Introduction
This topic covers acute poisoning by corrosive substances, meaning strong acids and strong alkalis that cause immediate chemical burns of the mouth, pharynx, oesophagus and stomach. For the exam you need the definitions, why alkalis and acids behave differently, the clinical grading of injury, the emergency steps (especially airway control) and the late complications, mainly oesophageal stricture and perforation.
Circumstances of exposure and early complications
Most corrosive ingestions in adults are intentional self-harm, while in children they are usually accidental, from household products left in unlabelled containers. Injury depends on the agent, its concentration, the amount, the physical form (solid, liquid, granules) and how long it stays in contact with tissue. Early complications that can threaten life include:
- Airway obstruction from oedema of the larynx and supraglottic tissues, which can develop within hours
- Shock, from fluid loss, bleeding, sepsis or a vagal reaction
- Cardiac arrest, most often from severe acidosis, electrolyte disturbance or hypoxia
- Aspiration of the corrosive into the airways, causing chemical pneumonitis