Airway
kills fast
Common cause of avoidable mortality is not securing the airway
- recognise the need for an airway
- secure the airway.
- recognise an incorrectly placed or a displaced airway
- recognise the need for ventilation
- prevent aspiration
Problem
Recognition
Compromise may be
- sudden and complete
- insidious and partial
- progressive and/or recurrent.
--> frequently reassess.
Unconscious are at particular risk of hypoxia and hypercarbia
- intubation provides an airway, delivers O2, supports ventilation
and prevents aspiration.
Aspiration should be anticipated
--> immediate suction, role entire patient to lateral position.
Objective
Signs Remove the helmet. Talk to the patient first
- a positive and appropriate response indicates a patent ventilating
airway with brain perfusion.
- otherwise there is airway/ventilation compromise or altered
consciousness. Inspect
Obtunded (hypercarbia), agitated (hypoxia - don't presume
intoxication).
Cyanosis (hypoxia)
Refusing to lie down.
Accessory muscle use.
Noisy breathing is obstructed.
Snoring, gurgling crowing (stridor) - partial occlusion.
Hoarseness - dysphonia - functional laryngeal obstruction.
Neck haematomas - can obstruct
Material in mouth - blood, teeth, vomitus Palpate
Ensure trachea is midline
Maxillofacial
trauma
Mid-face #/dislocation compromises the naso & oropharynx.
- associated haemorrhage, secretions and teeth cause additional
problems.
Mandibular #s (esp bilateral) causes loss of support
--> obstruction in the supine position
Neck
trauma Penetrating injury
- can cause haemorrhage, airway displacement & obstruction
--> urgent surgical airway required.
--> operative control may be required.
C-spine immobilization unnecessary in penetrating trauma; may delay
correct care Laryngeal/trachea disruption
Initially these pts may maintain patency & ventilation
- can be accompanied by bleeding into the tracheobroncheal tree
- if compromise suspected --> definitive airway
- can be obstructed from outset --> urgent definitive airway.
Insert the ET tube cautiously else the existing injury may extend.
- if patency being lost, a surgical airway is usually indicated.
Laryngeal
trauma Noisy breathing indicates
partial/threatened airway
Absence suggests obstruction.
In an unconscious patient, laboured resps may be the only feature. Laryngeal fracture
Rare but can be life threatening.
- triad of hoarseness, subcutaneous emphysema, palpable fracture.
If totally obstructed
--> attempt intubation, flexible endoscopic guidance if
available.
--> if unsuccessful, emergency tracheostomy (difficult and may
invoke bleeding and take time)
--> surgical cricothyroidotomy may be life-saving, although not
preferred
CT can identify subtle larynx fractures. Penetrating trauma
Requires immediate attention due to risk of transection or occlusion
- oesophageal, carotid and jugular injury may be associated.
Securing an Airway
1. Provide supplemental oxygen before and after airway
management.
2. Maintain C-spine protection Recognise difficulty
Beard, poor dentition, short mandible, tooth loss
Poor mouth opening / poor view
- Mallampati designed for pts sitting up spontaneously opening
mouths
Oropharyngeal bleeding
Tongue obstruction
- readily corrected with chin lift and
jaw thrust
- maintain with oropharyngeal or
nasopharyngeal airway
Multilumen oesophageal airways are sometimes used by
prehospital staff
- one communicates with trachea (ventilated), one with oesophagus
(ballooned).
- remove it after appropriate assessment.
- similarly check position
of any tube placed in the field, after transport.
Laryngeal masks Are not a
definitive airway.
- difficult without training and role in trauma not defined.
- if in place, decide whether to continue or remove & intubate.
Definitive Airway Tubed with
cuff inflated and oxygen-rich assisted ventilation, secured with
tape
Three types:
1. Orotracheal intubation
2. Nasotracheal intubation
- requires breathing
- avoid in pts with Battle sign, raccoon eyes rhinorrhea, otorrhoea,
midface #s.
3. Surgical airways (see below)
Once placed supplemental sedation, analgesics and muscle relaxants
may be required. C-spine injury is of major
concern during intubation.
May need rapid sequence
intubation in the awake patient in an acute setting.
Decision to place depends on: 1.
Expertise
of the doctor
2. Need for protection
- impending or potential compromise
- eg inhalation / facial injury, sustained seizures
- eg blood / vomit aspiration risk
- eg retropharyngeal haematoma, larynx/trachea injury, stridor
3. Need for ventilation
- apnoea (paralysis, unconscious GCS<=8)
- inadequate respiration (tachypnoea, hypoxia, hypercarbia,
cyanosis)
4. Clinical findings
-
urgency, need and type dictated by scenario
- pulse oximeter may help
decision.
