Severe lung injury following inhalation of nitric acid fumes

Abstract

Objective: We present a rare case of survival following inhalation of nitric acid fumes and its decomposi tion products, which resulted in severe pulmonary edema and Acute Respiratory Distress Syndrome (ARDS). Successful outcome followed ventilatory support and use of steroids. Design: Case report. Setting: Terti ary-level medical intensive care unit. Patient: A single case of inhalation of nitric oxide fumes. Interven tion: Ventilatory support and addition of steroids. Measurement and main results: Improvement and discharge. Conclusion: Inhalation of nitric acid fumes and its decomposition gases such as nitrogen diox ide results in delayed onset of severe pulmonary edema deteriorating into ARDS. Intensive respiratory management, ventilatory support, and steroids can help in survival.

Acute lung injury following exposure to nitric acid

“…Toxic exposure to nitrogen dioxide has generally occurred in four circumstances: Exposure to silo gases, welding, combustion of nitrogen-containing materials, and spills of nitric acid. [ 1 ]…”

“…This delayed effect has been well described in almost all cases of nitric acid and nitrogen dioxide inhalation injury reports. [ 1 ] Hajela et al, have reported three deaths owing to rapidly progressing pulmonary edema of delayed onset after inhalation of fumes due to accidental nitric acid exposure.…”

“…Use of high-frequency ventilation and reduction of the mean and peak airway pressures have been recommended. [ 1 5 ]…”

“…after exposure the patient can develop bronchiolitis obliterans. [ 1 ] Most such cases resolve. As most of these incidents have been sporadic and accidental, follow-up of the cases is not thorough.…”

“…Inhalation injuries occur as a result of asphyxiation, local irritation, toxic absorption, or allergy. [ 1 ] Irritant gases when inhaled in high concentrations injure the respiratory tract by causing acute inflammation, the main site of injury depending on the solubility of the gases. More soluble gases exert maximal effect, more proximally in the respiratory tract; and less soluble gases like nitric acid fumes exert maximal effect more distally.…”