Emergency and Critical Care Case Spotlight: Treatment of Smoke Inhalation with High Flow Nasal Oxygen

 

Willow is a 3 year old FI Lab Mix who was admitted to our emergency service after being trapped in a housefire. She was found by a Portland firefighter (from the Munjoy Hill Fire Station) who administer oxygen on site prior to transportation. On presentation she was dyspneic, covered in soot, and had harsh lung sounds on thoracic auscultation.

Intranasal catheters were placed for oxygen administration. Bloodwork showed hypophosphatemia (1.6 mg/dL – suspect secondary to hyperventilation), a mild elevation in ALT (356 U/L), and GGT (16 U/L). Both cornea showed evidence of superficial corneal ulceration, and Willow was coughing up black soot material.

Her owners opted to admit Willow on high-flow oxygen via the intranasal catheters. During her hospitalization Willow also received IV sedation (as needed), IV unasyn, IV fluids, and albuterol inhalant treatment. Willow was hospitalized for a total of 7 days, 6 of which were on high flow oxygen.

After a long 6 days of fighting, Willow was discharged to her owners having been off of high flow oxygen for 24 hours. Her owners and the Portland firefighters involved in her rescue arrived to our Warren Ave location to cheer her on as she was discharged from the PVESC Emergency/Critical Care service. As of this publication Willow has continued to improve at home, and we are so happy for her continued recovery.

Clinically relevant facts:

  • The pathophysiology of smoke inhalation is multifactorial. The progression of clinical signs and prognosis differ depending on present respiratory irritants, thermal heat exposure, particulate matter size, and systemic toxins.
  • Thermal heat damage more commonly impacts the upper airway mucosa, leaving dogs vulnerable to upper respiratory infections (chronically). Dogs with prolonged/high heat exposure causing lower airway thermal damage carry a more guarded prognosis as they are prone to edema-driven upper airway obstruction.
  • Carbon monoxide exacerbates the clinical signs, if present, in smoke inhalation cases. It is rapidly absorbed across the alveolar membrane and has 200-250 x greater affinity for hemoglobin than oxygen. This left shift of the oxygen-hemoglobin dissociation curve causes a secondary cellular hypoxia. Administration of oxygen by first responders is imperative to accelerate the elimination of carbon monoxide and support arterial oxygenation.
  • High flow nasal oxygen delivers more concentrated oxygen than traditional oxygen, and allows many patients to avoid the need for mechanical ventilation.

Authored by: Dr. O’Brien, DVM, DACVECC, Emergency and Dr. Landry, DVM, DACVIM, Neurology