FRCA Notes

Airways in the Trauma Patient

The curriculum asks for 'the anaesthetic management of potential threats to the airway, including... blunt and penetrating trauma'.

This includes 'advanced airway management skills in trauma patients [including those with suspected unstable cervical spine]'.

Resources

  • The goals of airway management in the major trauma patient are to:
    • Maintain oxygenation and ventilation
    • Protect the lungs from aspiration of gastric contents or blood
    • Facilitate safe patient transfer, be it intra- or inter-hospital transfer
    • Facilitate emergent or urgent surgical intervention
    • Control physiological parameters within tight boundaries in certain cohorts e.g. traumatic brain injury

Direct traumatic effects Indirect effects of trauma Intervention-related
Disrupted soft tissue and bony architecture Swelling Neck-immobilisation with collar/blocks/tape
Blood | secretions | foreign body in the airway ↓ consciousness leading to loss of airway/aspiration Manual in-line stabilisation
Unstable C-spine Agitation e.g. pain, hypoxia, intoxication Time pressure
Physiological derangement e.g. hypoxia Difficult to assess airway e.g. due to immobilisation Ad hoc team in non-theatre environment


  1. Actual, or impending, airway compromise
  2. Ventilatory failure
  4. Reduced GCS
    • Combative or agitated patients (especially after TBI)
    • To facilitate regulation of ICP via PCO2
    • Humanitarian for analgesia e.g. severe burns, traumatic amputation
  5. Anticipated clinical course requiring intubation e.g. CT, theatre

  • General issues affecting all modes of airway intervention include:
    • Lack of patient co-operation
    • Risk of aspiration
    • Risk of 'can't oxygenate' scenario
    • C-spine injury

  • The severely injured trauma patient should ideally undergo RSI and intubation, but depending on the case's individual factors theoretical options include:
Non-intubation Oral intubation Front of neck
Supraglottic device RSI → intubation Retrograde intubation
Inhalational induction → intubation Awake tracheostomy
Awake tracheal intubation Awake cricothyroidotomy

Supraglottic devices

  • Benefit from simplicity
  • Do not secure the airway

  • Second-generation devices may be appropriate in certain circumstances as the primary albeit temporary airway management device
  • For example, to tamponade upper airway bleeding and facilitate resuscitation prior to intubation
  • Intubating LMAs may also be useful in patients with high suspicion of C-spine injury to provide a channel for oxygenation, allowing more time, and intubation using a flexible 'scope

RSI

  • Intubation may be complicated by the presence of MILS and cricoid pressure
  • Facial injury may impair effective pre-oxygenation
  • Induction agents may exacerbate existing cardiovascular instability

  • Evidence suggests videolaryngoscopy has a higher first pass success rate for patients with immobilised C-spines vs. direct laryngoscopy (BJA, 2021)

Inhalational induction

  • Facial injury may impair mask seal
  • Slow induction exacerbates aspiration risk
  • Possible airway obstruction from oedema or blood

  • (Unlikely to ever be used but came up as a potential answer in a past question, so is included here for completeness)

Awake tracheal intubation

  • Issues:
    • Presence of blood/secretions may lead to inadequate topicalisation with LA or distort/preclude airway anatomy
    • Abnormal anatomy may make awake intubation technically difficult
  • In a RCT of VL vs. fibrescopic intubation in patients with C-spine immobilisation, VL had a greater first pass success rate and a shorter time to intubation (Anaesthesia, 2023)

  • Gastric volume in the trauma patient is related to the interval between the last meal and the time of injury
  • There is little evidence that prolonged fasting time pre-procedure reduces the risk of aspiration i.e. little benefit in delaying surgery
  • The use of opioids exacerbates the effect of trauma on gastric emptying by further decreasing gastric transit
  • Evidence suggests the risk of aspiration may be less than the risk of I&V-induced haemodynamic compromise or hypoxia during airway management

Preparation

  • Airway-related roles should be allocated by the trauma team leader
  • Consider need for additional support from other anaesthetists, ENT or OMFS teams
  • Prepare equipment as appropriate; plan for a difficult intubation
  • Use intubation checklist where appropriate

Airway assessment

  • A thorough airway assessment is often difficult due to factors such as limited access, poor patient cooperation and time pressure
  • An 'A' assessment should form part of the primary survey using standard metrics e.g. airway noise, presence of fluid or foreign body in the oropharynx etc.
  • A patient with low GCS should be presumed to have a threatened airway and intubation expedited
  • Airway assessment mnemonics are recommended by some e.g. LEMON by ATLS
  • Checking the patients existing hospital records (if patient details known) may help elucidate particular risks e.g. previous neck radiotherapy, previous intubation grades, previous C-spine surgery
  • Anecdotally patients with significant injuries often arrive I&V; the position of the ETT should be checked as standard e.g. ETCO2, chest movement, depth of ETT insertion, adequate securing of the tube

