When should bronchoscopy be performed in a patient with a fire‑related inhalation injury?

Bronchoscopy Timing in Fire-Related Inhalation Injury

Perform flexible bronchoscopy immediately upon intubation in patients with suspected inhalation injury, as it is the gold standard for diagnosis and its findings directly predict morbidity, ICU length of stay, duration of mechanical ventilation, and risk of acute lung injury. 1, 2, 3

Indications for Immediate Bronchoscopy

Bronchoscopy should be performed as soon as the patient is intubated in the following scenarios:

• Patients already intubated for severe respiratory distress, altered mental status, or airway protection 1, 2
• Suspected inhalation injury based on fire in enclosed space, facial burns, soot around nose/mouth, singed nasal hairs, carbonaceous sputum, dysphonia, wheezing, or stridor 1, 2
• High-risk burns including deep circular neck burns, whole face involvement, or total body surface area ≥40% 1

Critical Safety Consideration

Never perform bronchoscopy in non-intubated patients with suspected inhalation injury, as the procedure itself can precipitate acute airway obstruction from progressive glottic edema 1, 2. This is a common and dangerous pitfall.

Diagnostic Value and Prognostic Significance

Bronchoscopic findings correlate directly with clinical outcomes:

• Severity of mucosal damage predicts acute lung injury risk: Grade 1 (superficial) = 4% ALI risk, Grade 2 (moderate) = 33% ALI risk, Grade 3 (deep) = 77% ALI risk 3
• Bronchoscopy has 79% sensitivity and 94% specificity for diagnosing inhalation injury when compared to histologic gold standard 4
• Bronchoscopy is more reliable than clinical findings, chest X-ray, or arterial blood gases for diagnosis 1, 2

Important Limitation

Bronchoscopy only assesses the proximal airway and does not provide comprehensive analysis of distal pulmonary injury 2. Normal bronchoscopy findings do not exclude inhalation injury 2.

Therapeutic Bronchoscopy Considerations

Sequential therapeutic bronchoscopy may be beneficial in intubated patients:

• Prophylactic sequential bronchoscopy (performed every 2-3 days) showed statistically significant reduction in morbidity (23% vs 60%, p=0.04) compared to single diagnostic bronchoscopy 5
• Removes carbonaceous material, casts, and viscous secretions that can cause airway obstruction and respiratory failure 6, 7
• Trends toward fewer antibiotic days (4.5 vs 9.3 days) and shorter mechanical ventilation duration (5.1 vs 6.7 days), though not statistically significant in small trial 5

Delayed bronchoscopy (days 3-7) may be necessary if secretions accumulate, as viscous sputum mixed with soot can cause complete bronchial obstruction, atelectasis, and pneumonia 6, 7.

Special Circumstance: Airway Fire

After an airway fire during intubation, rigid bronchoscopy (not flexible) should be employed to search for endotracheal tube fragments and assess extent of thermal injury 1.

Monitoring Strategy for Non-Intubated Patients

For patients with facial/neck burns or suspected inhalation injury who do not meet immediate intubation criteria:

• Continuous high-dependency monitoring with frequent airway assessments 1
• Head-up positioning and nil-by-mouth status 1
• Early burn center specialist consultation 1
• Regular reassessment for progressive airway edema 1, 2
• Do not perform bronchoscopy until patient is intubated if deterioration occurs 1, 2