Airway management and ventilation Flashcards
(106 cards)
1
Q
Patients requiring resuscitation often have an obstructed airway what is this usually caused by ?
A
Loss of conciousness
2
Q
Although loss of conciousness is the most common cause of airway obstrcution in resuscitation attempts, can airway obstruction be the primary cause of cardiorespiratory arrest ?
A
Yes! - recall with complete airway obstruction and respiratory arrest, cardiac arrest will shortly follow.
3
Q
Why is prompt assessment with control of airway patency and provision of ventilation is essential in cardiac arrest ?
A
- This will help prevent secondary hypoxic damage to the brain and other vital organs.
- It may be impossible to restore an organised perfusing cardiac rhythm without adequate oxygenation
4
Q
Although airway management is of key importance in a resuscitation attempt, what is more important ?
A
Immediate or ASAP defibrillation
5
Q
What are the 2 different ways airway obstruction can be divided into ?
A
- Whether it is partial or complete obstruction
- AND/OR if it is upper or lower airway obstruction
6
Q
Anatomically speaking where can airway obstruction occur anywhere from?
A
From the level of the mouth or nose down to the level of the carina and bronchi
7
Q
Define the boundries of the upper and lower respiratory tract
A
Upper airway includes - Mount/nose to pharynx and larynx
Lower airway - Trachea, bronchi, bronchioles and lungs
8
Q
In the unconcious patient what is the most common site of airway obstruction?
A
The pharynx - most often at the soft palate and epiglottis rather than the tongue
9
Q
What is the function of the epiglottis ?
A
It is a flap of cartilage which is depressed to cover the trachea during swallowing
10
Q
List possible causes of upper airway obstruction
A
Vomit or blood
Trauma
Foreign bodies
Oedema/inflammation e.g. croup, epiglottitis
Burns
Anaphylaxis
11
Q
Describe what croup is
A
Croup is a viral upper respiratory tract infection which results in mucosal inflammation anywhere between the nose and trachea
It is also known as acute laryngotracheitis or acute laryngotracheobronchitis
12
Q
What is the most common cause of croup?
A
**Parainfluenza virus (accounts for the majority)
**
Others include adenoviruses, rhinoviruses, enteroviruses, RSV etc.
13
Q
What age range is croup most common ?
A
6 months - 3 years
14
Q
During what part of the year is croup most common?
A
Autumn
15
Q
What are the classic features of croup?
A
Cough - barking, seal-like which is worse at night
Stridor
Fever
Coryzal symptoms
Increased work of breathing e.g. retraction
16
Q
What should you not do in a patient with suspected croup and why?
A
The throat should be not examined due to the risk of precipitating airway obstruction.
'’Examining the throat of a child with croup can potentially precipitate laryngospasm, which is an involuntary muscular contraction of the laryngeal cords. This can lead to severe respiratory distress, known as ‘croup crisis’. The larynx in children with croup is already inflamed and narrowed (subglottic stenosis), making it highly sensitive to further irritation or trauma.’’
17
Q
How can the severity of croup be graded ?
A
Mild, moderate & severe
18
Q
What patients with croup should be admitted to hospital?
A
- Moderate or severe croup
- < 3 months of age
- Known upper airway abnormalities (e.g. Laryngomalacia, Down’s syndrome)
- Uncertainty about diagnosis (important differentials include acute epiglottitis, bacterial tracheitis, peritonsillar abscess and foreign body inhalation)
19
Q
What investigations are carried out for suspected croup?
A
Vast majority diagnosed clinically.
CXR may help - a PA view will show subglottic narrowing, commonly called the ‘steeple sign’
20
Q
What is the management of croup?
A
- A single dose of dexametasone (0.15mg/kg). If not available can use Prednisolone.
- If emergency then will need high flow O2 + NEB adrenaline.
21
Q
Define what epiglottitis is
A
- Acute epiglottitis is rare but serious infection where bacteria invade the epiglottis and cause inflammation.
- Inflammation starts on the lingual surface of the epiglottis, before rapidly spreading to other laryngeal structures including the aryepiglottic folds, the arytenoids and supraglottic larynx. The vocal cords have a tightly bound epithelium which restricts progression of the swelling, increasing pressure in a small area and consequently causing airway obstruction
22
Q
What are the most common causes of epiglottitis ?
