Corrosive Poisons

Definition

A corrosive poison fixes,destroys and erodes the surface with which it comes in contact.

Classification Acids Alkalis Mineral acids Organic acids Vegetable acids

Mineral acids Sulphuric acid Nitric acid Hydrochloric acid Organic acids Oxalic acid Carbolic acid Acetic acid Salicylic acid

Vegetable acids Hydrocyanic acid

Classification Alkalis Ammonia

Calcium hydroxide Caustic potash & Soda Ammonium hydroxide

Mode of action(Mineral acids & alkalis)

Extraction of water from tissues Coagulation of surface proteins Conversion of hemoglobin into hematin Mainly acts on GIT,to some extent on

respiratory tract. No remote systemic action with

exception of shock In dilute solutions they act as irritants

Mineral acids: produce coagulation necrosis

Alkalis: produce liquefaction necrosis

Signs and Symptoms

Onset : immediate Symptoms:

Burning sensations (mouth, throat, esophagus, stomach)

Intense thirst Dysphagia, retching Hematemesis

Vomitus is either acidic or alkaline depending on substance swallowed.

Mouth & lips are corroded Tongue;swollen or shriveled Teeth: chalky white - Sulphuric acid poisoning

yellowish - Nitric acid poisoning Constipation & scanty urine with corrosive acids Bloody diarrhea with alkalis

Ammonia vapours: Congestion, watering of eyes, cough, choking.

Collapse occurs because of suffocation Dyspnea: edema of glottis Cardiovascular shock:(Cold clammy skin, pale face, dilated pupils,

rapid pulse & sighing respiration) Consciousness is usually retained till the

end

CAUSE OF DEATHIMMEDIATE Shock Suffocation: edema/spasm of glottis Gastric perforationDELAYED (quantity of poison small) Hypostatic pneumonia Esophagial stricture :(emaciation and malnutrition) Secondary infections

TREATMENT Stomach tube and emetics are

contraindicated

However soft stomach tube (levine tubes)

can be passed within one hour to prevent

serious caustic burns.

ACID POISON: Alkaline carbonates & bicarbonates - contraindicated

Weak alkalis e.g. calcium and magnesium hydroxide along with plenty of water or neutralizing agents like milk and egg albumin is given

ALKALI POISON: Neutralize poison by giving acids like

acetic acid,citric acid mixed with large quantity of water

Morphine: to relieve pain Ice: to relieve thirst IV fluids: to compensate fluid loss Steroids: Shock

To prevent esophageal strictures Keep the airway patent

Tracheostomy: Acute edema of glottis Poisoning by ammonia vapors give

oxygen

Keep the patient NPO Nutrient substances are given by IV route

for about a week. Try liquids,soft food and finally a regular

diet. Antibiotics to prevent infection

POSTMORTEM APPEARANCE

Depends on:

Quantity

Strength of acid

Time the patient survives after intake of acid

Corrosion of mucus membranes of lips, mouth, throat & skin over the chin, angles of mouth & hands.

Necrotic areas - brown or black and leathery. More marked in cases of sulphuric acid

poisoning. Tissues - stained yellow in nitric acid

poisoning.

Gastric perforation: esp with sulphuric

acid

Irritation of respiratory tract: (volatile

poisons like nitric acid, HCL)

MEDICO LEGAL ASPECTS Attempted Suicides: Not seen now a days due to use of less

painful substances like barbiturates, narcotics & organo-phosphorous compounds.

For Homicides: Rarely; because of taste, immediate local

action & physical changes it produces in food.

Vitriolage: Throwing of a corrosive on face out of

jealousy or rage.

VITRIOLAGE Throwing of any corrosive on a person

with malicious intent. These fluids are usually thrown on face for

destroying vision or causing facial disfigurement.

Results in Grievous Hurt.

Sulphuric acid - Commonly used. Causes chemical burns Burns are painless, penetrating Acid devitalizes tissues, predisposes to

infection. Repair is slow Scar causes contractures. Death may result from shock, toxemia if

extensive areas are involved

Other acids/ chemicals used Nitric acid Carbolic acid Caustic soda Caustic potash Iodine Marking nut juice

SIGNS AND SYMPTOMS Sulphuric acid: Brown or black

discoloration and staining of skin and clothing.

Nitric acid: yellow stain Trickle marks Red line of demarcation

TREATMENT Wash the corrosive acid with large amount

of water and soap or dilute solution of sodium or potassium bicarbonate.

Thick paste of magnesium oxide is applied Raw surface - covered with antibiotic

ointment

Eyes: Washed with large amount of water

and irrigated by 1 % solution of sodium

bicarbonate.

Eye drops containing steroids and

antibiotics are helpful

CHEMICAL BURNS

EFFECT Alkali Acid

Injury Severe Less severe

Necrosis Liquefaction Coagulation

Burns Deep 2nd degree

Edema Marked Mild

Eschar Soft, edematous, translucent

Hard

Charring Not seen Seen