Dose-Dependent Pulmonary Injury Following Nitrogen Dioxide Inhalation From Kinepak^™ Detonation

Nitrogen dioxide (NO₂) is a pulmonary irritant produced as a byproduct of bacterial anaerobic metabolism of organic materials, and is also produced as a byproduct of explosive detonations. Significant NO₂ exposure results in free-radical-induced pulmonary injury that may be delayed up to 3-30 h after exposure and can progress to acute respiratory distress syndrome (ARDS) and death. Here we present a case series of 3 patients with dose-dependent pulmonary injury consistent with NO₂ inhalation following exposure to fumes from detonation of an ammonium nitrate/nitromethane (ANNM) explosive device.

Three individuals presented to the emergency department over the course of 16 h, beginning approximately 16 h after exposure to fumes from an ANNM explosive device. Patient 1, with the most significant exposure, developed ARDS necessitating intubation and mechanical ventilation. Patient 2 exhibited hypoxia and findings concerning for diffuse airway inflammation, but ultimately required only supplemental oxygen. Patient 3, with the least exposure, had imaging abnormalities but required no intervention. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Respiratory distress is a common presenting complaint to the emergency department. Because of the delayed presentation and the potential for progressive worsening of symptoms associated with NO₂ exposure, it is important that emergency physicians be aware of the multiple potential means of exposure and consider this diagnosis in the proper clinical context. Patients with suspicion of NO₂-related lung injury should undergo more extended observation than their initial clinical presentation may suggest.