A
- ** Haemophilus influenzae type B** - most common pre HiB vaccine.
- Now most common streptococcus species e.g. strep pnuemoniae
23
Q
What are the features of epiglottitis
A
Remember the 4 D’s
* Dyspnoea
* Dysphagia
* Drooling
* Dysphonia ‘muffled/hot potato
Symptom duration is usually** less than 12 hours** and there is typically no cough. Children will appear toxic with a high-grade fever, sore throat, dehydration and may already have signs of partial airway obstruction. Stridor is a late sign. Some children may adopt a Tripod Position
24
Q
How is epiglottitis diagnosed ?
A
Diagnosis is made by direct visualisation (only by senior/airway trained staff, see below).
However, x-rays may be done, particularly if there is concern about a foreign body:
- a lateral view in acute epiglottis will show swelling of the epiglottis - the ‘thumb sign’
- in contrast, a posterior-anterior view in croup will show subglottic narrowing, commonly called the ‘steeple sign’
25
What is the management of epiglottitis ?
* Senior involvement - ENT/anaesthetics (those able to intubate). Intubation may ne neccessary
* Oxygen
* IV abx - IV cefotaxime or ceftriaxone
* IV dex 6-8mg.
* Consider NEB adrenaline
Again do not examine the airway risk of compelte obstruction, the same as in croup
26
Obstrcution of the airway below the level of the larynx is uncommon but can occur. What are possible causes of lower airway obstruction?
* Excessive bronchial secretions
* Mucosal oedema
* Bronchospasm
* Pulmonary oedema
* Aspiration of gastric contents
* Extrinsic compression - trauma, tumours, haematoma.
27
What is the approach which should be taken to help recognise airway obstruction in unwell patients?
**LOOK, LISTEN & FEEL:
*** Look for chest and abdominal movements
* Listen and feel for airflow at the mouth and nose
28
What sounds might you hear suggesting partial airway obstruction and what does each different sound suggest for the level of airway obstruction?
* Inspiratory stridor - suggests obstruction at laryngeal level or above
* Expiratory wheeze - suggests osbtruction of lower airways
* Gurgling - suggests presence of liquid or semisolid foreign material in the upper airways
* Snoring - when the pharynx is partially occluded by the tongue or soft palate.
29
What clinical sign does complete airway obstruction cause in a patient whom is still making respiratory efforts?
See-saw breathing - this is paradoxical chest and abdominal movements
[https://www.youtube.com/watch?v=gclVGJL36W4](http://)
30
Describe the normal appearance of breathing
Chest and abdomen move in a syncronous way i.e. both move up or down.
During inspiration downward movement of the diaphragm pushes the abdomen up and outwards whilst it also lifts the chest wall/ribs
31
What are the main inspiratory muscles (used in paecful breathing)?
Diaphragm & intercostal muscles
32
What are the main accessory muscles of inspiration (used in respiratory distress)?
Sternocleidomastoid, scalene muscles, serratus anterior, pectoralis major & minor, trapezius, latissimus dorsi, erector spinae, iliocostalis lumborum, quadratus lumborum
33
Why is it important to exammine someones neck, abdomen and chest who is in respiratory distress ?
To look for abnormal breathing patterns and use of accessory muscles, tracheal tugging and intercostal/subcostal recession
34
What should you hear for each of the following on ascultation:
* Normal breathing
* Partial airway obstruction
* Complete airway obstruction
* Normal breathing - quiet vesicular breaths sounds
* Partial airway obstruction - noisy breath sounds
* Complete airway obstruction - silent chest
35
What will complete airway obstruction lead to within minutes if not already occured?
Brain and other organ hypoxic injury AND cardiac arrest
36
If someone has airway obstruction what should you give them re. O2 flow ?
High flow 15L 100% oxygen.
Once relieved the obstruction you can then worry about altering target sats to scale 1 or 2.
37
A patient with a tracheostomy tube or permanent tracehal stoma (usually after laryngectomy), may develop airway obstruction. If they do what should you do ?
Remove any obvious foreign material from the stoma/tube.
Remove the treacheostomy liner (inner tube).
If still unable to ventilate the lungs, try to pass a suction catheter to perform tracheal suctioning + attempt to ventilate.
