Chapter2: EMERGENCY MEDICINE AIRWAY
INSTRUCTIONAL OBJECTIVES
By the end of this module you should be able to :
demonstrate competence in the diagnosis and management of airway
emergencies including :
airway opening techniques
inhaled foreign bodies
epiglottitis
croup
burns
be familiar with the special considerations for facial and airway trauma
perform the following basic procedures:
head tilt
chin lift
jaw thrust
oropharyngeal airway
nasopharyngeal airway
airway suction
use of nebulised adrenaline
perform the following post basic skills :
endotracheal intubation, both basic and difficult intubation
needle cricothyroidotomy and jet insuflation
formal cricothyroidotomy
2.1 INTRODUCTION TO AIRWAY ASSESSMENT AND
MANAGEMENT
Airway is of paramount importance in any clinical setting. It must always be assessed
first, and if any compromise or potential compromise is found, this must be dealt with as
a first priority.
AN AIRWAY MUST BE :
1. Patent
Having a patent airway is an absolute first priority for any patient. An
obstructed airway can be actual (i.e. partially or completely obstructed) or
potential (eg airway burns which may result in progressive obstruction over the
following few hours).
2. Protected
This is a relative priority. It does not take priority over the initial assessment
and management of a patient's breathing and circulation.
34 Lecture Notes on Emergency Medicine
© UNIVERSITY OF STELLENBOSCH
An airway is unprotected when the normal protective reflexes are absent. This is
most commonly associated with a decreased consciousness level. A GCS of 8 or
less is usually associated with an unprotected airway.
Cervical spine protection is part of airway assessment and management. Any patient
with a decreased level of consciousness, who has had trauma to the head or neck, or
complains of neck pain, should be treated as having a potential cervical spine injury
until proved otherwise. In line immobilization of the cervical spine or protection by
a hard cervical collar must be provided while manipulating the airway.
2.2 ASSESSMENT OF AIRWAY
Assessment usually involves examination before history as the majority of cases of
airway compromise, either actual or potential, are evident by simple observation.
1. EXAMINATION - LOOKING FOR :
Signs of complete obstruction
no air movement present
grabbing at throat
paradoxical breathing with extreme respiratory distress ie abdomen moves
inwards while chest expands during attempted inspiration
cyanosis
agitation
Signs of partial obstruction
still some air movement present
stridor, cough , self posturing if patient is conscious (eg sitting up and
leaning forwards)
use of accessory muscles of respiration
cyanosis while breathing room air is a late sign of partial upper airway
obstruction
Signs of potential obstruction
normal air movement
none of the above features
swollen face, swollen tongue, sore throat, external neck trauma,
circumferential neck burns, sooty sputum, burnt mouth/tongue/nasal hairs,
history of fire or explosion in an enclosed space
Signs suggestive of difficult intubation
Signs of a non protected airway
GCS 8 or less
Absent gag/cough reflex
2. HISTORY - ASK ABOUT
symptoms of partial airway obstruction
voice changes, cough, sore throat
Features which suggest potential airway obstruction
burns in an enclosed space
history of difficult intubation
By the end of this module you should be able to :
demonstrate competence in the diagnosis and management of airway
emergencies including :
airway opening techniques
inhaled foreign bodies
epiglottitis
croup
burns
be familiar with the special considerations for facial and airway trauma
perform the following basic procedures:
head tilt
chin lift
jaw thrust
oropharyngeal airway
nasopharyngeal airway
airway suction
use of nebulised adrenaline
perform the following post basic skills :
endotracheal intubation, both basic and difficult intubation
needle cricothyroidotomy and jet insuflation
formal cricothyroidotomy
2.1 INTRODUCTION TO AIRWAY ASSESSMENT AND
MANAGEMENT
Airway is of paramount importance in any clinical setting. It must always be assessed
first, and if any compromise or potential compromise is found, this must be dealt with as
a first priority.
AN AIRWAY MUST BE :
1. Patent
Having a patent airway is an absolute first priority for any patient. An
obstructed airway can be actual (i.e. partially or completely obstructed) or
potential (eg airway burns which may result in progressive obstruction over the
following few hours).
2. Protected
This is a relative priority. It does not take priority over the initial assessment
and management of a patient's breathing and circulation.
34 Lecture Notes on Emergency Medicine
© UNIVERSITY OF STELLENBOSCH
An airway is unprotected when the normal protective reflexes are absent. This is
most commonly associated with a decreased consciousness level. A GCS of 8 or
less is usually associated with an unprotected airway.
Cervical spine protection is part of airway assessment and management. Any patient
with a decreased level of consciousness, who has had trauma to the head or neck, or
complains of neck pain, should be treated as having a potential cervical spine injury
until proved otherwise. In line immobilization of the cervical spine or protection by
a hard cervical collar must be provided while manipulating the airway.
2.2 ASSESSMENT OF AIRWAY
Assessment usually involves examination before history as the majority of cases of
airway compromise, either actual or potential, are evident by simple observation.
1. EXAMINATION - LOOKING FOR :
Signs of complete obstruction
no air movement present
grabbing at throat
paradoxical breathing with extreme respiratory distress ie abdomen moves
inwards while chest expands during attempted inspiration
cyanosis
agitation
Signs of partial obstruction
still some air movement present
stridor, cough , self posturing if patient is conscious (eg sitting up and
leaning forwards)
use of accessory muscles of respiration
cyanosis while breathing room air is a late sign of partial upper airway
obstruction
Signs of potential obstruction
normal air movement
none of the above features
swollen face, swollen tongue, sore throat, external neck trauma,
circumferential neck burns, sooty sputum, burnt mouth/tongue/nasal hairs,
history of fire or explosion in an enclosed space
Signs suggestive of difficult intubation
Signs of a non protected airway
GCS 8 or less
Absent gag/cough reflex
2. HISTORY - ASK ABOUT
symptoms of partial airway obstruction
voice changes, cough, sore throat
Features which suggest potential airway obstruction
burns in an enclosed space
history of difficult intubation
1. SIMPLE MEASURES
Position the patient eg the recovery position (left side, head down) for the
unconscious patient. This will keep both the airway patent and provide a degree
of protection.
Suction the airway to clear secretions, blood or other fluids
Heimlich manoeuvre - where appropriate
2. SIMPLE AIRWAY OPENING MANOEUVRES - PERFORMED WITH THE PATIENT
SUPINE
Head tilt : This maneouvre is performed behind or beside the patient's head.
Placing the head in the sniffing position ie with the neck flexed and the head
extended. This is contraindicated in cases of potential or actual cervical spine
injury. Great care must be taken in small children to avoid hyperextension of the
head as this itself may occlude the airway.
Chin lift : This is performed from behind or beside the patient's head. Grip the
chin from behind by placing your thumb below the lower lip, slightly retracting
it, and your fingers on the underside of the chin. With this 'pistol grip' pull the
mandible forwards and upwards. This lifts the tongue away from the posterior
wall of the pharynx.
Jaw thrust : This is performed from a position behind the patient's head. Place
your hands on either side of the head with the little fingers behind the angles of
the mandible. Then lift the mandible forward, which lifts the tongue away from
the posterior wall of the pharynx. This is the method of choice in patients with
cervical spine injury.
None of these simple airway opening techniques will provide airway protection.
3. SIMPLE ARTIFICIAL AIRWAY OPENERS
Oropharyngeal airway
This is easy to insert. The correct size is that where the length from the flange to
posterior tip reaches from the incisors to the angle of the mandible. An average
adult will take a size 3. In adults it is inserted into the mouth upside down and
then rotated through 180 degrees on reaching the oropharynx. In children it is
inserted in the position of function (a tongue depressor may be used to hold the
tongue clear) as the rotation may injure the soft palate.
Advantages
cheap
easy
effective
safe
Disadvantages
does not protect the airway
if the patient is conscious there may be gagging, coughing, straining
and vomiting.
Complications
failed placement causing airway obstruction
trauma
vomiting and aspiration
Chapter 2 AIRWAYS 37
© UNIVERSITY OF STELLENBOSCH
Nasopharyngeal airway
This is a softer artificial airway than the oropharyngeal and it is passed along
the floor of the nose into the pharynx. The correct size is that with a length from
flange to tip adequate to reach from the nares to the angle of the mandible. It
must be lubricated prior to insertion.
Advantages
can be used in patient with clenched jaw
does not cause as much gagging as an oropharyngeal airway
does not have to negotiate the tongue
Disadvantages
more difficult to insert
cannot use if possible fracture to base of skull, facial fractures
does not protect the airway
haemorrhage more likely
Complications
as for oropharyngeal airway with the addition of intracranial
placement in the setting of fractured base of skull.
4. COMPLEX OR DEFINITIVE AIRWAY TECHNIQUES
Endotracheal intubation
Laryngeal mask airway
Surgical airways
These are only for use by those skilled to do so. The timing of these interventions
depends on whether the airway compromise (to patency and protection) is actual or
potential. If it is actual and more simple manoeuvres have not been effective, then
the need for the procedure is immediate and urgent. If the airway compromise is
potential, then the procedure can be delayed until:
All appropriate staff and equipment are assembled
The patient is fully assessed with regard to breathing and circulation and
treatment of these is at least commenced, if not completed eg
pneumothoraces managed or excluded.
