Outcome of acid ingestion related aspiration pneumonia

The objective of this study is to assess the incidence and long-term results of a rarely discussed medical problem -- aspiration pneumonia resulting from the intentional ingestion of acid.

The medical records of 370 patients treated at one tertiary care institution for corrosive acid injury during a 12-year period were reviewed retrospectively. The study subjects included any patients who were found to have acid ingestion related aspiration pneumonia confirmed by chest film within 24h of injury. All available data of these patients with or without aspiration pneumonia were analyzed.

Of the 370 patients with corrosive acid injury, 15 (4.2%) had acid-aspiration pneumonia which was related to their intentional ingestion of a strong acid, hydrochloric acid (pH<1). The data for 14 patients with aspiration pneumonia and 268 without aspiration pneumonia was complete and available for analysis. Patients with aspiration pneumonia were found to be significantly older (52.2+/-6.2 to 41.7+/-0.9 years old, P=0.017), had a higher incidence of nasogastric tube irrigation (35.7-6.0%, P=0.000), had more conscious disturbance (50.0-17.5%, P=0.016), and required more endotracheal tube intubation (50.0-3.0%, P=0.000). Aspiration pneumonia was found to significantly increase the mortality rate in acid injured patients who required emergency abdominal surgery (87.5-32.0%, P=0.000) and in those who did not (28.5-5.1%, P=0.05). Two of the six survivors of aspiration pneumonia later developed laryngeal sequelae.

Aspiration pneumonia rarely occurs as a consequence of acid ingestion. When it does occur, it greatly increases the mortality rate of those involved. For those who survive, physicians can expect some laryngotracheal sequel in long-term follow-up.