If suction catheter will not pass then attempt to remove the tracheostomy tube and exchange it.
[https://tracheostomy.org.uk/healthcare-staff/emergency-care/emergency-algorithm-tracheostomy](http://)
38
Chocking may either cause mild or severe airway obstruction what is this based on ?
If they have an effective cough or not
Other signs are shown in the table
39
What is the management of a choking patient ?
40
How should back blows be performed ?
Stand to the side and slightly behind the patient
Support patients chest wall with one hand and lean the patient forwards
Give 5 sharp back blows between the scalpulae with the heel of your hand.
After each back blow check to see if it has relieved the airway obstruction
41
If 5 back blows fail what should be done and describe how this is performed
5 abdominal thrusts:
* Stand behind the patient, putting both arms round the upper part of their abdomen
* Place a clenched fist just under the xiphisternum
* Grasp this hand with your other hand and pull sharply inwards and upwards
* Repeat 5 times.
42
If obstruction causing choking is still not relieved after 5 back blows and then 5 abdo thrusts what should you do ?
Alternate 5 back blows with 5 abdominal thrusts until the obstruction is relieved
43
If a patient who is choking becomes unconcious what should you do ?
Start CPR - compressions may help to dislodge any foreign body
44
If CPR is commenced and the patients airway is still obstructed what is the next step ?
Once a person skilled in doing so is available undertake laryngoscopy and remove any foreign body with magill's forceps
45
What are the 3 basic manoeuvres that can be used to help relieve upper airway obstruction ?
1. Head tilt
2. Chin lift
3. Jaw thrust
46
Describe how to peform a head tilt and chin lift
* One hand on patients forehead and tilt the head back
* Then place the fingertips of the other hand underneath the patients chin and lift to stretch the anterior neck structures
[https://www.youtube.com/watch?v=xGIaINEvXiA](http://)
47
Describe how to peform a jaw thrust
* Identify the angle of the mandible
* With the index and other fingers placed behind the angle of the mandible, apply steady upwards and forwards pressure to lift the mandible
* Using the thumbs slightly open the mouth by downward displacement of the chin
[https://www.youtube.com/watch?v=NYHWfkm_0wM](http://)
48
When are jaw thrusts most effective
When applied with a head tilt & chin lift
49
The 3 basic techniques are effective for most cases where airway obstruction is caused by loss of muscle tone in the pharynx. What should you do to check if they have been effective after each manoeuvre ?
Look, listen and feel again
50
Alongside basic airway manoeuvres what can be used to help maintain somoenes airway ?
Airway adjuncts
51
What are the main airway adjuncts used in resuscitation?
* Nasopahryngeal airways
* Oropharyngeal airways; guedel
* Supraglottic airways; i-gel
52
Where does a oropharyngeal airway sit ?
Between the tongue and hard palate
53
What are the different sizes of oropharyngeal airways ?
2,3 & 4.
Used for small, medium and large adults respectively
54
Is it better to use too big or too small an oropharyngeal airway ?
Too big.
55
Should you attempt to insert an oropharyngeal airway in a concious patient ?
No! - only insert in unconcious patients as it may cause vomiting or laryngospasm if the glossopharyngeal or laryngeal reflexes are stimulated
56
Occasionally can inserting an oropharyngeal airway make airway obstruction worse?
Yes - it can occasionally push the tongue backwards or it can lodge in the vallecula or the epiglottis can obstruct its lumen
57
Describe how to insert an oropharyngeal airway
* Open patients mouth ensuring no foreign material may be pushed into the larynx (if there is suction to remove)
* Insert Guedel in the 'upside down' position
* Once at the position of the junction between hard and soft palate, rotate 180 degrees
* Advance the airway further until it lies within the pharynx
* Flattened/reinforced section of guedel should sit between patiens teeth
[https://www.youtube.com/watch?v=U96105-ZUaY](http://)
58
What does the 'upside down' technique reduce the risk of when inserting a guedel ?
Reduces the risk of pushing the tongue back and making the airway obstruction worse
59
If a patient gags or stains when inserting a guedel what should you do ?
Remove the guedel - risk of causing vomiting or laryngospasm
60
How do you use suction if somoene has a guedel inserted?
Through the guedel
61
If someone has a naso or oropharyngeal airway do you still use basic airway manoeuvres to help maintain patency ?