Neurological status has been assessed.
2.4 AIRWAY SUCTION
OBJECTIVES
To become familiar with the appropriate equipment and technique for the suctioning
of the airway.
THEORY
Obstruction of the airway may occur due to pooling of secretions, blood, vomit or
other debris in the airway. Suctioning of the airway should be done with an
appropriate size sucker and in conjunction with airway opening manoeuvres.
38 Lecture Notes on Emergency Medicine
© UNIVERSITY OF STELLENBOSCH
TECHNIQUE
1. Ensure that suction tubing is attached to the suction outlet, via a suction bottle
for collection of secretions / vomitus.
2. Tubing should be large bore to facilitate passage of blood or vomitus.
3. The sucker should be a rigid, surgical sucker with a rigid tip and large bore
openings.
4. In conjunction with basic airway opening techniques the sucker should be
gently inserted into the pharynx and mouth, and secretions removed. It may be
necessary to clear the tip to remove large particulate matter.
5. The placing of an oropharyngeal airway will prevent the patient from biting
down on the sucker.
6. In patients with clenched teeth, the airway can be suctioned with the aid of a
flexible sucker passed down a nasopharyngeal airway.
2.5 ROUTINE INTUBATION
OBJECTIVES
To know the indications for endotracheal intubation
To be able prepare for and perform safe endotracheal intubation
To be able to identify the patient who is likely to be a "difficult intubation"
To be able to prepare a Difficult Intubation Tray
To have a methodical approach to the management of a "difficult intubation"
To know and be able to perform the range of available options in the
management of the "difficult intubation"
The "BURP" technique (see later)
The laryngeal mask
Airway Bougie insertion
Needle Cricothyroidotomy
Cricothyroidotomy - open technique
- Seldinger technique
To know the advantages, disadvantages, and complications of each of the above
techniques.
INDICATIONS FOR INTUBATION
To maintain airway patency
To maintain airway protection (GCS 8 or less)
Hypoxia / hypercarbia (respiratory failure)
Provision of therapy eg hyperventilation in head injury (controversial)
Investigation eg CT scan without motion artefact
Chapter 2 AIRWAYS 39
© UNIVERSITY OF STELLENBOSCH
PREPARATION FOR ENDOTRACHEAL INTUBATION
1. The Staff
Assemble the most experienced staff available
The ideal number of staff required is 3
the person intubating
the person assigned to administer the medications and deliver the
requested equipment
the person assigned to provide cricoid pressure (or thyroid "BURP"
pressure if difficult intubation is anticipated)
A fourth staff member will be needed to perform in line stabilization of
the cervical spine if there is a possibility of injury.
Allocate and demonstrate how to perform these specific tasks before
commencing the procedure so that all are clear as to their role.
2. The equipment
Have a regular protocol established whereby all equipment required for the
procedure is checked at the start of each shift as being present and
functional.
Where time permits, recheck all equipment before commencing.
Ensure :
laryngoscope is present and working. Have a size 3 and size 4
laryngoscope blade available for adults.
an appropriate sized oropharyngeal airway is available
the bag valve mask is functional and is attached to oxygen and has an
appropriate sized face mask fitted
the appropriate sized endotracheal tube is present and, if it is cuffed,
that the cuff does not leak. Tube sizes are usually :
adult male size 8-9mm
adult female size 7-7.5mm
child 4mm + age/4 (uncuffed up to age of 8 years)
a lubricated introducer is placed inside the endotracheal tube
the Yankeur suction is working
all medications are ready and available in appropriate doses
have the "crash trolley" and Difficult Intubation Tray ready
3. The Patient
Secure IV access and flush cannula to ensure patency
Where feasible ensure the patient is fasted 4-6 hours (this is not usually
possible in the emergency setting)
If the need for intubation is not immediate, treat or exclude comorbid
conditions which may be exacerbated by intubation eg pneumothorax,
hypovolaemia
Position the patient supine with the head extended and the neck flexed.
This may be facilitated by a thin pillow being placed under the head. This
40 Lecture Notes on Emergency Medicine
© UNIVERSITY OF STELLENBOSCH
position will not only maintain an open airway to aid bag valve ventilation,
but will also aid intubation.
Cervical spine precautions should be observed where there is a likelihood
of cervical spine injury. (use in line stabilization ie a person is allocated to
squat beside the intubator and hold the patient's head at the sides without
applying traction and preventing movement as much as possible during
intubation)
Preoxygenate with 100% oxygen for 5 minutes. This is usually achieved
using a bag valve mask attached to oxygen. If the patient is breathing
spontaneously manual ventilation is not necessary and may risk gastric
distension and regugitation/aspiration.
Monitor : SaO2, ECG, BP
ENDOTRACHEAL INTUBATION
(Rapid Sequence Induction)
Position the patient eg the recovery position (left side, head down) for the
unconscious patient. This will keep both the airway patent and provide a degree
of protection.
Suction the airway to clear secretions, blood or other fluids
Heimlich manoeuvre - where appropriate
2. SIMPLE AIRWAY OPENING MANOEUVRES - PERFORMED WITH THE PATIENT
SUPINE
Head tilt : This maneouvre is performed behind or beside the patient's head.
Placing the head in the sniffing position ie with the neck flexed and the head
extended. This is contraindicated in cases of potential or actual cervical spine
injury. Great care must be taken in small children to avoid hyperextension of the
head as this itself may occlude the airway.
Chin lift : This is performed from behind or beside the patient's head. Grip the
chin from behind by placing your thumb below the lower lip, slightly retracting
it, and your fingers on the underside of the chin. With this 'pistol grip' pull the
mandible forwards and upwards. This lifts the tongue away from the posterior
wall of the pharynx.
Jaw thrust : This is performed from a position behind the patient's head. Place
your hands on either side of the head with the little fingers behind the angles of
the mandible. Then lift the mandible forward, which lifts the tongue away from
the posterior wall of the pharynx. This is the method of choice in patients with
cervical spine injury.
None of these simple airway opening techniques will provide airway protection.
3. SIMPLE ARTIFICIAL AIRWAY OPENERS
Oropharyngeal airway
This is easy to insert. The correct size is that where the length from the flange to
posterior tip reaches from the incisors to the angle of the mandible. An average
adult will take a size 3. In adults it is inserted into the mouth upside down and
then rotated through 180 degrees on reaching the oropharynx. In children it is
inserted in the position of function (a tongue depressor may be used to hold the
tongue clear) as the rotation may injure the soft palate.
Advantages
cheap
easy
effective
safe
Disadvantages
does not protect the airway
if the patient is conscious there may be gagging, coughing, straining
and vomiting.
Complications
failed placement causing airway obstruction
trauma
vomiting and aspiration
Chapter 2 AIRWAYS 37
© UNIVERSITY OF STELLENBOSCH
Nasopharyngeal airway
This is a softer artificial airway than the oropharyngeal and it is passed along
the floor of the nose into the pharynx. The correct size is that with a length from
flange to tip adequate to reach from the nares to the angle of the mandible. It
must be lubricated prior to insertion.
Advantages
can be used in patient with clenched jaw
does not cause as much gagging as an oropharyngeal airway
does not have to negotiate the tongue
Disadvantages
more difficult to insert
cannot use if possible fracture to base of skull, facial fractures
does not protect the airway
haemorrhage more likely
Complications
as for oropharyngeal airway with the addition of intracranial
placement in the setting of fractured base of skull.
4. COMPLEX OR DEFINITIVE AIRWAY TECHNIQUES
Endotracheal intubation
Laryngeal mask airway
Surgical airways
These are only for use by those skilled to do so. The timing of these interventions
depends on whether the airway compromise (to patency and protection) is actual or
potential. If it is actual and more simple manoeuvres have not been effective, then
the need for the procedure is immediate and urgent. If the airway compromise is
potential, then the procedure can be delayed until:
All appropriate staff and equipment are assembled
The patient is fully assessed with regard to breathing and circulation and
treatment of these is at least commenced, if not completed eg
pneumothoraces managed or excluded.
Neurological status has been assessed.
2.4 AIRWAY SUCTION
OBJECTIVES
To become familiar with the appropriate equipment and technique for the suctioning
of the airway.
THEORY
Obstruction of the airway may occur due to pooling of secretions, blood, vomit or
other debris in the airway. Suctioning of the airway should be done with an
appropriate size sucker and in conjunction with airway opening manoeuvres.
38 Lecture Notes on Emergency Medicine
© UNIVERSITY OF STELLENBOSCH
TECHNIQUE
1. Ensure that suction tubing is attached to the suction outlet, via a suction bottle
for collection of secretions / vomitus.
2. Tubing should be large bore to facilitate passage of blood or vomitus.
3. The sucker should be a rigid, surgical sucker with a rigid tip and large bore
openings.
4. In conjunction with basic airway opening techniques the sucker should be
gently inserted into the pharynx and mouth, and secretions removed. It may be
necessary to clear the tip to remove large particulate matter.