C-spine

  • Patients with major trauma often undergo C-spine stabilisation i.e. hard trauma mattress, blocks and tape
  • This will need to be safely removed during intubation and manual in-line stabilisation (MILS) performed instead
  • MILS
    • Permits greater mouth opening than a rigid collar
    • Requires a dedicated assistant
    • May increase risk of iatrogenic harm (C-spine injury) if performed incorrectly
    • Lacks high-quality outcome evidence; some evidence to suggest it increases subluxation of damaged C-spine segments
    • Increases difficulty of laryngoscopy and intubation (increases proportion of Grade 3/4 views) as with other C-spine immobilisation techniques

  • Airway manouevres
    • Both chin-tilt and jaw thrust cause greater cervical spinal segment angulation than DL, with jaw thrust doing less so than chin-lift
    • Application of a facemask for oxygenation can cause a greater degree of anterior-posterior cervical displacement than DL
    • Correctly applied cricoid force causes only minimal effects on the C-spine, but evidence of safety in those with C-spine injury is lacking

  • Choice of intubating device
    • VL causes less displacement of cervical structures than DL
    • The benefit of awake tracheal intubation over VL with regards C-spine injury is not proven; VL may be non-inferior
  • Overall the risk of secondary spinal cord injury during airway manipulation appears low (<0.5%) if appropriate care is taken, with little evidence of direct causation between intubation and neurological injury

Intubation

  • The timing of intubation will depend on patient- and trauma-specific factors, which prevents over-generalisation about when to perform it as part of a trauma scenario
  • A (modified) RSI approach is almost universally used to minimise risk of gastric aspiration
  • Number of intubation attempts correlates with airway complication rates, so first-pass success is vital

  • Drugs
    • Ketamine (1-2mg/kg) is typically the preferred induction agent, even in TBI, although propofol is a viable alternative
    • Rocuronium (1.2mg/kg) is typically the preferred NMBA; although suxamethonium (1mg/kg) is a viable alternative it is rarely used
    • High-dose opioids (e.g. fentanyl 2-3μg/kg) or IV lidocaine (1-1.5mg/kg) may be used to further blunt the haemodynamic response to larygnoscopy, which may be useful in certain patients e.g. intra-cranial pathology

  • Airway equipment
    • VL reduces the overall risk of failed intubation vs. DL (Cochrane review) and should be used first-line
    • Hyperangulated blades should be available
    • Preformed stylets or bougies should be available and consider using during first attempt
    • HFNO may prove useful by prolonging apnoea time, recruiting lung units with CPAP and relieving airway obstruction, although it is often not available
    • Awake intubation in the trauma patient requires a cooperative patient, experienced operators and the ability to perform an emergency surgical airway rapidly; it should be done in theatres

  • Delayed-sequence induction (DSI)
    • DSI aims to balance the risk of aspiration against the risks of haemodynamic compromise, failed intubation and hypoxia, which can occur if RSI is attempted in under-resuscitated and non-optimised patients
    • It involves using sedation ± analgesia (often with ketamine) to facilitate proper pre-oxygenation, positioning etc.
    • It is then followed by an anaesthetic dose of an induction agent and NMBA as standard, before proceding with intubation

  • Consider head-up or reverse Trendelenburg positioning to aid (pre-)oxygenation, especially in those with TBI

Facial fractures

  • Facial fractures indicate high-energy trauma and rarely occur in isolation
  • Issues include:
    • Often active airway bleeding
    • Soft tissue, teeth or bone fragments obstructing the airway
    • Trismus due to distorted bony or soft tissue anatomy
    • Laryngotracheal compression from anterior haematoma
    • Fracture displacement (see below)
    • Dural tears and CSF leak (with Le Fort III fractures)
    • Failure of common airway manouevres due to aberrant anatomy

  • Unstable mid-face or lower face fractures may undergo posterior displacement of the fracture segment, which can cause:
    • Airway obstruction
    • Malocclusion
    • Oesophageal injury
    • Pneumomediastinum
    • Subcutaneous emphysema

  • The awake patient should be positioned as is comfortable
    • This may include sitting upright to displace fracture segments anteriorly and relieve airway obstruction
    • Bleeding may be significant so lateral position may help reduce pooling in the airway

  • High risk of difficult or failed airway management
    • Consider management in theatre environment
    • Consider MDT (ENT, OMFS) on standby to perform emergency airway access procedures e.g. retromolar, submental or retrograde intubation or trans-tracheal jet ventilation