Acute lung injury secondary to nitric acid inhalation: a case series

Introduction: Nitric Acid is a strong oxidizing agent used in industrial factories to dissolve metals and ingredients for organic compounds. Once inhaled, it is highly corrosive to the respiratory tract.

Presentation of Cases: Three patients who worked in the same chemical factory consulted for progressive dyspnea due to nitric acid inhalation. All patients were successfully treated with steroids and supportive management.

Discussion: Chemical agents with low water solubility produce delayed symptoms which leads to delayed management and prolonged exposure. Nitric acid is a low water soluble agent and development of symptoms may be delayed for 15 to 30 hours, while pulmonary edema may develop over 24 hours.Symptoms of inhalation of nitric acid include irritation of the nose, sore throat, cough, chest tightness and dyspnea. Severe inhalation of nitric acid can lead to pulmonary edema presenting with increasing shortness of breath, wheezing, chest tightness and cough. Nitric acid inhalation rarely causes systemic toxicity. There is no therapeutic intervention for pulmonary edema and most cases of nitric acid inhalation injury resolve spontaneously.

Conclusion: Supportive care is the primary management of nitric acid inhalation. Avoidance of exposure and wearing of protective gear is important to avoid acute lung injury.