5. The placing of an oropharyngeal airway will prevent the patient from biting
down on the sucker.
6. In patients with clenched teeth, the airway can be suctioned with the aid of a
flexible sucker passed down a nasopharyngeal airway.
2.5 ROUTINE INTUBATION
OBJECTIVES
To know the indications for endotracheal intubation
To be able prepare for and perform safe endotracheal intubation
To be able to identify the patient who is likely to be a "difficult intubation"
To be able to prepare a Difficult Intubation Tray
To have a methodical approach to the management of a "difficult intubation"
To know and be able to perform the range of available options in the
management of the "difficult intubation"
The "BURP" technique (see later)
The laryngeal mask
Airway Bougie insertion
Needle Cricothyroidotomy
Cricothyroidotomy - open technique
- Seldinger technique
To know the advantages, disadvantages, and complications of each of the above
techniques.
INDICATIONS FOR INTUBATION
To maintain airway patency
To maintain airway protection (GCS 8 or less)
Hypoxia / hypercarbia (respiratory failure)
Provision of therapy eg hyperventilation in head injury (controversial)
Investigation eg CT scan without motion artefact
Chapter 2 AIRWAYS 39
© UNIVERSITY OF STELLENBOSCH
PREPARATION FOR ENDOTRACHEAL INTUBATION
1. The Staff
Assemble the most experienced staff available
The ideal number of staff required is 3
the person intubating
the person assigned to administer the medications and deliver the
requested equipment
the person assigned to provide cricoid pressure (or thyroid "BURP"
pressure if difficult intubation is anticipated)
A fourth staff member will be needed to perform in line stabilization of
the cervical spine if there is a possibility of injury.
Allocate and demonstrate how to perform these specific tasks before
commencing the procedure so that all are clear as to their role.
2. The equipment
Have a regular protocol established whereby all equipment required for the
procedure is checked at the start of each shift as being present and
functional.
Where time permits, recheck all equipment before commencing.
Ensure :
laryngoscope is present and working. Have a size 3 and size 4
laryngoscope blade available for adults.
an appropriate sized oropharyngeal airway is available
the bag valve mask is functional and is attached to oxygen and has an
appropriate sized face mask fitted
the appropriate sized endotracheal tube is present and, if it is cuffed,
that the cuff does not leak. Tube sizes are usually :
adult male size 8-9mm
adult female size 7-7.5mm
child 4mm + age/4 (uncuffed up to age of 8 years)
a lubricated introducer is placed inside the endotracheal tube
the Yankeur suction is working
all medications are ready and available in appropriate doses
have the "crash trolley" and Difficult Intubation Tray ready
3. The Patient
Secure IV access and flush cannula to ensure patency
Where feasible ensure the patient is fasted 4-6 hours (this is not usually
possible in the emergency setting)
If the need for intubation is not immediate, treat or exclude comorbid
conditions which may be exacerbated by intubation eg pneumothorax,
hypovolaemia
Position the patient supine with the head extended and the neck flexed.
This may be facilitated by a thin pillow being placed under the head. This
40 Lecture Notes on Emergency Medicine
© UNIVERSITY OF STELLENBOSCH
position will not only maintain an open airway to aid bag valve ventilation,
but will also aid intubation.
Cervical spine precautions should be observed where there is a likelihood
of cervical spine injury. (use in line stabilization ie a person is allocated to
squat beside the intubator and hold the patient's head at the sides without
applying traction and preventing movement as much as possible during
intubation)
Preoxygenate with 100% oxygen for 5 minutes. This is usually achieved
using a bag valve mask attached to oxygen. If the patient is breathing
spontaneously manual ventilation is not necessary and may risk gastric
distension and regugitation/aspiration.
Monitor : SaO2, ECG, BP
ENDOTRACHEAL INTUBATION
(Rapid Sequence Induction)
Preparation as above
Administer the sedation of choice eg
thiopentone 1mg/kg and titrate up to 4mg/kg as necessary
OR
midazolam 0.1-0.3mg/kg
Apply cricoid pressure
Administer neuromuscular blocker (only after patient sedated) eg
suxamethonium 1-1.5mg/kg
Holding the laryngoscope in the left hand insert the blade into the patient's
mouth, down the right side of the tongue and pushing the tongue to the left.
Insert down as far as the vallecula. Then pull forward (don't lever on the top
teeth)
Identify the vocal cords and under direct vision , pass the endotracheal tube
between the cords and on into the trachea for 3-4 cm. The tube should measure
21cm at the lips in females and 23cm in males. Remove the introducer.
Inflate the cuff until there is no air leak around it when ventilating.
Chapter 2 AIRWAYS 41
© UNIVERSITY OF STELLENBOSCH
Attach the tube to a bag valve mask attached to oxygen, manually ventilate and
confirm tube placement in trachea by assessing :
air entry in axillae
SaO2
ETCO2 (if available), this should read about 40mmHg
patient colour
ECG
BP
If any problems, extubate, reventilate, and reoxygenate with bag valve mask
attached to oxygen and re-intubate.
Release the cricoid pressure only when the tube placement is confirmed.
Anchor the endotracheal tube firmly with linen tape
Insert a nasogastric tube
Arrange a chest Xray to check for endotracheal and nasogastric tube position
and for any complications of the procedure eg pneumothorax.
COMPLICATIONS OF INTUBATION
1. During the procedure
Failed intubation with loss of airway and hypoxia
Regurgitation / vomiting and aspiration
Oesophageal intubation causing gastric distension or oesophageal trauma
Right main bronchus intubation with atelectasis of left lung and hypoxia
Trauma
airway trauma eg dental injury, haemorrhage, vocal cord injury
pneumothorax
pneumomediastinum
cervical injury or exacerbation thereof
dislocation of mandible
Complications of the drugs administered :
Thiopentone - hypotension
- histamine release
Suxamethonium - raised intracranial, intragastric and
intraocular pressure
- histamine release
- hyperkalaemia in patients with burns,
spinal injuries
- bradycardia in infants
2. While tube is in place
Tube obstruction/kinking
Tube displacement either into oesophagus or into right main bronchus
Barotrauma with pneumothorax
Aspiration
42 Lecture Notes on Emergency Medicine
© UNIVERSITY OF STELLENBOSCH
IMPORTANT POINTS
1. Always maintain a well prepared crash trolley.
2. Ensure that before intubation the staff, the equipment and the patient are
prepared as much as time allows.
3. Check all equipment before commencing.
4. If hypoxia occurs, assume tube malfunction or malposition first. If in doubt,
extubate, ventilate, re-oxygenate and re-intubate with a fresh tube.
2.6 THE DIFFICULT INTUBATION
DEFINITION
Attempted endotracheal intubation under direct vision with standard equipment that
is not achieved after two attempts.
CAUSES
Inadequate preparation / technique - most common cause of a difficult
endotracheal intubation
Anatomical
Neck : short "bull" neck
congenital abnormalities
Mandible : small, large
Teeth : abnormal dentition, especially "buck teeth"
Larynx : anterior caudal larynx
Other : excessive facial hair
pregnancy (advanced)
Pathological
Trauma - to the face or neck (blunt, penetrating, burns)
Connective tissue disease affecting the mobility of the neck or mandible
Goitre or other mass in the neck
Obesity
Airway obstruction (foreign body, epiglottitis)
ASSESSMENT
History of previous problems with airway procedures, connective tissue disease etc
Physical assessment
ability to visualize the soft palate, and in particular the uvula
ability to extend the head
recessed chin
significant upper airway bleeding
airway burns or anatomical disruption due to trauma, mass etc.
PREPARATION AND PREVENTION
Preparation has three components :
1. The Equipment
Chapter 2 AIRWAYS 43
© UNIVERSITY OF STELLENBOSCH
2. The Patient
3. The Staff
MANAGEMENT
Where difficult intubation is predicted
Call a doctor experienced in airway management before commencement (if
time allows)
Before commencing, assess whether the patient's airway and breathing can
be maintained using the bag valve mask.
Plan to attempt laryngoscopy under sedation only ie avoid using
neuromuscular blockers if possible.
Have the difficult airway tray handy
Where difficult intubation occurs
1. Stop-Reoxygenate-Rethink
Remove ETT
Attempt to re-ventilate /re-oxygenate with bag valve mask attached to
oxygen in combination with simple airway opening manoeuvres eg
jaw thrust, nasopharyngeal tube
Ask - why did the intubation fail? eg incorrect head position, incorrect
sized laryngoscope blade, inadequate preparation?
- is the intubation urgent?
- can oxygenation be maintained?
- what is the risk of aspiration?
2. Then If
Can't Intubate / Can Ventilate
Options :
- Manipulate the larynx - Backward Upward Right Pressure (see
later)
- Airway bougie (see later)
Can't intubate / Can't Ventilate
Options :
- Laryngeal Mask - size 2 for children
- size 4 for adults
Allows - positive pressure ventilation
- passage of bougie as above to facilitate intubation
- passage of a 6mm uncuffed ETT through the lumen and into the
trachea (see later)
3. If this Fails - Surgical Airway
Transtracheal jet insufflation
OR
Cricothyroidotomy
44 Lecture Notes on Emergency Medicine
© UNIVERSITY OF STELLENBOSCH
IMPORTANT POINTS
1. Predetermine lines of referral for senior medical backup if possible.
2. Be prepared with well trained staff and regularly checked equipment, including
a Difficult Airway Tray.
