Should hyperbaric oxygen (HBO) be administered to a patient with an inhalation injury before intubation?

Management of Inhalation Injury: Airway Prioritization Before Hyperbaric Oxygen Therapy

Endotracheal intubation should be performed without delay before considering hyperbaric oxygen therapy in patients with inhalation injury who show signs of airway compromise. 1

Initial Airway Assessment

Immediate airway evaluation is critical in inhalation injury patients. Intubate without delay if any of these signs are present:

• Airway obstruction
• Altered consciousness (GCS ≤ 8)
• Hypoventilation or hypoxemia
• Stridor
• Use of accessory respiratory muscles
• Blistering or edema of the oropharynx
• Deep burns to face or neck 1

Oxygenation Management

1. Pre-intubation:

   • Apply high-concentration oxygen via tight-fitting facemask capable of delivering CPAP (5-10 cm H₂O)
   • Apply nasal oxygen at 5 L/min while awake, increasing to 15 L/min after loss of consciousness
   • Consider HFNO (high-flow nasal oxygen) at 30-70 L/min if available 1

2. During intubation:

   • Maintain nasal oxygen at 15 L/min during intubation attempts
   • Use facemask ventilation with CPAP between attempts if hypoxia occurs 1

3. Post-intubation:

   • Target normal oxygenation (PaO₂ 70-90 mmHg or SaO₂ 92-97%)
   • Avoid both hypoxemia and hyperoxemia
   • Maintain normoventilation (PaCO₂ 35-40 mmHg) 1, 2

Intubation Technique

• Use rapid sequence induction with full neuromuscular blockade
• Select the largest endotracheal tube available (usually 8 or 9 mm) to decrease airway resistance
• Confirm placement with waveform capnography immediately after intubation 1
• Consider video laryngoscopy for difficult airways 1

Ventilation Strategy

• Use lower tidal volumes (6-8 mL/kg)
• Apply slower respiratory rates
• Use shorter inspiratory time (inspiratory flow rate 80-100 L/min)
• Allow longer expiratory time (I:E ratio 1:4 or 1:5)
• Monitor for auto-PEEP and breath stacking 1

Role of Hyperbaric Oxygen Therapy

Hyperbaric oxygen therapy (HBO) should only be considered after securing the airway in patients with:

• Carbon monoxide poisoning
• Cyanide exposure
• Severe smoke inhalation with persistent hypoxemia despite conventional management 3

Common Pitfalls to Avoid

1. Delayed intubation: Waiting too long can lead to complete airway obstruction due to progressive edema
2. Hyperventilation: Avoid excessive ventilation which can cause hypotension and auto-PEEP
3. Excessive tidal volumes: Can worsen barotrauma and air trapping
4. Ignoring auto-PEEP: If patient deteriorates, disconnect from ventilator to allow passive exhalation
5. Premature HBO consideration: Securing the airway takes absolute priority over HBO therapy

Special Considerations

• Mild hypoventilation (permissive hypercapnia) may be necessary to reduce barotrauma risk
• If auto-PEEP causes hypotension, assist exhalation by pressing on chest wall after disconnecting ventilator circuit
• Consider sedation to optimize ventilation and decrease ventilator dyssynchrony
• Continue inhaled bronchodilator treatments through the endotracheal tube if indicated 1

The management of inhalation injury requires a systematic approach with airway security as the absolute first priority. While hyperbaric oxygen may have benefits for specific toxicities, it should never delay definitive airway management in patients showing signs of respiratory compromise.