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