Have a Low Threshold for Intubating a Patient with an Inhalation Burn Injury
Richard Wong She MBCHB
James H. Holmes IV MD
A burn patient with an inhalation injury has twice the mortality rate of a similar burn patient without an inhalation injury. Initial presentation may be essentially asymptomatic because time (and resuscitation fluid) is required to generate the edema and alveolar damage, which will manifest as progressive airway obstruction and disturbances in pulmonary function. The mainstay of treatment for inhalation injuries involves securing the airway prior to obstruction and maintaining ventilation while minimizing lung damage. Inhalation injury can result from a combination of three mechanisms. First, direct thermal injury to the upper airway can be caused by superheated gases or aspiration of hot liquids. Hot liquids result in rapid edema formation and require emergent intubation if suspected. By contrast, superheated gases result in relatively gradual edema formation. Second, products of combustion can dissolve in the mucus of the lower airway, resulting in a chemical pneumonitis and alveolar damage, which develops over hours to days. Finally, systemic poisoning can result from the absorption of carbon monoxide (CO). This poisoning should be suspected in all inhalation injuries. A carboxyhemoglobin level should be measured on initial evaluation of the patient. Humidified 100% oxygen is the treatment of choice because it decreases the half-life of carboxyhemoglobin from 250 minutes on room air respiration to around 40 minutes. There is a limited role for hyperbaric oxygen. Supplemental oxygenation should continue for up to 48 h after normalization because there can be delayed release of CO from the intracellular cytochrome system.