3. Assess the patient for evidence of possible difficulties before commencing the
procedure (if time permits)
4. If you are not an experienced intubator or difficult intubation is predicted,
summon senior help early.
5. Where difficult intubation is predicted, attempt initial laryngoscopy under
sedation alone before giving neuromuscular blockers.
6. If difficult intubation is encountered, Stop, Re-Oxygenate, Re-think.
2.6.1 Techniques for Management of Diffcult Intubation
2.6.1.1 B.U.R.P.
This applies to a technique to aid visualization of the larynx when the larynx lies caudal
and anterior. It refers to the application :
Backward - to push the larynx backwards
Upward - to push the larynx as superiorly as possible
Rightward - no more than 2cm
Pressure - to the thyroid cartilage (NB. not the cricoid)
2.6.1.2 LARYNGEAL MASK
This airway is the ideal emergency airway for use by unskilled practitioners. It however
does not provide airway protection and therefore in emergency situations should only be
seen as a temporary measure. In emergency situations it can be used as an airway in its
own right or as a track for the introduction of an airway bougie or, in adults, for the
insertion of a size 6 endotracheal tube.
TECHNIQUE
Select the appropriate size laryngeal mask
Partially inflate the cuff (this will make insertion easier)
Insert the mask into the pharynx with the distal aperture directed caudally until
no resistance to further progression is felt.
Fully inflate the cuff with air (10ml)
Attempt ventilation
If insertion fails ie if the patient cannot be ventilated, deflate the cuff and
withdraw the mask. Re-attempt the procedure with the distal aperture initially
directed cranially, then, once in the pharynx, rotate through 180 degrees as for
an oropharyngeal tube.
If desired, an airway bougie or an endotracheal tube may be passed via the lumen of
the laryngeal mask into the trachea. This requires plenty of lubricant and may require
a 90 degree rotation of the endotracheal tube to manipulate it past the fenestrations in
the aperture of the laryngeal mask.
Chapter 2 AIRWAYS 45
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COMPLICATIONS
Failed insertion
Trauma to the pharynx
Regurgitation and aspiration (the recorded incidence of this is low)
ADVANTAGES
Simple
Easy to use
Rapid
Almost foolproof
Provides not only an airway, but also a method of attaining a definitive airway
DISADVANTAGES
Does not afford airway protection and can induce gagging
2.6.1.3 AIRWAY BOUGIE
This is an extension of the concept of the introducer. A long piece of elastic material
which is semi-rigid can be directed into the trachea when it is impossible to achieve direct
intubation because of an inability to see the cords or because of difficulty in directing the
endotracheal tube between the cords.
TECHNIQUE
Under direct vision using the laryngoscope the bougie is passed between the
cords as to where the cords are estimated to be.
An appropriate sized endotracheal tube is then passed over the bougie and into
the trachea using the bougie to guide the tube
If the tube appears to catch at the cords its advancement may be facilitated by
twisting the tube through 180 degrees.
The bougie is then removed, leaving the tube in place.
COMPLICATIONS
Failed intubation
Trauma to the airway
Oesophageal intubation
ADVANTAGES
Technically simple
Avoids surgical procedures
DISADVANTAGES
Can be awkward, particularly if endotracheal tube gets snagged at the cords.
2.6.1.4 NEEDLE CRICOTHYROIDOTOMY / TRANSTRACHEAL JET
INSUFFLATION
This is a technique for achieving oxygenation. It does not provide adequate ventilation.
It is the emergency surgical airway of choice in children <12 years old. It can be useful in
severe maxillofacial trauma, but can also be used in the setting of an upper airway
obstruction from any cause.
46 Lecture Notes on Emergency Medicine
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TECHNIQUE
Inform the patient/parents if possible.
Local anaesthesia using 1% lignocaine with adrenaline. This is infiltrated into
the skin overlying the cricothyroid membrane and on to the membrane itself.
Aspiration of air will confirm the needle's passage beyond the membrane and
into the trachea.
With a 5 ml syringe attached to the cannula and aspirating as you go, advance
the cannula tip through the inferior part of the cricothyroid membrane aiming
caudally.
When air is aspirated freely, advance 1-2 mm further, stop and slide the cannula
sheath of the needle while holding the needle still. Remove the needle, leaving
the cannula sheath in place.
Now connect :
the 3 way stopcock to the cannula
the oxygen tubing to the 3 way stop cock
Commence the oxygen flow at 15 l/min and use the stop cock to control
ventilation ie on to the patient on inspiration / off to the patient for expiration.
Inspiratory phase 2 seconds, or until the chest rises.
Expiratory phase 4 seconds.
If expiration is incomplete, insert another cannula next to the first to act as a
vent.
The procedure will provide adequate oxygenation for up to 45-60 minutes.
Alternative :
A 2ml syringe can be connected to the cannula after insertion. The plunger is
removed from the syringe and the connector from a size 7 ETT is inserted in its
place. A bag and valve attached to oxygen can then be connected and the patient
oxygenated.
COMPLICATIONS
Malposition
subcutaneous emphysema
haemorrhage
Injury to nearby structures
vocal cords
cricoid cartilage
trachea
carotid arteries
vagus / recurrent laryngeal nerves
jugular veins
oesophagus
Barotrauma
especially in infants or in patients with complete upper airway obsrtuction
Infection
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ADVANTAGES
Less complications than surgical airways
Easier than other surgical airways
Requires minimal surgical skills
Can be used in young children
DISADVANTAGES
Does not provide a definitive airway
Does not provide adequate ventilation
Exposes the lungs to potentially high pressures
2.6.1.5 FORMAL CRICOTHYROIDOTOMY (SELDINGER TECHNIQUE)
Several commercial sets exist. Many are based on the Seldinger guidewire principle :
Identfy the cricothyroid membrane by placing the index finger and thumb on the
thyroid cartilages and running them caudally until they fall into a groove. The floor
of this groove is the crocothyroid membrane.
Local anaesthesia, using 1% lignocaine with adrenaline, is infiltrated down to the
caudal limit of the cricothyroid membrane.
A needle with syringe attached is inserted in the midline through the caudal edge of
the membrane while aspirating. Free aspiration of air indicates penetration into the
trachea.
The syringe is disconnected from the needle and a guidewire passed caudally into the
trachea.
A dilator is then passed over the wire and used to create a passage for the tube.
The dilator is then removed leaving the wire in situ.
A trochar with tube is then inserted over the wire and once in place, the wire and
trochar are removed leaving the tube in situ.
The tube is then tied in place.
Arrange a CXR
Administer the sedation of choice eg
thiopentone 1mg/kg and titrate up to 4mg/kg as necessary
OR
midazolam 0.1-0.3mg/kg
Apply cricoid pressure
Administer neuromuscular blocker (only after patient sedated) eg
suxamethonium 1-1.5mg/kg
Holding the laryngoscope in the left hand insert the blade into the patient's
mouth, down the right side of the tongue and pushing the tongue to the left.
Insert down as far as the vallecula. Then pull forward (don't lever on the top
teeth)
Identify the vocal cords and under direct vision , pass the endotracheal tube
between the cords and on into the trachea for 3-4 cm. The tube should measure
21cm at the lips in females and 23cm in males. Remove the introducer.
Inflate the cuff until there is no air leak around it when ventilating.
Chapter 2 AIRWAYS 41
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Attach the tube to a bag valve mask attached to oxygen, manually ventilate and
confirm tube placement in trachea by assessing :
air entry in axillae
SaO2
ETCO2 (if available), this should read about 40mmHg
patient colour
ECG
BP
If any problems, extubate, reventilate, and reoxygenate with bag valve mask
attached to oxygen and re-intubate.
Release the cricoid pressure only when the tube placement is confirmed.
Anchor the endotracheal tube firmly with linen tape
Insert a nasogastric tube
Arrange a chest Xray to check for endotracheal and nasogastric tube position
and for any complications of the procedure eg pneumothorax.
COMPLICATIONS OF INTUBATION
1. During the procedure
Failed intubation with loss of airway and hypoxia
Regurgitation / vomiting and aspiration
Oesophageal intubation causing gastric distension or oesophageal trauma
Right main bronchus intubation with atelectasis of left lung and hypoxia
Trauma
airway trauma eg dental injury, haemorrhage, vocal cord injury
pneumothorax
pneumomediastinum
cervical injury or exacerbation thereof
dislocation of mandible
Complications of the drugs administered :
Thiopentone - hypotension
- histamine release
Suxamethonium - raised intracranial, intragastric and
intraocular pressure
- histamine release
- hyperkalaemia in patients with burns,
spinal injuries
- bradycardia in infants
2. While tube is in place
Tube obstruction/kinking
Tube displacement either into oesophagus or into right main bronchus
Barotrauma with pneumothorax
Aspiration
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IMPORTANT POINTS
1. Always maintain a well prepared crash trolley.
2. Ensure that before intubation the staff, the equipment and the patient are
prepared as much as time allows.
