Hydrogen Peroxide - Corrosive(Caustic) Poisons

Hydrogen Peroxide

Synonyms

Albone; Carbamide peroxide; Hydrogen dioxide; Urea peroxide.

Physical Appearance

Commercial topical solution of hydrogen peroxide is a clear, colourless liquid with a faint ozone-like odour and bitter taste. It deteriorates on standing, repeated agitation, or exposure to light.

Uses

o     Disinfectant

o     Radiology: A mixture of hydrogen peroxide with barium can help identify the exact site of gastrointestinal haemorrhage under fluoroscopy, since bubbles are formed when blood is brought in contact with hydrogen peroxide.

o     Treatment of inspissated meconium, constipation, and faecal impaction.

o     Mouth wash/gargle.

o     Hair and teeth bleaching.

o     Vaginal douche.

Industry:

o     Synthesis of various compounds, bleaching agent for paper and textiles, and in rocket fuel.

o     The 3% solution is used in plastics manufacturing; in bleaching hair, feathers, silk, and textile fabrics; in renovating paintings and engravings; as an oxidiser in the manufacture of dyes; in disinfecting water and hides; in artificially aging wines, liquors, etc.

o     Hydrogen peroxide is also used as a source of organic and inorganic peroxides, in foam rubber, in glycerol manufacturing, in electroplating, as a laboratory reagent, as an oxidising and bleaching agent in foods, as a seed disinfectant, and as a substitute for chlorine in water and wastewater treatment.

o  “Food grade” hydrogen peroxide solutions have recently been marketed in health-food stores in the West, to be diluted and used in “hyper-oxygenation therapy” to treat conditions ranging from arthritis to cancer to AIDS. This has resulted in an increased number of accidental exposures to these products.

o  Hydrogen peroxide is effective in loosening cerumen (ear wax) that occludes the auditory canal, and can clear blocked ventilation tubes used in the treatment of conductive hearing loss caused by otitis media with effusion.

Usual Fatal Dose

Not clear. Fatalities are mostly associated with industrial grade solutions.

Mode of Action

Hydrogen peroxide decomposes to water and oxygen. When used in closed spaces or under pressure, liberated oxygen cannot escape. Systemic oxygen embolisation and surgical emphysema can occur.

Clinical Features

Household hydrogen peroxide (3 to 9%) is mildly irri-tating to mucus membranes. In general, ingestion, ocular, or dermal exposure to small amounts of dilute hydrogen peroxide will cause no serious problems.

a. 1 ml of a 3% solution liberates 10 ml of oxygen. Therefore ingestion of a large amount of hydrogen peroxide solution even if it is very dilute can result in gastric distension. Irritation of gastrointestinal tract often results in vomiting.

b. Oral contact with dilute (3%) solutions may induce oral gingival ulceration or enhance prior injuries of the mucous membranes of the mouth. Hypertrophy of the papillae of the tongue may occur from chronic use of hydrogen peroxide mouthwash.

Ingestion of industrial strength hydrogen peroxide (35 to 90%) can cause severe burns of GI mucosa with a tendency to gastric perforation (due to oxygen liberation). Oxygen emboli can also be produced which can be life-threatening. Foam formation can result in respiratory tract obstruction and respiratory failure. Metabolic acidosis and convulsions have also been reported.

Dermal exposure to concentrated solutions has resulted in burns and gangrene. If contact with the skin is relatively short no damage will occur beyond a whitening or bleaching accompanied by a tingling sensation. The skin returns to normal within 2 to 3 hours if it has been washed promptly after contact. However, hair may remain permanently bleached.

Diagnosis

·      Clinical: Foaming at mouth or nose, gastric distension,cerebral oedema.

·      Radiological:

o     Gas in mesenteric, gastric, splenic, or portal venous systems.

o     Gas in inferior vena cava or right ventricle.

o     Gastric or duodenal distension.

Treatment

·      Aggressive airway management comprising endotracheal intubation, oxygen administration and mechanical ventila-tion.

·      Following ingestion, administer water immediately to dilute the peroxide. Spontaneous vomiting is common.

·      After endotracheal intubation, cautious gastric lavage may be attempted with iced saline.

·      Supportive measures with particular reference to control of metabolic acidosis and convulsions.

·      Laparotomy may be required if there is evidence of air in the GI tract.

·      Hyperbaric oxygen therapy may help alleviate life threat-ening gas embolisation.

Autopsy Features

1. Gross –

o     Foam at the mouth or nose.

o     Frothy blood in venous systems.

o     “Frosty coating” of GI tract.

o     Crepitus of liver.

o     Diffuse cerebral oedema with cerebellar and uncal tonsillar notching.

o     Visceral congestion.

o     Petechiae of thymus, pericardium, and other viscera.

2. Microscopic –

o     Evidence of gastritis, duodenitis, or colitis.

o     Clear vacuoles in the submucosa of GI tract, GI veins, lymphatics, and mesenteric lymph nodes.

o     Organ vacuolisation (gas emboli).

o     Chemical analysis of viscera is a futile exercise.

Forensic Issues

Most cases of poisoning result from therapeutic misadventure.

A few may be related to suicidal intent.