Accidental nitric acid gas exposure and respiratory effects

Abstract

Nitric acid also known as aqua fortis is a highly strong corrosive mineral acid. Accidental exposure to nitric acid inhalation can be fatal. We will share our experience on successful management of a patient developing respiratory insufficiency subsequent to nitric acid inhalation. A 46 years old nonsmoker male patient was admitted to the emergency department (ED) with the complaint of difficulty in breathing and cough. Two days prior to being admitted to the ED an accident occurring in his workplace caused dispersion of nitric acid . He remained in the closed environment for approximately 10 minutes. Afterwards mild symptoms of dyspnea and coughing started that progressed causing him to apply to the hospital for help.Upon admittance to the ED he had severe stridor and signs of bronchospasm with hypoxemia and dspnea. Immediate treatment was initiated with intra venous Methyl-prednisolone 120 mg, N-acetyl cysteine (NAC) 1200 mg enteral and bronchodilators. Noninvasive mechanical ventilation (NIV) was initiated. Within four hours the respiratory rate was normal with 5 lt oxygen with nasal mask. The treatment was continued at the ward and at the end of 1 week of treatment he did not require any further oxygen supportive treatment and there was no difficulty in breathing with normal lung sounds on auscultation. Follow-up at the outpatient clinic showed complete clinical and radiological resolution.Nitric acid inhalation may not cause symptoms immediately after exposure. Management in our case with NAC, corticosteroids, and bronchodilators seemed to be helpful. Furthermore, supportive treatment in the form of oxygen inhalation with noninvasive ventilation may have contributed to the rapid resolution of the patient.