
What are some complications that may arise during or after intubation?
Complications during intubation may include:
-trauma to nasal passages, lips, teeth, and soft tissues of the airway,
-bronchial intubation,
-intubation response (e.g., tachycardia, hypertension),
-increased resistance to breathing,
-obstruction of the endotracheal tube,
-esophageal intubation,
-dislodgement of the tube into the bronchus or pharynx , and
-failed intubation.
85
What are some signs of incorrect tube placement?
Signs of incorrect tube placement include no trace on capnography, which indicates the tube is in the wrong place, potentially in the esophagus.
86
What complications may occur after extubation?
Complications after extubation may include:
-laryngospasm,
-aspiration of gastric contents,
-hoarseness,
-sore throat,
-tracheal and laryngeal edema,
-ulceration of vocal cords and/or trachea, and
-tracheal stenosis after prolonged intubation.
87
How can laryngospasm be managed?
Laryngospasm can be managed by applying oxygen via a tight-fitting facemask with continuous positive airway pressure (CPAP), and if necessary, using a small dose of suxamethonium (25 mg) to reintubate.
88
What preventative measures can be taken to avoid aspiration of gastric contents?
Aspiration of gastric contents can be prevented by extubating the patient when awake and placing them in the left lateral (recovery) position to facilitate the return of protective reflexes.
89
What are supraglottic airways (SGAs) commonly referred to as?
Supraglottic airways (SGAs) are often collectively referred to as 'laryngeal mask airways' due to the popularity of the original LMA by Dr Archie Brain in the 1980s.
90
What factors determine the correct size of an SGA?
The correct size of an SGA is typically based on lean body mass, although some devices may use the patient's height. A rough guideline is to use size 3 or 4 for adult females and size 4 or 5 for adult males.
91
indications of SGA
-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 condult to assist intubation in a difficult airway using a flexible scope
-Resuscitation: Use during CPR to avoid interruptions in chest compressions for intubation
92
What are the advantages of using SGAs?
- 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 (<20hPa (cmH2O) are used
93
Disadvantages of using SGAs
-older models offering no protection from aspiration (though newer devices are better),
-ventilation not always being possible with the device, and
-the potential for laryngospasm, especially if the patient is in a light plane of anesthesia.
94
types of surgical airways
tracheostomy
cricothyroidotomy
95
indications for surgical airway include
1. Prolonged ventilation in ICU
2. Head and neck deformity / trauma
3. The “impossible intubation”
4. Difficult weaning from ventilation
5. Emergency rescue airway
96
types of airway support
-spontaneous ventilation
-mask ventilation
-supraglottic airways
-endotracheal intubation
-tracheotomy
97