3. Check all equipment before commencing.
4. If hypoxia occurs, assume tube malfunction or malposition first. If in doubt,
extubate, ventilate, re-oxygenate and re-intubate with a fresh tube.
2.6 THE DIFFICULT INTUBATION
DEFINITION
Attempted endotracheal intubation under direct vision with standard equipment that
is not achieved after two attempts.
CAUSES
Inadequate preparation / technique - most common cause of a difficult
endotracheal intubation
Anatomical
Neck : short "bull" neck
congenital abnormalities
Mandible : small, large
Teeth : abnormal dentition, especially "buck teeth"
Larynx : anterior caudal larynx
Other : excessive facial hair
pregnancy (advanced)
Pathological
Trauma - to the face or neck (blunt, penetrating, burns)
Connective tissue disease affecting the mobility of the neck or mandible
Goitre or other mass in the neck
Obesity
Airway obstruction (foreign body, epiglottitis)
ASSESSMENT
History of previous problems with airway procedures, connective tissue disease etc
Physical assessment
ability to visualize the soft palate, and in particular the uvula
ability to extend the head
recessed chin
significant upper airway bleeding
airway burns or anatomical disruption due to trauma, mass etc.
PREPARATION AND PREVENTION
Preparation has three components :
1. The Equipment
Chapter 2 AIRWAYS 43
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2. The Patient
3. The Staff
MANAGEMENT
Where difficult intubation is predicted
Call a doctor experienced in airway management before commencement (if
time allows)
Before commencing, assess whether the patient's airway and breathing can
be maintained using the bag valve mask.
Plan to attempt laryngoscopy under sedation only ie avoid using
neuromuscular blockers if possible.
Have the difficult airway tray handy
Where difficult intubation occurs
1. Stop-Reoxygenate-Rethink
Remove ETT
Attempt to re-ventilate /re-oxygenate with bag valve mask attached to
oxygen in combination with simple airway opening manoeuvres eg
jaw thrust, nasopharyngeal tube
Ask - why did the intubation fail? eg incorrect head position, incorrect
sized laryngoscope blade, inadequate preparation?
- is the intubation urgent?
- can oxygenation be maintained?
- what is the risk of aspiration?
2. Then If
Can't Intubate / Can Ventilate
Options :
- Manipulate the larynx - Backward Upward Right Pressure (see
later)
- Airway bougie (see later)
Can't intubate / Can't Ventilate
Options :
- Laryngeal Mask - size 2 for children
- size 4 for adults
Allows - positive pressure ventilation
- passage of bougie as above to facilitate intubation
- passage of a 6mm uncuffed ETT through the lumen and into the
trachea (see later)
3. If this Fails - Surgical Airway
Transtracheal jet insufflation
OR
Cricothyroidotomy
44 Lecture Notes on Emergency Medicine
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IMPORTANT POINTS
1. Predetermine lines of referral for senior medical backup if possible.
2. Be prepared with well trained staff and regularly checked equipment, including
a Difficult Airway Tray.
3. Assess the patient for evidence of possible difficulties before commencing the
procedure (if time permits)
4. If you are not an experienced intubator or difficult intubation is predicted,
summon senior help early.
5. Where difficult intubation is predicted, attempt initial laryngoscopy under
sedation alone before giving neuromuscular blockers.
6. If difficult intubation is encountered, Stop, Re-Oxygenate, Re-think.
2.6.1 Techniques for Management of Diffcult Intubation
2.6.1.1 B.U.R.P.
This applies to a technique to aid visualization of the larynx when the larynx lies caudal
and anterior. It refers to the application :
Backward - to push the larynx backwards
Upward - to push the larynx as superiorly as possible
Rightward - no more than 2cm
Pressure - to the thyroid cartilage (NB. not the cricoid)
2.6.1.2 LARYNGEAL MASK
This airway is the ideal emergency airway for use by unskilled practitioners. It however
does not provide airway protection and therefore in emergency situations should only be
seen as a temporary measure. In emergency situations it can be used as an airway in its
own right or as a track for the introduction of an airway bougie or, in adults, for the
insertion of a size 6 endotracheal tube.
TECHNIQUE
Select the appropriate size laryngeal mask
Partially inflate the cuff (this will make insertion easier)
Insert the mask into the pharynx with the distal aperture directed caudally until
no resistance to further progression is felt.
Fully inflate the cuff with air (10ml)
Attempt ventilation
If insertion fails ie if the patient cannot be ventilated, deflate the cuff and
withdraw the mask. Re-attempt the procedure with the distal aperture initially
directed cranially, then, once in the pharynx, rotate through 180 degrees as for
an oropharyngeal tube.
If desired, an airway bougie or an endotracheal tube may be passed via the lumen of
the laryngeal mask into the trachea. This requires plenty of lubricant and may require
a 90 degree rotation of the endotracheal tube to manipulate it past the fenestrations in
the aperture of the laryngeal mask.
Chapter 2 AIRWAYS 45
© UNIVERSITY OF STELLENBOSCH
COMPLICATIONS
Failed insertion
Trauma to the pharynx
Regurgitation and aspiration (the recorded incidence of this is low)
ADVANTAGES
Simple
Easy to use
Rapid
Almost foolproof
Provides not only an airway, but also a method of attaining a definitive airway
DISADVANTAGES
Does not afford airway protection and can induce gagging
2.6.1.3 AIRWAY BOUGIE
This is an extension of the concept of the introducer. A long piece of elastic material
which is semi-rigid can be directed into the trachea when it is impossible to achieve direct
intubation because of an inability to see the cords or because of difficulty in directing the
endotracheal tube between the cords.
TECHNIQUE
Under direct vision using the laryngoscope the bougie is passed between the
cords as to where the cords are estimated to be.
An appropriate sized endotracheal tube is then passed over the bougie and into
the trachea using the bougie to guide the tube
If the tube appears to catch at the cords its advancement may be facilitated by
twisting the tube through 180 degrees.
The bougie is then removed, leaving the tube in place.
COMPLICATIONS
Failed intubation
Trauma to the airway
Oesophageal intubation
ADVANTAGES
Technically simple
Avoids surgical procedures
DISADVANTAGES
Can be awkward, particularly if endotracheal tube gets snagged at the cords.
2.6.1.4 NEEDLE CRICOTHYROIDOTOMY / TRANSTRACHEAL JET
INSUFFLATION
This is a technique for achieving oxygenation. It does not provide adequate ventilation.
It is the emergency surgical airway of choice in children <12 years old. It can be useful in
severe maxillofacial trauma, but can also be used in the setting of an upper airway
obstruction from any cause.
46 Lecture Notes on Emergency Medicine
© UNIVERSITY OF STELLENBOSCH
TECHNIQUE
Inform the patient/parents if possible.
Local anaesthesia using 1% lignocaine with adrenaline. This is infiltrated into
the skin overlying the cricothyroid membrane and on to the membrane itself.
Aspiration of air will confirm the needle's passage beyond the membrane and
into the trachea.
With a 5 ml syringe attached to the cannula and aspirating as you go, advance
the cannula tip through the inferior part of the cricothyroid membrane aiming
caudally.
When air is aspirated freely, advance 1-2 mm further, stop and slide the cannula
sheath of the needle while holding the needle still. Remove the needle, leaving
the cannula sheath in place.
Now connect :
the 3 way stopcock to the cannula
the oxygen tubing to the 3 way stop cock
Commence the oxygen flow at 15 l/min and use the stop cock to control
ventilation ie on to the patient on inspiration / off to the patient for expiration.
Inspiratory phase 2 seconds, or until the chest rises.
Expiratory phase 4 seconds.
If expiration is incomplete, insert another cannula next to the first to act as a
vent.
The procedure will provide adequate oxygenation for up to 45-60 minutes.
Alternative :
A 2ml syringe can be connected to the cannula after insertion. The plunger is
removed from the syringe and the connector from a size 7 ETT is inserted in its
place. A bag and valve attached to oxygen can then be connected and the patient
oxygenated.
COMPLICATIONS
Malposition
subcutaneous emphysema
haemorrhage
Injury to nearby structures
vocal cords
cricoid cartilage
trachea
carotid arteries
vagus / recurrent laryngeal nerves
jugular veins
oesophagus
Barotrauma
especially in infants or in patients with complete upper airway obsrtuction
Infection
Chapter 2 AIRWAYS 47
© UNIVERSITY OF STELLENBOSCH
ADVANTAGES
Less complications than surgical airways
Easier than other surgical airways
Requires minimal surgical skills
Can be used in young children
DISADVANTAGES
Does not provide a definitive airway
Does not provide adequate ventilation
Exposes the lungs to potentially high pressures
2.6.1.5 FORMAL CRICOTHYROIDOTOMY (SELDINGER TECHNIQUE)
Several commercial sets exist. Many are based on the Seldinger guidewire principle :
Identfy the cricothyroid membrane by placing the index finger and thumb on the
thyroid cartilages and running them caudally until they fall into a groove. The floor
of this groove is the crocothyroid membrane.
