Caustic Soda is “any substance that is destructive to living tissue; exerting a burning or corrosive effect” (Anderson et al, 2002). It is a common term used for acid and alkali burns, although caustic soda itself is a strong alkali called sodium hydroxide. There are many substances that are caustic including
- Sodium hydroxide
- Sodium hypochlorite
- Hydrochloric Acid
- Sulphuric Acid
- Batteries (alkali)
These are all found in household products.
WHO AND WHY
Over 90% of childhood ingestions are ACCIDENTAL.
- Males ingest more frequently than females
- Alkalis are ingested more than Acids
Accidents occur in children due to
- The substance being in the area where children can reach
- Children cannot read warning labels
- The liquid has no smell and no taste
- Stored in containers that mimic known containers (i.e. soft drink bottles, juice containers)
Over 60% of Adult ingestions are INTENTIONAL.
- Females ingest intentionally more than Males
- Acids are ingested more frequently than Alkalis
MECHANISM OF INJURY
There is a difference in the mechanism of injury of acids and alkalis.
Acid ingestion causes coagulation necrosis which means the tissue dies, but the tissue is still firm in texture. Where the coagulation forms, the extent of injury is limited. Often, acid ingestion creates burns where it touches the tissue, unless there is a large volume of acid.
Alkali ingestion causes liquefaction necrosis which means that the affected tissue is turned from a solid to a liquid. This process seems to manifest itself, penetrating the surrounding tissues.
There is a direct relationship between quantity, duration, concentration and the severity of the caustic injury (Ryan et al 2006).
The presence of stenosis is directly related to the amount and concentration of Caustic Soda.
Injury can occur at the slightest amount of residual. It does depend on how the Caustic Soda was ingested as to where the injury would most likely be.
Caustic Soda in solid form causes injury to the oral mucosa, but rarely travels further.
Caustic Soda in mild liquid form can cause oral and oesophageal injury.
Caustic Soda in concentrated form can cause significant destruction of the mouth, oesophagas and the stomach.