Yes
62
In patients whom are not deeply unconcious which is better tolerated a naso or oropharyngeal airway?
Nasopharyngeal
63
What specific situations are nasopharyngeal airways particularly useful?
* Those with clentched jaws
* Trismus
* Maxillofacial injuries
64
What is the main contraindication to nasopharyngeal airway insertion?
* If someone has a known or suspected basal skul fracture
* Note tho if cannot insert oropharyngeal aiway then would still attempt nasopharyngeal insertion.
65
Are sizing methods of nasopharyngeal airways reliable ?
No
Can use - tip of the patient’s nose to the tragus of the ear
66
What size of nasopharyngeal airways is appropriate for most adults?
6-7mm
67
What are the potential complications of nasopharyngeal airway insertion?
* In 30% they cause bleeding
* Can also cause vomiting or laryngospasm due to glossopharyngeal or laryngeal reflex stimulation.
68
Describe how to insert a nasopharyngewal airway
* Lubricate NPA
* Insert the airway bevel-end (tip away from turbinates) first and gently push and twist the airway downwards along the floor of the nasopharynx
* Right nostril preferred.
[https://www.youtube.com/watch?v=_hri0MCSFYM](http://)
69
What is the recommended O2 concentration during CPR?
Highest possible O2 concentration until ROSC
70
What are the target SpO2's following ROSC?
* Scale 1; 94-98%
* Scae 2; 88-92%
71
What is the preferred sucker for suction ?
Wide-bore (Yankauer)
72
If someone has an OPA or NPA airway in what sucker can be used down them?
Fine-bore flexible suction catheters.
73
What is the normal oxygen % of air?
21%
74
Is mouth-to-mouth resuscitation effective ?
Yes - but expired air of the rescuer is only 16-17% O2. Therefore artifical ventilation with oxygen enriched air is much more effective.
75
What is a contraindication to mouth-to-mouth resuscitation?
Confirmed or suspected covid-19 infection.
Note there are documented cases of TB infection or SARS following CPR & mouth-mouth
76
Is mouth-to-mouth or pocket mask ventilation recommended now in clinical settings?
No - due to infection risk and can have artificial ventilation
77
What can a self-inflating bag be attached too ?
A face mask, SGA or tracheal tube
78
What are the different oxygen concentrations which can be achieved with a self-inflating bag when adapted?
When used without supplemental oxygen
If high flow is attached directly to bag adjacent to air-intake - 45%
If resvoir system attached (as per photo) - 85%
79
If not skilled enough what is the risk of attempting single person bag-valve-mask technique ?
* Gas leaks and hypoventilation of the patient due to poor seal.
* Additionally may also result in gas redirected into the stomach which can cause regurgitation and aspiration.
80
What is the perferred technique for bag-valve-mask ?
Two person:
* One person holding the face mask in place using a jaw thrust
* Assistant squeezing the bag
81
What airway adjunct should always be considered when using bag-valve-mask ventilation?
OPA
82
List the advantages of automatic ventilators (primary used in out-of-hospital arrests)?
* In unintubated patients they free the rescuer to have both hands for mask and airway alignment
* In intubated patients they free the rescuer for other tasks
* Once set they provide a constant tidal volume, resp rate and minute ventilatin. Thus potentially avoiding over ventilation.
83
What is the benefit of supraglottic airways (SGA) over bag-valve-mask ventilation?
May provide more effective ventilation and reduce the risk of gastric inflation (thus reduced risk of regurgitation and aspiration).
84
What is the benefit of SGA over tracheal intubation?
Easier to insertion and dont require interuption of chest compressions.
85
What is the preferred airway to be inserted during resuscitation attempts ? (if there is not someone skilled in tracheal intubation)
SGA
86
Describe how to insert an i-gel (SGA)
* Maintain chest compressions throughtout. If necessarily limit interuption to < 5secs
* Lubricate back, sides and front of i-gel with a thin layer
* Ensure patient is in 'sniffing the moring air' position
* Gently press the chin down to open mouth
* Insert with the outlet of i-gel towards the patients chin and pressing up towards hard palate
* If early resistance get an assistant to apply jaw thrust
* Glide i-gel downwards and backwards along the hard palate until definite resistance felt (at this point tip of airway should be located at upper oesophageal opening and the cuff located against the larynx.