Local anaesthesia, using 1% lignocaine with adrenaline, is infiltrated down to the
caudal limit of the cricothyroid membrane.
A needle with syringe attached is inserted in the midline through the caudal edge of
the membrane while aspirating. Free aspiration of air indicates penetration into the
trachea.
The syringe is disconnected from the needle and a guidewire passed caudally into the
trachea.
A dilator is then passed over the wire and used to create a passage for the tube.
The dilator is then removed leaving the wire in situ.
A trochar with tube is then inserted over the wire and once in place, the wire and
trochar are removed leaving the tube in situ.
The tube is then tied in place.
Arrange a CXR
2.6.1.6 FORMAL CRICOTHYROIDOTOMY (SURGICAL)
TECHNIQUE
Identify the cricothyroid membrane as above
Infiltrate with local anaesthetic using 1% lignocaine with adrenaline
Using the scalpel make a vertical incision through the skin and down to the
membrane
Make a horizontal incision through the cricothyroid membrane at its junction
with the cricoid cartilage
Use the forceps and scissors to open the aperture and pass the tube into the
trachea
Remove the forceps, inflate the cuff and anchor the tube
Arrange a CXR
Chapter 2 AIRWAYS 49
© UNIVERSITY OF STELLENBOSCH
COMPLICATIONS
Malposition
subcutaneous emphysema
injury to nearby structures (as above)
Haemorrhage
Failure and resultant hypoxia
Infection
ADVANTAGES
Provides a definitive and stable airway
Simpler and safer than a tracheostomy
Rapid
DISADVANTAGES
Landmarks are often difficult in the clinical settings in which it is needed
Needs some surgical skill
Is not recommended in a child <12 years
Seldinger sets are expensive
2.7 ACUTE UPPER AIRWAY OBSTRUCTION
DEFINITION
A life threatening condition where there is complete, partial or potential obstruction
of the airway at some point between the teeth and the carina. The degree of
obstruction and the speed of onset will vary depending on the cause.
CAUSES
1. The Patient's Tongue - this occurs in unconscious patients who are unable to
maintain airway patency
2. Foreign Body - usually occurs in one of three clinical situations
Patients with a decreased level of consciousness and a diminished cough
reflex who inhale a foreign body
Young children inhaling objects/material that they have put into their
mouths
Older patients with dentures who lack the ability to sense the size of the
food bolus they are about to swallow
3. Upper Airways Swelling - due to infection /burns / trauma / oedema
CLINICAL FEATURES
Complete Obstruction
no air movement present
until the patient loses consciousness there will be :
grabbing at throat
paradoxical breathing with extreme respiratory distress
cyanosis
agitation
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Partial Obstruction
still some air movement present
stridor, cough, self posturing if the patient is conscious (eg sitting up,
leaning forwards)
use of accessory muscles of respiration
cyanosis while breathing room air is a late sign of partial upper airway
obstruction
Potential Obstruction
normal air movement
none of the above features
swollen face, swollen tongue, sore throat, external neck trauma,
circumferential neck burns, sooty sputum, burnt mouth / tongue / nasal
hairs, history of fire or explosion in an enclosed space.
IMPORTANT POINTS
1. Cyanosis while breathing room air is a late sign of upper airway obstruction
2. Early upper airway swelling can be very subtle and initially have no clinical
evidence of obstruction, yet dramatically obstruct later.
3. Skilled assistance is vital and the doctor most experienced in airway
management should be summoned immediately.
2.7.1 Management of Upper Airway Obstruction
INITIAL STABILIZATION
1. Airway
- have a difficult airway tray at hand
Complete Obstruction
In the emergency Department setting manual manoeuvres (eg
Heimlich manoeuvre) to relieve obstruction are not indicated as more
definitive measures exist.
Initially, use basic airway opening measures and attempt ventilation
via bag valve mask attached to oxygen
Then attempt indirect laryngoscopy and removal of obstructing agent
with a Magill's forceps or suction
If unable to remove the obstruction mechanically eg when due to
swelling, proceed to emergency surgical airway ie transtracheal jet
insufflation or cricothyroidotomy
Then proceed as per "Specific Treatment" below.
Partial Obstruction
Encourage self posturing eg in epiglottitis the patient will prefer to sit
upright and lean forwards
Unless there is an obviously visible foreign body and the patient is
cooperative DO NOT perform any airway clearing manoeuvres,
such as the Hiemlich manoeuvre. This may convert a partial
obstruction into a complete one.
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Potential Obstruction
No immediate intervention is required
Then, for partial obstruction or potential obstruction :
2. Breathing
Measure respiratory rate. If inadequate, assist ventilation with bag valve
mask attached to oxygen.
Measure SaO2. If < 95% and not requiring ventilation, administer high
flow oxygen by mask.
3. Circulation
In partial obstruction great care must be taken to avoid agitating the patient and
precipitating a complete obstruction eg measuring the BP or inserting a cannula
in a child with epiglottis may cause agitation and precipitate a complete airway
obstruction.
4. Disability
Record a GCS and pupil response. Consider intubation (if this has not
already occurred), if GCS is 8 or less to protect the airway.
5. Monitor
ECG, SaO2, BP (if this will not agitate the patient)
6. Summon
- a senior doctor with airway skills.
DIRECTED HISTORY AND EXAMINATION
Ask About :
Event
precipitating factors, likelihood of foreign body aspiration
Symptoms
of possible precipitants eg epiglottitis, croup
Past History
drug allergies
medications
medical problems
Look For :
stridor, cyanosis
signs suggestive of particular clinical syndromes eg epiglottitis, croup,
angio-oedema
Measure :
reassess SaO2, respiratory rate, level of consciousness
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Tests
in the airway control phase there is no test of any use and tests may delay
definitive management and worsen the condition.
SPECIFIC TREATMENT
If partial obstruction, potential obstruction or complete obstruction with
temporary surgical airway in place :
1. Notify anaesthetist /ENT surgeon or local equivalents
2. Notify the operating theatre
3. When all resources are assembled transfer to the operating theatres
accompanied by skilled staff, oxygen, suction, bag valve mask system, difficult
intubation tray and surgical airway setup.
DISPOSITION
Depends on the cause, but in most cases would require admission to an
Intensive Care Unit after definitive treatment in the operating theatre.
Airway must be stabilized before any inter-hospital transfer is attempted.
IMPORTANT POINTS
1. Heimlich manoeuvre is generally not indicated in the Emergency Department
setting.
2. If partial airway obstruction is present then intervention in the Emergency
Department should be minimal and the patient should be transferred to the
operating theatre accompanied by appropriate staff and equipment.
3. Do not attempt to remove penetrating foreign bodies of the neck in the
Emergency Department.
2.8 UPPER AIRWAYS BURNS
DEFINITION
Thermal or caustic burns to the pharynx, larynx or trachea.
1. Thermal Burns
Heated gases
pharyngeal, laryngeal, and tracheal burns are usually the worse
affected areas
Direct Flame
injuries usually confined to the face and lips
2. Caustic Burns
acid / alkali
intentional or accidental
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CLINICAL FEATURES
1. Thermal Burns
The initial physical findings are notoriously unreliable at ruling out burns
to the airway.
Suggestive findings are :
history of burns in an enclosed space
sore throat, painful swallowing
facial, nasal or oral burns
cough, stridor or voice changes
carbonaceous sputum or respiratory distress
2. Caustic Burns
associated with mucosal ulceration and massive oedema
drooling
cough, stridor
ulceration of the mouth, tongue or pharynx (may appear as white plaques)
respiratory distress
IMPORTANT POINTS
1. The initial physical findings can be unreliable in ruling out thermal burns to the
upper airway.
2. History of the circumstances of the burn is important to assess the possibility of
airway burns (eg confined space, explosion, flame, steam)
3. If thermal upper airway burns are present, also consider carbon monoxide,
cyanide or hydrogen sulphide poisoning from smoke inhalation.
4. If caustic burns are present, consider other ingestants as well
5. Airway compromise can be delayed but dramatic in onset.
2.8.1 Management of Upper Airways Burns
INITIAL STABILISATION
1. Airway
Complete Obstruction
summon help from the doctor most experienced in airway
management.
Use basic airway opening techniques (eg suction , head position,
oropharyngeal airway, nasopharyngeal airway) and attempt ventilation
via bag valve mask attached to oxygen
Attempt intubation without the use of muscle relaxants initially
If unsuccessful, proceed to emergency surgical airway
Partial Obstruction
Diagnosis based on the presence of stridor, hoarse voice and/or respiratory
distress.
Humidified oxygen
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Notify anaesthetist/surgeon
Transfer to operating theatre accompanied by skilled staff for
examination under anaesthetic/intubation or tracheostomy
Do not transfer the patient to another institution until intubated
Potential Obstruction
Diagnosis based on the presence of sore throat, circumferential neck burns,
sooty sputum, burnt mouth/tongue/nasal hairs or history of fire or
explosion in confined space. Consider intubation.