- so might this algorithm:
Indications for definitive airway
Resp insufficiency
Airway obstruction
GCS<=8
Severe maxillofacial trauma
- can obstruct, bleed into airway, distort anatomy complicating
intubation
Thermal airway injury
- suspect in all burns
- esp if singed nasal hairs, carbonaceous sputum, face burns.
- intubate, do not wait until progression of oedema, hoarseness and
stridor.
Persistent agitation.
- rule of 3: if physically or verbally assaults the team 3 times,
intubate.
Large / expanding neck haematoma
Penetrating airway injury
Airway
Algorithm
Severe maxillofacial injury
Attempt intubation
--> surgical airway if unable
Apneic
Orotracheal intubation with in-line immobilization
--> surgical airway if unable.
Breathing
Nasotracheal / orotracheal intubation with in-line immobilisation
--> pharmocologic adjunct if unable
--> surgical airway if still unable
Rescue Techniques
LMA
- does not protect airway
- may be useful temporizing measure when intubation unsuccessful
- do not use when massive maxillofacial trauma or pregnancy >16w
Video Laryngoscopy
- fibreoptic visualization of pathway
- less movement of c-spine
- useful in the morbidly obese; limited neck mobility; any difficult
airway
Flexible fibreoptic bronchoscopic-assisted intubation
- advanced technique
- ETT preloaded over flexible bronchoscope, intubated
Surgical Airways Indicated when unable to intubate the trachea
- eg glottis oedema, fracture of the larynx, severe oropharyngeal
haemorrhage.
Surgical cricothyroidotomy is usually preferred to tracheostomy
- less bleeding & quicker. 1. Jet insufflation
- can be useful short-term in emergency situations
- not if pt has abnormal pulmonary function or significant chest
injury.
- lower flow to prevent barotrauma in persisting foreign body
obstruction of the glottic region.
- never seen it done though... 2. Cricothyroidotomy
- may need to briefly remove collar and immobilise neck during
procedure.
3. Emergency tracheostomy - less commonly used
- may be necessary if tracheal disruption, direct airway injury /
larynx #
- preferable in children as cricothyroidotomy can damage larynx.
4. Percutaneous
tracheostomy
- highly selective, only by those with substantial non-urgent case
experience
- otherwise best to use open techniques with optimal control in
emergency. Airway Decision Scheme
2. If showing respiratory effort
--> pass a nasotracheal tube (? - really?; never seen it) If not
--> endotracheal tube under in-line immobilisation
3. If unable to intubate /
contraindicated
--> cricothyroidotomy
Key
Questions
1. Does patient need to be intubated?
2. How quickly?
3. Will it be challenging?
4. What is the best method?
5. What is the back-up plan if it fails?
Oxygenation
All patients
Tight fitting O2 reservious face mask
- flow rate 11L/min.
Nonrebreather masks can improve concentation.
Pulse oximetry
Especially important for transport, or difficulties with airway
predicted. Ventilation
Problem
recognition
Ventilation depends on the airway, ventilatory mechanics and the
NCS.
If clearing the airway does not help breathing, find another source.
Direct trauma
--> pain with rapid shallow resps and hypoxia.
--> especially dangerous in those with preexisting chest
problems.
Head injury
--> abnormal breathing patterns.
C-spine injury
--> diaphragmatic breathing and hypoxia
--> or paralysis requiring assisted ventilation.
Difficult to bag-valve mask if:
- facial hair
- midface #s
- combative pt
--> secure airway
Objective
signs Inspect
Asymmetrical chest excursion
- eg flail splinting (immediate threat)
Tachypnoea may represent 'air hunger'. Auscultate
Decreased or absent breaths
- eg intrathoracic injury Pulse oximetry
Essential.
Helps know sats, perfusion, but does not assure adequate
ventilation.
Management 2 person bag-valve-masking
is better than one.
- one person holds with jaw thrust for a good seal
- another squeezes bag every 5 seconds with both hands.
- flow rate 12L/min
- assess success by chest expansion. Intubated ventilation
- proceed with positive pressure breathing.
- either volume or pressure regulated respirator.
- be alert for complications (eg pneumothorax).
Difficult
airway
Principles
of
airway Mx
· Assess
· Intervention
Early
intubation
· ¯ LOC (<10)
· Craniofacial
injuries
· Burns
· Chest injury
· Shock
· Multitrauma
v Use drugs only if
can be
confident of controling airway & ventilation