Airway management in rural ED — RSI, difficult airway, surgical airway

Overview

Airway management failure accounts for 8-15% of potentially preventable trauma deaths. In the rural and remote Australian context, the stakes are amplified: specialist backup is often hours away, retrieval may be delayed, and the rural generalist must execute a full spectrum of interventions, from basic manoeuvres to surgical cricothyrotomy, with limited personnel and equipment.

Core principles:

• Oxygenation is always the primary goal.
• Not every patient requires intubation; basic manoeuvres or supraglottic devices may suffice until a more controlled environment is available.
• Every emergency airway must be assumed potentially difficult; every management plan must include a plan for failure.
• A definitive airway = a cuffed device placed in the trachea below the vocal cords (cuffed ETT or surgical airway).
• Intubation (outside cardiac arrest) is performed as modified RSI, the terms RSI and modified RSI are used interchangeably.

Indications for Airway Intervention

Timing of RSI, Factors to Consider

A functioning prehospital supraglottic airway providing adequate oxygenation may be continued, with replacement deferred until optimal personnel and equipment are available.

Assessment

Anatomical Predictors of Difficult Airway

A reassuring assessment does not exclude difficult airway. Always prepare for failure.

Physiological Predictors of Peri-intubation Risk

• Hypotension: Sedative agents and positive-pressure ventilation reduce preload and can precipitate cardiovascular collapse, fluid resuscitate before RSI; prepare vasopressors.
• Hypoxia: Reduced reserve in obese, pregnant, paediatric, and patients with pre-existing lung disease, maximise preoxygenation.
• Raised ICP: In TBI, laryngoscopy without adequate sedation raises BP and ICP; apnoea causes hypercapnia and further ICP elevation.
• Hyperkalaemia risk with suxamethonium: Contraindicated > 24 hours after extensive burns, prolonged immobilisation, or spinal cord injury.

Investigations

Capnography is the gold standard for ETT confirmation, clinical signs alone (chest rise, air entry, SpO₂) are insufficient and unreliable.

Management

Airway Intervention Spectrum

Escalate stepwise unless immediate advanced airway is mandated:

1. Basic manoeuvres, chin lift, jaw thrust; allow spontaneous positioning if patient is oxygenating (especially trauma/airway injury patients)
2. Adjuncts, oropharyngeal airway (OPA), nasopharyngeal airway (NPA, avoid if base-of-skull fracture suspected), wide-bore suction
3. Supraglottic airway, LMA / i-gel as bridge, temporising, or rescue device
4. Tracheal intubation via modified RSI
5. Surgical airway, when above measures fail or are contraindicated

Modified RSI

Pre-RSI Preparation Checklist

Use a structured checklist before every RSI. Key elements:

Preoxygenation and Apnoeic Oxygenation

• High-flow O₂ via non-rebreather mask (15 L/min) for ≥ 3 minutes; or 8 vital capacity breaths where time is critical.
• In the obtunded patient, assisted BVM ventilation may be required.
• Apnoeic oxygenation: nasal cannulae at 15 L/min maintained throughout laryngoscopy, significantly extends safe apnoea time, particularly important in obese patients, children, and pregnant patients who desaturate rapidly.

RSI Medications

$$\text{Rocuronium RSI dose} = 1.2 \; \text{mg/kg}$$

Vasopressors (prepared before induction, not a substitute for volume):

All sedative agents can cause or worsen haemodynamic derangement, doses are reduced compared to elective intubation. Fluid resuscitation precedes RSI in haemodynamically unstable patients; vasopressors treat vasodilation from sedatives, not shock itself.

Sugammadex

If rocuronium is used and surgical airway is not feasible, sugammadex 16 mg/kg IV can reverse profound neuromuscular blockade. However, this is not a routine rescue strategy, waking a trauma patient is rarely a viable option. Stock sugammadex in rural EDs where rocuronium is used.

Laryngoscopy

• Approximately 60 seconds after NMBD administration, attempt laryngoscopy.
• Video laryngoscopy (VL) is preferred for trauma intubations, superior first-pass success rates. Standard-geometry VL blades (similar to Macintosh) are appropriate for less experienced operators. Extended-angle blades require additional training.
• Direct laryngoscopy (DL) with Macintosh blade: standard fallback for all rural generalists.
• Bougie (gum-elastic bougie / Eschmann introducer): use early when view is suboptimal; angled tip facilitates anterior passage; railroad ETT over bougie.
• BURP manoeuvre: backward, upward, rightward pressure on larynx by assistant improves laryngoscopic view; also termed external laryngeal manipulation.
• C-spine: MILS by dedicated assistant; remove anterior portion of cervical collar while maintaining MILS.
• If first attempt fails: change something (position, equipment, operator, removal of obstructing material), identical repeated attempts are unlikely to succeed.

Attempt Limits and Escalation

• Maximum 3 laryngoscopy attempts per operator; one further attempt by a more experienced operator is permitted.
• BVM or LMA ventilation is performed between every attempt, do not allow progressive desaturation.
• Every attempt risks progressive oedema and airway injury, fewer attempts are often better.

Confirmation of ETT Placement

• Mandatory primary confirmation: sustained EtCO₂ waveform present for ≥ 7 breaths.
• Secondary: bilateral air entry, symmetric chest rise, SpO₂ trend improvement.
• Visualisation of tube passing through cords is unreliable alone.
• Oesophageal intubation = absent sustained EtCO₂ → remove tube immediately → ventilate via BVM/LMA → do not reattempt until SpO₂ improved.
• Document ETT depth at teeth/gums; secure tube; reassess after every patient movement.

