Emergency Department Management of Smoke Inhalation Injury in Adults

Points

• Upper airway injuries are due to thermal burns from heat transfer, while lower airway injuries are secondary to chemical and particulate irritants.
• Airway edema, carbonaceous sputum, soot in the nares or oropharynx, facial burns, and singed nasal hairs all indicate potential inhalation injury.
• The diagnosis and prognostication of the course of inhalation injury is challenging, since much of the damage is not visible upon initial presentation.
• A complete physical examination, including a primary and secondary survey, is essential to rule out other acute injuries.
• Pulse oximetry may be falsely normal despite significant carbon monoxide (CO) poisoning.
• Check a glucose fingerstick, lactic acid level, troponin, pregnancy test, and a chest x-ray in all smoke inhalation victims.
• Consider obtaining an electrocardiogram if there is concern for CO exposure, since CO toxicity increases the risk of dysrhythmias and myocardial ischemia.
• A venous blood gas may be used in lieu of an arterial sample to determine a carboxyhemoglobin level. Levels correlate loosely with symptoms.
• An elevated lactic acid level in a smoke inhalation victim should raise concern for cyanide toxicity.
• Checking a cyanide level is not recommended for management in the ED.
• Consider a trial of noninvasive positive-pressure ventilation for patients with mild symptoms and no contraindications.
• The use of hyperbaric oxygen therapy for CO poisoning is controversial and remains a Level B recommendation. Normobaric 100% FiO2 remains the standard of care.
• Bronchodilators, inhaled epinephrine, inhaled nitric oxide, inhaled heparin, inhaled N-acetylcysteine, and inhaled anticoagulants may all play a role in managing patients with smoke inhalation injuries. Further studies are needed.
• Mechanical ventilation is an independent predictor of mortality and can also worsen lung injury.
• Pneumonia and acute respiratory distress syndrome (ARDS) are both common complications of inhalation injury.
• Up to 33% of burn patients require intubation. Of those, 33% to 54% develop ARDS.
• All patients for whom there is concern for potential inhalation injury should be closely observed in a monitored setting for 24 hours, with a low threshold for intubation.
• The presence of inhalation injury is one of the American Burn Association criteria for burn center referral.

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Pearls

• For suspected cyanide poisoning, hydroxocobalamin 5 g IV should be administered immediately.
• Caution must be used when resuscitating smoke inhalation patients, as over-aggressive IV fluids can worsen airway edema.
• There is no conclusive evidence supporting the use of corticosteroids to reduce airway edema in smoke inhalation victims.
• Endotracheal intubation is indicated for patients with deep burns to the face and neck, blistering or edema of the oropharynx, hoarseness or stridor, or large cutaneous burns greater than 40% of total body surface area.

Table 1. Classification of Inhalation Injury

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Reader Comments

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• 1Enkhbaatar P, Pruitt BA Jr, Suman O, et al. Pathophysiology, research challenges, and clinical management of smoke inhalation injury. Lancet. 2016;388(10052):1437-1446. (Review)  DOI: https://doi.org/10.1016/S0140-6736(16)31458-1
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• Buckley NA, Juurlink DN, Isbister G, et al. Hyperbaric oxygen for carbon monoxide poisoning. Cochrane Database Syst Rev. 2011Apr 13(4):CD002041. (Systematic review; 6 trials, 1361 patients)  DOI: https://dx.doi.org/10.1002/14651858.CD002041.pub3
• Wolf SJ, Maloney GE, Shih RD, et al. Clinical policy: critical issues in the evaluation and management of adult patients presenting to the emergency department with acute carbon monoxide poisoning. Ann Emerg Med. 2017;69(1):98-106. (ACEP Clinical Policy)  DOI: https://doi.org/10.1016/j.annemergmed.2007.10.012