* Incisiors should be resting against the bite block (horizontal line should be approx in line with the teeth)
[https://www.youtube.com/watch?v=tigRV3OmZWo](http://)
87
What are the limitations of SGA (i-gels)?
* Risk of seal leakage resulting in hypoventilation and potential some gastric inflation, when there is high airway resistance or poor lung compliance (pulmonary oedema, bronchospasm, COPD). Note they achieve a laryngeal seal pressure of 20-24 cmH2O.
* May need to switch back from uniterupted compressions if there is gas leakage (again causing hypoventilation and gastric inflation).
* Theoretical risk of aspiration of stomach contents
88
If you have not achieved an adequate seal with an i-gel what should you do ?
Remove and re-attempt insertion
89
Laryngeal mask airways (LMA) have similar pros and cons to what ?
SGA's
90
What is a LMA?
A wide bore tube with an elliptical inflated cuff designed to seal around the laryngeal opening.
91
What have LMA's largely been replaced by in emergency scenarios ?
SGA's due to favourable characterisitcs in emergency care scenarios
92
In practice airway management in resus scenarios takes what approach ?
A stepwise approach starting with basic techniques and moving onto advanced techniques depending on available skills.
93
What is thought to be the benefits of tracheal intubation vs bag-valve-mask technique ?
* Maintanence of a patent airway which is protected from aspiration of gastric content or blood from the oropharynx
* The ability to provide adequate tidal volume reliably even when chest compressions are uninterupted.
* Frees the rescuers hands for other tasks
* Ability to suck out airway secretions
94
What is the level of expertise someone should attain before being able to intubate during a resusictation attempt?
95% success rate within 2 attempts
95
Have randomised trials of out-of-hospital cardiac arrest looking into different airway techniques shown any one technique to be more effective ?
No
96
What are the disadvantages of tracheal intubation when compared to badg-valve-mask technique?
* Unrecognised misplaced tracheal tube - can be as high as 17%
* Prolonged interuption of chest compressions for insertion
97
Unless other airway management techniques are unsuccessful it is reasonable to defer tracheal intubation until after ROSC, in order to minimise interuptions to chest compressions.
Appreciate that point.
98
If tracheal intubation is attempted during a cardiac arrest what is used to carry it out and how quickly should it be done?
* Laryngoscopy is used to carry it out.
* Chest compressions should only be interupted when passing the tube through the vocal cords, this interuption should be < 5secs.
99
What size of laryngoscope is used for tracheal intubation and how far down should the tracheal tube go ?
After successful tracheal intubation what do you need to do with the tube ?
* Size 4MAC blade used. Tube inserted 22-23cm in males, 21-22cm in females.
* Connect it to a ventilating device and then secure it & inflate the cuff
100
After securing the trahceal tube and connecting to a ventilating device what should you imemdiately do
Confirm correct placement using primary & secondary assessment:
* Primary assessment (clinical) - observe for bilateral chest expansion & asculate ober the lungs in both axillae (should hear equal breath sounds) and over the epigastrium (no breath sounds should be heard)
* Secondary assessment - waveform capnography. Note this wont differentiate between a tube placed in a bronchus vs the trachea
101
What are the complications of tracheal intubation and which is the most serious?
* **Most serious = Misplaced - oesophageal intubation**
* Hypoxaemia whilst attempting to intubate
* Endobronchial intubation
102
What on waveform capnography confirms tracheal intubation of either the trachea or a bronchus ?
Persistence of exhaled CO2 after 6 ventilations.
103
If you get no trace on waveform capnography what does this suggest?
**No trace = wrong place**
Even during cardiac arrest you should get a small end tidal CO2. Therefore if there is no trace i.e. no end tidal CO2 it suggests tube is in the wrong place i.e. oesophagus
104
Are videolaryngoscopes beneficial?
Yes - they have been shown to improve intubation success rates when compared to direct laryngoscopy, but requries training.
105
What is the last ditch option if it is impossible to ventilate an apnoeic patient with bag-mask, SGA or tracheal intubation?
Surgical cricothyroidotomy (only by those trained).
106
Following surgical cricothyroidotomy if you manage to resuscitate the patient what will eventually be done ?
A semi-elective intubation or surgical tracheostomy.