Difficult Airway Algorithm

PREOXYGENATION + APNOEIC OXYGENATION
 ↓
TRACHEAL INTUBATION ATTEMPTS (max 3; change technique/operator each attempt)
 ↓ FAIL → Declare "Failed Intubation"
RESCUE AIRWAY: LMA or BVM (max 3 attempts at each; switch if unsuccessful)
 ↓ FAIL → Declare "Cannot Intubate, Cannot Oxygenate (CICO)"
SURGICAL AIRWAY: Scalpel-Bougie-Tube

Surgical Airway, Emergency Cricothyrotomy

Indication: CICO situation, failure of tracheal intubation AND supraglottic/BVM rescue. Once initiated, persist and secure the airway regardless of challenges encountered.

Preferred technique: Scalpel-Bougie-Tube

$$\text{Once committed to surgical airway, persist. Do not abandon the procedure.}$$

Rural requirement: Every rural ED must have a pre-packed surgical airway kit (scalpel, tracheal hook, bougie, 6.0 mm cuffed ETT, syringe, tape/securing device). Rehearse this procedure in simulation at least annually.

Post-Intubation Management

Use a structured post-intubation checklist:

DOPE mnemonic, causes of post-intubation deterioration:

• D, Displacement (ETT right mainstem or dislodgement)
• O, Obstruction (mucous plug, kink)
• P, Pneumothorax (tension, from positive-pressure ventilation)
• E, Equipment failure (disconnect from ventilator → manual ventilation)

Special Populations

Traumatic Brain Injury (TBI)

• Prevent secondary injury: avoid hypotension, hypoxia, and hypercapnia.
• Laryngoscopy without adequate sedation raises BP and ICP, ensure adequate induction agent dose.
• Apnoea causes hypercapnia and raises ICP, minimise apnoea time.
• Post-intubation: target normocapnia (EtCO₂ 35-40 mmHg); MAP > 80 mmHg; SpO₂ ≥ 95%.
• Ketamine: historical concerns about ICP elevation are not supported by current evidence; remains a reasonable choice especially when haemodynamic instability coexists.

Paediatric Patients

• All airway structures proportionally smaller, use age-appropriate equipment.
• Larger occiput: place shoulder roll (not pillow) to achieve neutral alignment.
• Miller (straight) blade preferred in infants.
• Cuffed ETTs are appropriate for emergency trauma intubations in all age groups, including small children.
• Rapid desaturation due to low FRC, preoxygenation and apnoeic oxygenation are critical.

$$\text{ETT internal diameter (mm)} = \frac{\text{age (years)}}{4} + 4$$

$$\text{ETT insertion depth at lips (cm)} = \frac{\text{age (years)}}{2} + 12$$

Obstetric Patients

• Reduced FRC (elevated diaphragm), increased aspiration risk (reflux, reduced lower oesophageal sphincter tone), airway oedema.
• Physiological challenges similar to obese patients.
• Left lateral tilt after 20 weeks to relieve aortocaval compression.
• Early RFDS/retrieval involvement.

Elderly Patients

• Reduced protective airway reflexes, high aspiration risk; act decisively.
• Arthritis restricts mouth opening and neck mobility, may worsen with cervical collar.
• Dentures: remove for intubation; leave in place during BVM ventilation to maintain mask seal; if removed, pack gauze between gums and cheek.
• Absence of teeth simplifies intubation but complicates BVM ventilation.
• Reduce RSI sedative doses by 20-40% (barbiturates, benzodiazepines, other sedatives) to reduce cardiovascular depression.
• Vasopressors must be prepared, hypotension after RSI is common due to physiology and pre-existing medications.

Obese Patients

• Increased tissue mass challenges every technique: mask ventilation, LMA insertion, intubation, and surgical airway.
• Head-up positioning is beneficial; insert OPA/NPA early.
• Hypoxia occurs more rapidly due to higher rates of pre-existing pulmonary disease, lower respiratory compliance, and reduced FRC.
• Apply higher PEEP post-intubation; medication dose modifications may be required.

Airway Burns

Urgent intubation is generally indicated in the presence of:

• Decreased level of consciousness
• Dyspnoea or stridor
• Decreased SpO₂
• Suprasternal, substernal, or subcostal retraction
• Full-thickness facial burns
• Oedema of oral structures or tongue

If signs are absent, continue frequent reassessment, progressive oedema can cause obstruction. Airway management becomes significantly more difficult once obstruction develops. Early intubation may preempt obstruction; consult burns centre via telehealth when time allows.

Direct Airway Trauma

• Patients often spontaneously assume a position of breathing comfort, allow this if oxygenation is adequate; do not force supine positioning.
• Minimise instrumentation; invasive manoeuvres performed as gently as possible.
• Surgical airway equipment must be immediately available.
• Awake tracheostomy by a qualified surgeon is the safest option when available, this resource is often not available in the rural/remote context.
• A multidisciplinary approach prevents exacerbating injury.

Transfer and Retrieval Decisions

Pre-retrieval requirements: The airway must be definitively secured before transport. Intubation in a fixed-wing aircraft is extremely hazardous and should be avoided. Confirm ETT position with CXR before departure. Ensure adequate post-intubation sedation and neuromuscular blockade (if required) are established and ongoing supplies are available for transport duration.

Key Rural Practice Points

Sources

• Royal Flying Doctor Service clinical resources
• CARPA Standard Treatment Manual
• Therapeutic Guidelines (eTG)