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 DEATH IMMEDIATE Shock Suffocation: edema/spasm of glottis Gastric perforation DELAYED (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