Corrosive is any substance that in contact with living tissue will cause destruction by chemical action. It includes substances at both extremes of pH, i.e. acids and alkalies.
Acetic acid, Carbolic acid, Hydrochloric acid, Formic acid, Nitric acid, Oxalic acid, Phosphoric acid, Sulphuric Acid, Monochloroacetic acid.
Common Household Products
Toilet bowl cleaners, drain cleaners, metal cleaners and antirust compounds, gun bluing agents, automobile battery fluid, smoldering fluxes, Engraver’s acid (industries).
NaOH, KOH, Ammonium Hydroxide, Calcium Carbonate, Calcium Hydroxide, Sodium Hypochlorite, Calcium Oxide.
Common Household Products
Drain cleaner, household ammonia (hair products, jewelry cleaner, household cleaner), automatic dishwasher detergent, Clinitest tablets, oven cleaners, swimming pool sanitizers, household bleach products, hair relaxer products, cement (CaO), paint remover, washing powder, miniature/button batteries, paint remover, washing powder.
Classification of Corrosives
Corrosion means dissolution or gradual wearing away by chemical action. The corrosive poisons are classified as follows:
|Mineral Acids||a. Sulphuric acid
b. Nitric acid
c. Hydrochloric acid
|Organic Acids||a. Oxalic acid
b. Carbolic acid
c. Acetic acid
d. Salicylic acid
|Vegetable Acids||a. Hydrocyanic acid|
|Alkalis||a. Caustic potash and soda
b. Ammonium hydroxide
Pathophysiology of Corrosives Poisoning
Acids cause coagulative necrosis (except HFl that causes liquefactive necrosis by combining with Ca and Mg in the tissues).
Alkalis cause liquefactive necrosis.
Three pathophysiologic phases characterize both acid & alkali ingestion:
- Acute Inflammatory Phase
- lasts 4 to 7 days
- vascular thrombosis & cellular necrosis occus
- destruction of columnar epithelium, sub mucosa & muscularis takes place
- injury peaks in first 24-48 hrs
- necrotic mucosa sloughs by 3rd or 4th day and ulcer forms
- Latent Granulation Phase
- begins at middle of 1st week
- fibroplasia develops
- fresh granulation tissue fills area of sloughed mucosa
- collagen replaces granulation tissue by end of 1st week
- perforation is most likely in this phase
- lasts 2 weeks after injury
- Chronic Cicatrization Phase
- begins 2-4weeks after injury
- formation of scar tissue around sub mucosa & muscularis occurs
- primary goal is to prevent stricture formation
Determinants of Injury
Injury depends on:
- type of substance ingested
- volume ingested
- contact time
- volume of liquid & material in stomach
- concentration & pH of substance
Management of Corrosives Poisoning
-Irrigate for at least 20-30 mins & until eye fluid pH is 7
-Topical ophthalmic anesthetic agents (proparacaine, tetracaine) are helpful
-Do NOT use neutralizing solutions
-Complete eye examination with slit lamp must be done including evaluation for corneal burns & foreign bodies. Visual acuity must be assessed and fluorescein staining (for corneal & conjunctival abrasions/ulcerations) must be performed.
Depending upon severity cycloplegic drops, antibiotic drops and artificial tears should be used. Steroid eye drops must only be used in consultation with ophthalmologist.
Flood with water for 15 mins. No chemical antidote is to be used.
Skin contact is treated as thermal burns with debridement, topical antibiotic ointment, non adherent sterile gauze and wrapping. Deep 2nd degree burns may benefit from silver sulphadiazine.
For hydrofluoric Acid burns:
- soak in benzalkonium chloride solution or
- apply 2.5% Calcium gluconate gel or
- inject 0.5ml of 5% Calcium gluconate/cm2 under burned area
Remove from the environment and administer humid supplemental Oxygen. Intubation and respiratory support may be needed.
Observe for airway obstruction & noncardiogenic pulmonary edema. Radiographs and arterial blood gases may be required.
In ingestion cases dilution and supportive care is done.
Use milk or water (limited to 8 oz for adults & 4 oz for children due to danger of heat generated by exothermic reaction.
Removal of stomach contents by using nasogastric tube in large volume ingestion may be used.
Flexible endoscopy may be performed promptly to evaluate burns.
Substances NOT to be used include emetics, neutralizing agents, bicarbonate and activated charcoal. Gastric lavage is NOT to be done.
- Corticosteroids for preventing stricture formation, however use is controversial
- Antibiotics for documented infection
- Oral liquids not to be started until endoscopy shows extent of injury
-1st degree burns-when stable
-2nd degree burns-not for 2-3 days
-3rd degree burns-require surgically placed jejunostomy tube
Indications for Surgery
- major bleeding