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Classification of Corrosive poisons and Sulphuric acid poisoning

Corrosives - The definition:

A corrosive is a substance that fixes, destroys and erodes the surface with which it comes into contact.

The word 'corrosion' is derived from the Latin verb ’corrodere’, which means 'to gnaw', indicating how these substances seem to 'gnaw' their way through the flesh.

Classification of Corrosive poisons:

1.Mineral acids 2. Organic acids -Sulphuric acid -Oxalic acid -Nitric acid -Carbolic acid -Hydrochloric acid -Acetic acid -Salicylic acid

3. Vegetable acid 4. Alkalis -Hydrocyanic acid - Caustic potash and soda - Ammonium hydroxide

Mechanism of action of corrosives:

Any part of the body + corrosive substance

Extraction of water

Liberation of heat

Coagulation and precipitation of cellular proteins

Conversion of hemoglobin to hematin

Corrosion and destruction of tissues

Sulphuric acid

‘Oil of Vitriol’; ‘Battery acid’; ‘Oleum’

Physical appearance:

Heavy, odorless, colorless, non-fuming, oily liquid.

Has a tendency to carbonize organic substances.

Hygroscopic; has great affinity for water and evolves tremendous heat when mixed with it.

Uses: Industrial chemical

Storage batteries and accumulators

Pipe and drain cleaners

Laboratory

Fatal dose: 10 to 15 ml

Fatal period: 12 to 24 hours

Clinical features:

Corrosion of mucous membranes of mouth, throat,

esophagus.

Epigastric pain spreads all over the abdomen and

thorax.

Pharyngeal pain- the most common presenting

symptom.

Teeth- chalky-white.

Tongue- swollen, sodden and black.

Abdomen- distended, very tender.

Eyes are sunken and pupils dilated.

Dysarthria DysphagiaRetching VomitingHematemesisDehydrationConstipationTenesmusStarvation Thirst

Perforation of stomach

Chemical peritonitis

Stricture of esophagus and pylorus

Dysphagia, infection

GIT- Signs and symptoms:Severe burns in mouth, esophagus and stomach.

SHOCK AND DEATH

Respiratory signs:Inflammatory edema of glottis or larynx

Dyspnoea

Suffocation Death

Complications and The Cause of death:1.Circulatory collapse.

2.Spasm or edema of glottis.

3.Collapse due to perforation of stomach.

4.Toxaemia.

5.Delayed death due to— hypostatic pneumonia secondary infection renal failure starvation due to stricture of the esophagus.

Treatment:

Gastric lavage, activated charcoal and emetics- contraindicated.

Acid immediately diluted and neutralized in situ by- - One-fourth litre of water or milk - Milk of magnesia or lime water - Aluminium hydroxide gel; within 30 minutes of ingestion.

Alkaline carbonates and bicarbonates- contraindicated.

Prednisolone- 60mg/day; to prevent esophageal stricture and shock.

A 3-4 cm mercury-filled bougie is passed daily if stricture develops.

Correct circulatory shock.

Tracheostomy if there is oedema of the glottis.

Concomitant prophylactic broad-spectrum antibiotic use is recommended.

No oral feed until endoscopy confirms the extent of

injury.

Eye burns require copious irrigation with sodium

bicarbonate with the eyelids retracted for 10-15

minutes. A suspended i.v. bag that administers low

pressure irrigation is ideal.

Laparotomy is required for patients with gastric

perforation and peritonitis.

Autopsy findings:

External: Evidence of acid corrosion and chemical burns with brownish-black parchment like and corroded spots are seen over the chin, cheek, neck and chest resulting from trickling of the acid.

Excoriation of lips.

Corrosion of mucosa of mouth and tongue.

Chalky-white teeth.

Internal:Limited to the upper digestive tract and respiratory system. Mucous membrane of esophagus inflamed, swollen by edema and severe interstitial hemorrhage present, even when corrosion is absent.

Greater part of the stomach converted into soft, boggy, black mass that readily disintegrates on touching. Blackened with peppery feel.

The Small intestine shows evidence of irritation.

Severe inflammation of the larynx and trachea.

Diagnosis:

Litmus test:

The pH of the saliva tested to determine whether the chemical ingested is an alkali or an acid.

Fresh stains in clothing may be tested by adding a few drops of sodium bicarbonate.

Production of an effervescence is indicative of an acid stain.

Radiology: In view of the high rate of perfusion, water soluble contrast agents are used for evaluation.

Diffuse mottling of lung fields on X-ray when there is inhalation of acid vapor.

Chest and abdominal X-rays and routine laboratory testing should be obtained to evaluate for Aspiration, Perforation and Organ dysfunction.

Endoscopy: Used to document the site of injury and its severity.

Better performed 12-14 hours after ingestion.

The squamous epithelium of the esophagus is relatively resistant to acid burns, while the columnar epithelium of the stomach is very susceptible.

Hence perforation of the stomach is more frequent than that of the esophagus.

Medico-Legal aspects:

Accidental poisoning results due to mistaking it for glycerin or castor oil.

In suicide.

Rarely used in homicide.

Taken internally or injected into the vagina as an abortifacient.

Vitriolage.

THE ACID-BATH MURDERER:Have a body to get rid off? Talk to Haigh.

On 18th February 1949,John George Haigh, self-professed owner of a factory, induced an early widow to accompany him to his warehouse where he shot her and then dumped her bodyafter removing some valuables, in a steel tank filled withsulphuric acid.

•28 pounds of human body fat•Three faceted gallstones•Part of a left foot, not quite eroded•Eighteen fragments of human bone•Intact upper and lower dentures•The handle of a red plastic bag•A lipstick container

The remains were discovered by the police on March 1st. By then, the body had been converted into a sludgy, greasy material. Careful retrieval by the forensic pathologist Prof. Keith Simpson yielded-

“BUT IF THERE ARE NO BODIES, HOW CAN I BE CHARGED WITH MURDER?”

Thank you!