1. Corrosive Poisons

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

3. Classification Acids Alkalis Mineral acids Organic acids
Vegetable acids

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

5. Vegetable acids
Hydrocyanic acid

6. Classification Alkalis Ammonia Calcium hydroxide Caustic potash & Soda
Ammonium hydroxide

7. 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

8. Mineral acids: produce coagulation necrosis
Alkalis: produce liquefaction necrosis

9. Signs and Symptoms Onset : immediate Symptoms:
Burning sensations (mouth, throat, esophagus, stomach)
Intense thirst
Dysphagia, retching
Hematemesis

10. 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

11. 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

12. 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

13. TREATMENT Stomach tube and emetics are contraindicated
However soft stomach tube (levine tubes) can be passed within one hour to prevent serious caustic burns.

14. 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

15. 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

16. 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

17. POSTMORTEM APPEARANCE
Depends on:
Quantity
Strength of acid
Time the patient survives after intake of acid

18. 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.

19. Gastric perforation: esp with sulphuric acid
Irritation of respiratory tract: (volatile poisons like nitric acid, HCL)

20. 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.

21. Vitriolage:
Throwing of a corrosive on face out of jealousy or rage.

22. 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.

23. 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

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

25. 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

26. 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

27. Eyes: Washed with large amount of water and irrigated by 1 % solution of sodium bicarbonate.
Eye drops containing steroids and antibiotics are helpful

28. 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