CORROSIVE POISONS6666 toxicity.pptx Toxicology

Toxicology

1. CORROSIVE POISONS By Hassan Mohammed Al- Mahbashi Professor of Pharmacology & Toxicology Department of Forensic Medicine & Clinical Toxicology

2. Definition Any substance that in contact with living tissue will cause destruction by it's chemical action. Its almost exclusively locally acting and has very few systemic action with the exception of generalized shock .  

3. Classification

4. Inorganic Acids Common sources: Industry Laboratories Domestic use Agriculture Explosives manufacturing.

5. Inorganic Acids Sulfuric acid H2SO4 : colorless, odorless, hygroscopic liquid. i.e. it has a great affinity to absorb water, causing charring of any organic mater when it comes in contact with it.

6. Uses Used in Battery acid Toilet bowl cleaners. Wine fermentation. Fatal dose -: 5 ml of the concentrated commercial acid.

7. Inorganic Acids Hydrochloric acid HCl : colorless or yellow volatile liquid. : used in swimming pool cleaners. Toilet bowl cleaners ( Flash or Harbic ). Dye manufacturing. Fatal dose -: 15 ml of the concentrated commercial acid, HCl is normally present in stomach in a concentration of 0.3%, so quantitative estimation can be done.

8. Inorganic Acids Nitric acid HNO 3 : colorless highly volatile (fuming), more liable to produce respiratory symptoms and edema glottis . used in: In electroplating. Fertilizer manufacturing. Fatal dose : 4 ml of the concentrated commercial acid.

9. Medico-legal aspects Accidental drinking of the strong acids. Homicidal : in cases of vengeance, by throwing it on the body of the victim ( Vitriolage ) . Suicidal : never, because of its burning taste.

10. Clinical features: Corrosion of the skin and mucus membranes.

11. Clinical features: Severe burning pain from the mouth down the stomach. Vomiting.( black in color –shreds of stomach mucosa +acidic haematine ) Clothes may show streaks of charring. Pulmonary complications e.g. pneumonia, edema glottis. Corneal corrosions.

12. Clinical features : If skin exposed Black eschars – H2SO4 Red eschars –HCL Yellow eschars –HNO3

13. Causes of death: Shock due to the burning pain.( neurogenic ) Peritonitis due to perforation of the stomach. Pulmonary complications. Late complication : strictures of esophagus and stomach

14. 2. Alkalis: Na and potassium hydroxide NaOH (caustic soda), KOH(caustic potash).   Usually milky or white solids. Common sources: Industry, soap manufacturers and laboratories.  Fatal dose : 5 grams.

15. 2. Alkalis: used in:  Oven cleaners  Detergents.  Paint removers  Washing powders

16. Mode of poisoning: Usually accidental: in cases of children as they resemble milk and during their industrial use.

17. Clinical picture: Severe burning pain from the mouth down the stomach, abdomen and chest. Vomiting : the vomit is soapy or bloody and alkaline. Diarrhea : soapy diarrhea or bloody with mucus. Respiratory edema : cough, cyanosis, dyspnea . Shock : leads to death.

18. Ammonium hydroxide It is highly volatile corrosive, has penetrating odor, it produces symptoms as other corrosives beside respiratory manifestations leading to respiratory distress and sense of suffocation and lacrimation . Fatal dose : 8 ml by oral route.

19. Cause of death: Death occurs from shock , asphyxia and pulmonary edema.

20. Clorox Clorox is a bleaching agent, contains Na hypochlorite in a concentration up to 10%, it has a corrosive action partly due to the formation of hypochlorous acid and liberation of free chlorine When hypochlorite reacts with gastric acid. The chlorine may in turn be inhaled and causes respiratory symptoms.

21. Mode of poisoning: Accidental -in children mainly under 5 years of age, small dose In suicidal attempts particularly by girls – large dose . It may be used as well by females for whitening of the teeth.

22. Treatment: 1-In small ingested doses only anti-acid or milk should be given with immediate water gargling. 2. If big doses are ingested, sodium thiosulfate should be given to reduce the remaining hypochlorite in the stomach. 3. Corticosteriods are helpful to decrease laryngeal edema.

23. Flash or Harbic : Contains concentrated HCl , used as a toilet and bowl cleaner. It's effect is that of HCl .

24. Shampoos: Have very low toxicity apart from slight irritation of mucosal surfaces but those containing anti-dandruff may have more effects particularly those containing selenium.

25. Soaps Most of used solid soaps are non poisonous, used sometimes in cases where ipecac is not available for induction of emesis .

26. Complications of corrosive toxicity : Sulfuric acid may be thrown on the face of persons for vengeance causing: Burns of skin And/or eye destruction and loss of vision ( permanent infirmity ). Scars of eye or mouth which remain open and exposed to inflammations or dribbling of saliva. Scar in neck, twisted to one or other side. Scar in limbs causing limitation of joint movements. Keloid may have malignancy transformation.

27. Other acids and alkalis complications: I. Acute complications: 1. Upper air way obstruction. 2. G.I.T hemorrhage. 3. Esophageal and gastric perforation . 4. Sepsis.

28. II. Chronic complications: 1. Esophageal obstruction 2. Pyloric stenosis . 3. Squamous cell carcinoma of esophagus 4. Vocal cord paralysis

29. GENERAL MANAGEMENT OF CORROSIVE POISONING I. Dilution: Minimize damage to oral, esophageal and gastric tissues. Water milk is the best local antidote, chemically (as a buffer) and physically (has a dilution and demulcent effect). .

30. Contraindications: 1. Neutralizing agents 2. Gastric lavage : may cause perforation 3. Emesis 4. Cathartics 5. Charcoal

31. Treatment of shock and pain: 5 – 10 mg morphine I.V or strong analgesic must be given.

32. III. Treatment of dehydration: I.V drip using 5% dextrose in saline , keeping the electrolyte and acid base balance, hypervolemia has to be avoided which leads to pulmonary edema and heart failure.

33. VIII. Eye and skin decontamination : through wash with large quantities of water.

34. Diagnostic procedure: Esophagoscopy to determine the extent of injury.

35. Steroids: Dexamethasone Hydrocortisone may be given to relief laryngeal edema and to delay esophageal Stenosis .

36. Antibiotics for pneumonia:

37. VI. Nutrition by I.V fluids or by soft Ryle's tube (after the acute stage).

38. VII. Surgical intervention: As follows: - Tracheostomy for suffocation by edema of larynx or glottis - Partial gastroctomy for gastric perforation. - Esophageal dilatation or transplant . stenosis .

39. Treatment of skin burns i . Wash the parts with plenty of water and soap. ii. Apply thick paste of MgO or carbonate. iii. Cover raw surface with antibiotic ointment . iv. For eye burns, the conjunctiva and corneal surfaces are anesthetized with topical anesthetic drops (e.g. proparacaine ) and irrigated with water for 15 min holding the eyelids open. Repeat irrigation using 0.9% saline, till pH is near 7.0. Eye drops containing antibiotics and steroids are helpful.