2. Breathing
Measure respiratory rate, and if inadequate, assist ventilation with bag
valve mask attached to oxygen.
Measure SaO2. If <95% and not requiring assisted ventilation, administer
high flow oxygen ( 100% O2 via non rebreather mask if carbon monoxide
poisoning is a possibility)
3. Circulation
Measure pulse rate, BP and capillary refill
Attach to a cardiac monitor and assess the rhythm
Insert IV cannula
Take blood for FBC, biochemistry
4. Disability
Record a GCS and pupil response. Consider intubation (if this has not already
been done), if GCS 8 or below, to protect the airway.
5. Monitor
- BP, ECG, SaO2
6. Summon
senior doctor with airway skills
DIRECTED HISTORY AND EXAMINATION
Ask about
Event
Circumstances of the burn(eg enclosed area, explosion, steam)
Associated trauma if explosion was involved
Episodes of loss of consciousness (possibly associated carbon
monoxide poisoning or head injury)
Symptoms
stridor/dyspnoea
cough
sore mouth/throat
hoarse voice
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Past History
associated respiratory illnesses (eg asthma)
medications
allergies
medical problems
Look for
Stridor, voice changes, oral or nasal burns, facial or circumferential neck burns,
nature of cough
Tests
Blood gases, Carboxy Hb
DISPOSITION
For complete obstruction with surgical airway in place or partial obstruction:
Notify anaesthetist, ENT surgeon
Notify operating theatres
When all resources are assembled transfer to the operating theatres
accompanied by skilled staff, oxygen, Ambu bag, difficult intubation tray
and surgical airway equipment
For potential obstruction, admit to an Intensive Care Unit
If patient transfer is to occur, consider intubation prior to transfer
IMPORTANT POINTS
1. Intubate early if signs or history suggesting airway involvement in burns.
2. Be prepared for a difficult intubation.
3. Involve the available doctor most experienced in airway management.
2.9 UPPER AIRWAY TRAUMA
DEFINITION
Blunt or penetrating traumas to the neck or face involving elements of the upper
airway.
CAUSES
1. Motor vehicle accidents
2. Assaults
3. Falls
4. Hanging
5. Penetrating injuries
CLINICAL FEATURES
1. Airway obstruction is the greatest concern and can be due to :
collapse of anatomical structures (eg mid face, mandible, larynx)
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foreign bodies
haemorrhage
swelling
Complete Obstruction
no air movement present
until the patient loses consciousness there will be
- grabbing at throat
- paradoxical breathing ie abdomen moves inwards while chest
expands during attempted inspiration
- extensive use of accessory muscles of respiration
- cyanosis
- agitation
Partial Obstruction
still some air movement present
stridor, cough, self posturing (eg sitting upright and leaning forward)
use of accessory muscles of respiration
cyanosis while breathing room air is a late sign of partial upper
airway obstruction
Potential Obstruction
normal air movement
none of the above features, but
swollen face, swollen tongue, sore throat, external neck trauma
Identify the cricothyroid membrane as above
Infiltrate with local anaesthetic using 1% lignocaine with adrenaline
Using the scalpel make a vertical incision through the skin and down to the
membrane
Make a horizontal incision through the cricothyroid membrane at its junction
with the cricoid cartilage
Use the forceps and scissors to open the aperture and pass the tube into the
trachea
Remove the forceps, inflate the cuff and anchor the tube
Arrange a CXR
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COMPLICATIONS
Malposition
subcutaneous emphysema
injury to nearby structures (as above)
Haemorrhage
Failure and resultant hypoxia
Infection
ADVANTAGES
Provides a definitive and stable airway
Simpler and safer than a tracheostomy
Rapid
DISADVANTAGES
Landmarks are often difficult in the clinical settings in which it is needed
Needs some surgical skill
Is not recommended in a child <12 years
Seldinger sets are expensive
2.7 ACUTE UPPER AIRWAY OBSTRUCTION
DEFINITION
A life threatening condition where there is complete, partial or potential obstruction
of the airway at some point between the teeth and the carina. The degree of
obstruction and the speed of onset will vary depending on the cause.
CAUSES
1. The Patient's Tongue - this occurs in unconscious patients who are unable to
maintain airway patency
2. Foreign Body - usually occurs in one of three clinical situations
Patients with a decreased level of consciousness and a diminished cough
reflex who inhale a foreign body
Young children inhaling objects/material that they have put into their
mouths
Older patients with dentures who lack the ability to sense the size of the
food bolus they are about to swallow
3. Upper Airways Swelling - due to infection /burns / trauma / oedema
CLINICAL FEATURES
Complete Obstruction
no air movement present
until the patient loses consciousness there will be :
grabbing at throat
paradoxical breathing with extreme respiratory distress
cyanosis
agitation
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Partial Obstruction
still some air movement present
stridor, cough, self posturing if the patient is conscious (eg sitting up,
leaning forwards)
use of accessory muscles of respiration
cyanosis while breathing room air is a late sign of partial upper airway
obstruction
Potential Obstruction
normal air movement
none of the above features
swollen face, swollen tongue, sore throat, external neck trauma,
circumferential neck burns, sooty sputum, burnt mouth / tongue / nasal
hairs, history of fire or explosion in an enclosed space.
IMPORTANT POINTS
1. Cyanosis while breathing room air is a late sign of upper airway obstruction
2. Early upper airway swelling can be very subtle and initially have no clinical
evidence of obstruction, yet dramatically obstruct later.
3. Skilled assistance is vital and the doctor most experienced in airway
management should be summoned immediately.
2.7.1 Management of Upper Airway Obstruction
INITIAL STABILIZATION
1. Airway
- have a difficult airway tray at hand
Complete Obstruction
In the emergency Department setting manual manoeuvres (eg
Heimlich manoeuvre) to relieve obstruction are not indicated as more
definitive measures exist.
Initially, use basic airway opening measures and attempt ventilation
via bag valve mask attached to oxygen
Then attempt indirect laryngoscopy and removal of obstructing agent
with a Magill's forceps or suction
If unable to remove the obstruction mechanically eg when due to
swelling, proceed to emergency surgical airway ie transtracheal jet
insufflation or cricothyroidotomy
Then proceed as per "Specific Treatment" below.
Partial Obstruction
Encourage self posturing eg in epiglottitis the patient will prefer to sit
upright and lean forwards
Unless there is an obviously visible foreign body and the patient is
cooperative DO NOT perform any airway clearing manoeuvres,
such as the Hiemlich manoeuvre. This may convert a partial
obstruction into a complete one.
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Potential Obstruction
No immediate intervention is required
Then, for partial obstruction or potential obstruction :
2. Breathing
Measure respiratory rate. If inadequate, assist ventilation with bag valve
mask attached to oxygen.
Measure SaO2. If < 95% and not requiring ventilation, administer high
flow oxygen by mask.
3. Circulation
In partial obstruction great care must be taken to avoid agitating the patient and
precipitating a complete obstruction eg measuring the BP or inserting a cannula
in a child with epiglottis may cause agitation and precipitate a complete airway
obstruction.
4. Disability
Record a GCS and pupil response. Consider intubation (if this has not
already occurred), if GCS is 8 or less to protect the airway.
5. Monitor
ECG, SaO2, BP (if this will not agitate the patient)
6. Summon
- a senior doctor with airway skills.
DIRECTED HISTORY AND EXAMINATION
Ask About :
Event
precipitating factors, likelihood of foreign body aspiration
Symptoms
of possible precipitants eg epiglottitis, croup
Past History
drug allergies
medications
medical problems
Look For :
stridor, cyanosis
signs suggestive of particular clinical syndromes eg epiglottitis, croup,
angio-oedema
Measure :
reassess SaO2, respiratory rate, level of consciousness
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Tests
in the airway control phase there is no test of any use and tests may delay
definitive management and worsen the condition.
SPECIFIC TREATMENT
If partial obstruction, potential obstruction or complete obstruction with
temporary surgical airway in place :
1. Notify anaesthetist /ENT surgeon or local equivalents
2. Notify the operating theatre
3. When all resources are assembled transfer to the operating theatres
accompanied by skilled staff, oxygen, suction, bag valve mask system, difficult
intubation tray and surgical airway setup.
DISPOSITION
Depends on the cause, but in most cases would require admission to an
Intensive Care Unit after definitive treatment in the operating theatre.
Airway must be stabilized before any inter-hospital transfer is attempted.
IMPORTANT POINTS
1. Heimlich manoeuvre is generally not indicated in the Emergency Department
setting.
2. If partial airway obstruction is present then intervention in the Emergency
Department should be minimal and the patient should be transferred to the
operating theatre accompanied by appropriate staff and equipment.
3. Do not attempt to remove penetrating foreign bodies of the neck in the
Emergency Department.
2.8 UPPER AIRWAYS BURNS
DEFINITION
Thermal or caustic burns to the pharynx, larynx or trachea.
1. Thermal Burns
Heated gases
pharyngeal, laryngeal, and tracheal burns are usually the worse
affected areas
Direct Flame
injuries usually confined to the face and lips
2. Caustic Burns
acid / alkali
intentional or accidental
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CLINICAL FEATURES
1. Thermal Burns
The initial physical findings are notoriously unreliable at ruling out burns
to the airway.
Suggestive findings are :
history of burns in an enclosed space
sore throat, painful swallowing
facial, nasal or oral burns
cough, stridor or voice changes
carbonaceous sputum or respiratory distress
2. Caustic Burns
associated with mucosal ulceration and massive oedema
drooling
cough, stridor
ulceration of the mouth, tongue or pharynx (may appear as white plaques)
respiratory distress
IMPORTANT POINTS
1. The initial physical findings can be unreliable in ruling out thermal burns to the
upper airway.
2. History of the circumstances of the burn is important to assess the possibility of
airway burns (eg confined space, explosion, flame, steam)
3. If thermal upper airway burns are present, also consider carbon monoxide,
cyanide or hydrogen sulphide poisoning from smoke inhalation.
4. If caustic burns are present, consider other ingestants as well
5. Airway compromise can be delayed but dramatic in onset.
2.8.1 Management of Upper Airways Burns
INITIAL STABILISATION
1. Airway
Complete Obstruction
summon help from the doctor most experienced in airway
management.
Use basic airway opening techniques (eg suction , head position,
oropharyngeal airway, nasopharyngeal airway) and attempt ventilation
via bag valve mask attached to oxygen
Attempt intubation without the use of muscle relaxants initially
If unsuccessful, proceed to emergency surgical airway
Partial Obstruction
Diagnosis based on the presence of stridor, hoarse voice and/or respiratory
distress.
Humidified oxygen
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Notify anaesthetist/surgeon
Transfer to operating theatre accompanied by skilled staff for
examination under anaesthetic/intubation or tracheostomy
Do not transfer the patient to another institution until intubated
Potential Obstruction
Diagnosis based on the presence of sore throat, circumferential neck burns,
sooty sputum, burnt mouth/tongue/nasal hairs or history of fire or
explosion in confined space. Consider intubation.
2. Breathing
Measure respiratory rate, and if inadequate, assist ventilation with bag
valve mask attached to oxygen.
Measure SaO2. If <95% and not requiring assisted ventilation, administer
high flow oxygen ( 100% O2 via non rebreather mask if carbon monoxide
poisoning is a possibility)
3. Circulation
Measure pulse rate, BP and capillary refill
Attach to a cardiac monitor and assess the rhythm
Insert IV cannula
Take blood for FBC, biochemistry
4. Disability
Record a GCS and pupil response. Consider intubation (if this has not already
been done), if GCS 8 or below, to protect the airway.
5. Monitor
- BP, ECG, SaO2
6. Summon
senior doctor with airway skills
DIRECTED HISTORY AND EXAMINATION
Ask about
Event
Circumstances of the burn(eg enclosed area, explosion, steam)
Associated trauma if explosion was involved
Episodes of loss of consciousness (possibly associated carbon
monoxide poisoning or head injury)
Symptoms
stridor/dyspnoea
cough
sore mouth/throat
hoarse voice
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Past History
associated respiratory illnesses (eg asthma)
medications
allergies
medical problems
Look for
Stridor, voice changes, oral or nasal burns, facial or circumferential neck burns,
nature of cough
Tests
Blood gases, Carboxy Hb
DISPOSITION
For complete obstruction with surgical airway in place or partial obstruction:
Notify anaesthetist, ENT surgeon
Notify operating theatres
When all resources are assembled transfer to the operating theatres
accompanied by skilled staff, oxygen, Ambu bag, difficult intubation tray
and surgical airway equipment
For potential obstruction, admit to an Intensive Care Unit
If patient transfer is to occur, consider intubation prior to transfer
IMPORTANT POINTS
1. Intubate early if signs or history suggesting airway involvement in burns.
2. Be prepared for a difficult intubation.
3. Involve the available doctor most experienced in airway management.
2.9 UPPER AIRWAY TRAUMA
DEFINITION
Blunt or penetrating traumas to the neck or face involving elements of the upper
airway.
CAUSES
1. Motor vehicle accidents
2. Assaults
3. Falls
4. Hanging
5. Penetrating injuries
CLINICAL FEATURES
1. Airway obstruction is the greatest concern and can be due to :
collapse of anatomical structures (eg mid face, mandible, larynx)
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foreign bodies
haemorrhage
swelling
Complete Obstruction
no air movement present
until the patient loses consciousness there will be
- grabbing at throat
- paradoxical breathing ie abdomen moves inwards while chest
expands during attempted inspiration
- extensive use of accessory muscles of respiration
- cyanosis
- agitation
Partial Obstruction
still some air movement present
stridor, cough, self posturing (eg sitting upright and leaning forward)
use of accessory muscles of respiration
cyanosis while breathing room air is a late sign of partial upper
airway obstruction
Potential Obstruction
normal air movement
none of the above features, but
swollen face, swollen tongue, sore throat, external neck trauma
IMPORTANT POINTS
1. Fractures of the mandible can disrupt the attachments of the tongue to the
mandible, preventing effective basic airway manoeuvres.
2. Evidence of airway injury in blunt trauma may be very subtle initially,
especially laryngotracheal injuries. Voice changes or dysphagia may be early
signs.
3. Cervical spine injuries have a higher incidence in this setting and must be
excluded.
4. There is often significant haemorrhage associated with these injuries.
2.9.1 Management of Upper Airway Trauma
INITIAL STABILISATION
1. Position Patient
- allow to self posture when able, to maintain airway patency. Hard collar if
cervical spine injury is suspected.
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2. Airway
Complete Obstruction
Summon help from the doctor most experienced in airway
management
Use basic airway opening manoeuvres
Attempt intubation without use of muscle relaxants initially
If unsuccessful, proceed to emergency surgical airway
Partial Obstruction
Based on presence of stridor, hoarse voice and or respiratory distress.
Humidified oxygen
Notify anaesthetist/surgeon
Transfer to operating theatre accompanied by skilled staff for
examination under anaesthetic/intubation/tracheostomy
Do not transfer patient to another facility until intubation has occurred
Potential Obstruction
Based on the presence of sore throat, swollen face, swollen tongue,
external neck trauma. Consider intubation by a doctor experienced in
airway management, especially prior to transfer. Consult with a retrieval
service if necessary.
Mandibular fractures : where the tongue cannot be cleared by special
techniques a towel clip or large suture can be used to retract and
anchor it.
Foreign bodies penetrating the face and mouth should not be removed
and the wound not explored until the patient is in the operating
theatre.
In laryngeal fracture resulting in airway obstruction, needle
crichothyroidotomy is the procedure of choice. Formal
cricothyroidotomy should not be performed as this may further disrupt
the anatomical structures.
The trachea can be intubated directly through the neck in a penetrating
wound.
3. Breathing
Measure respiratory rate. If inadequate, assist ventilation with bag valve
mask attached to oxygen
Measure SaO2. If <95% and not requiring assisted ventilation, administer
high flow oxygen via mask.
Examine for associated pneumothorax or other chest injury.
4. Circulation
Measure PR, BP, and capillary refill
Attach to cardiac monitor and assess rhythm
Insert IV cannula
Take blood for FBC, biochemistry, crossmatch
If shock is present, give crystalloid rapidly
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5. Haemorrhage Control
Reduce fractures immediately, especially if mid third of face is involved
Pack nasopharynx if necessary
Pack or suture other wounds
6. Monitor
- SaO2, BP, ECG
7. Summon
a doctor with airway skills
DIRECTED HISTORY AND EXAMINATION
Ask about :
Event
mechanism of injury
Symptoms
voice changes
painful swallowing
noisy breathing/dyspnoea
Past History
medications
allergies
medical problems
Look for :
stridor
swelling of the neck, palate, tongue
subcutaneous emphysema in the neck or face
laryngeal deformity or tenderness
middle third of face mobility
significant haemorrhage especially nasopharyngeal
Tests
None pre-stabilisation
Once stable, consider :
facial Xrays/CT
CXR
cervical spine Xray
CT neck and larynx if possible
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SPECIFIC TREATMENT
Laryngeal trauma - where there is no clinical evidence of airway compromise, but
there is subcutaneous emphysema due to blunt neck trauma, administer humidified
oxygen and commence IV antibiotics for possible salivary contamination of the deep
tissues of the neck.
DISPOSITION
For complete obstruction with surgical airway in place, or partial obstruction:
1. Notify anaesthetist/ENT or local equivalents
2. Notify operating theatre
3. When all resources are assembled transfer to operating theatre
accompanied by skilled staff, oxygen, suction, bag valve mask system,
difficult intubation tray and surgical airway setup.
IMPORTANT POINTS
1. Always maintain a well prepared crash trolley.
2. Ensure that before intubation the staff, equipment and patient are prepared as
much as time allows.
3. Check all equipment before commencing.
4. If hypoxia occurs, assume tube malfunction or malposition first. If in doubt,
extubate, ventilate, re-oxygenate and re- intubate with a fresh tube.
FURTHER READING
Emergency Medicine, Chris Moulton and David Yates ISBN 0-632 02766-5
Chapter 1 The Principles of Emergency Medicine
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