Corrosives/caustics

1. CORROSIVES/CAUSTICS

2. CORROSIVES
They are substances that destroys the
body tissues with which they come into
contact .
They are:
ACIDS
ALKALIS
OTHERS

3. ACIDS
 Inorganic/Mineral acids-sulphuric acid
HCl,HNO3
 Organic-oxalic acid,acetic acid,formic
acid.

4. SULPHURIC ACID
SYNONYM:oil of vitriol,oleum
PROPERTIES:
heavy,colourless,hygroscopic,non-
fuming
USES:Batteries,industries,drain/toilet
bowl cleaners,vitriolage
FATAL DOSE: 20-30 ml
TOXICOKINETICS: No absorption

5. MECHANISM OF ACTION
Acids
Release hydronium ions
Protoplasmic coagulation
Coagulation necrosis

6. SIGNS AND SYMPTOMS
 Burning sensation of GIT
 Intense thirst,
 Tongue-swollen,turns black/brown
 Teeth-chalky white
 Drooling
 vomiting
 Dribbling marks on face
 Stomach-perforation-peritonitis
 Strictures form pyloric obstruction,antral
stenosis

8. DIAGNOSIS
 Litmus test:blue-pink
 Clothing stains+ few drops of sodium
bicarbonate,produces effervescence

9. MANAGEMENT
 Decontamination of skin
 Respiratory distress
 Demulcents
 Emergency laparotomy
 Corticosteroids,antibiotics

10. THE DONT’S
 No oral feeds
 No emetics or charcoal
 No gastic lavage
 Neutralisation with alkalis is dangerous

11. HYDROCHLORIC ACID
 SYNONYMS:Muriatic acid,Spirit of salts
 PROPERTIES:colourless,fuming,turns
yellowish with air.
 USES:bleaching agent,dyeing
industry,metal refinery,preparation of
Cl,metal/drain/ceramics cleaner.
 MEDICINAL USES:achlorhydria,Hb
estimation.

12.  FATAL DOSE:30-40 ml
 TOXICOKINETICS:no absorption
 DIAGNOSIS:
1.litmus test
2.Stomach contents/vomitus
+
conc ammonia
White fumes of ammonium choride

13. MECHANISM OF ACTION
HCl
Hydronium ions
Protoplasmic coagulation(tissue
proteins),forms coagulum.
Coagulation necrosis
Tisssue damage

14. SIGNS AND SYMPTOMS
 Same as sulphuric acid poisoning
 It produces pronounced respiratory
distress
 Greyish discolouration
 Less chance of perforation
 It produces less severe effects since
HCl is naturally present in the body

15. MANAGEMENT
 Same as for sulphuric acid poisoning
 Severe pain-morphine is given
 Eye injury-retraction of eye
lids+prolonged irrigation with normal
saline or lactated ringers soln,15-30 min
 Regular follow-up for
strictures/stenosis,if present,dilatation or
esophagogastrotomy done.

17. NITRIC ACID
 SYNONYM:aqua fortis,red spirit of nitre.
 PHYSICAL PROPERTIES:colourless,yellow
fuming liquid,choking odour,dissolves all
metals except Pt & Sb.
 USES:engraving,electroplating,gold smith-
aqua regia(HNO3:HCl::3:1),fetilisers
 TOXICOKINETICS: absorption is negligible
 FATAL DOSE:20-30 ml

18. MECHANISM OF ACTION
Reacts with protein & orgaic matter to produce trinitrophenol
Liberates nitogen monoxide,xanthoprotein is formed
It produces yellow discolouration of skin,coagulation of tissue
proteins
Produces coagulation necrosis

19. SIGNS AND SYMPTOMS
 Teeth-turns yellow
 Respiratory tract-
coughing,rhinorrhea,dyspnoea
 Abdomen-distention due to gas
formation,less perforation
 Oliguria with cast and antibodies

20. DIAGNOSIS
 Litmus test
 Stomach contents+copper when heated
pungent,heavy,dark brown fumes
THERAPY
Same as for sulphuric acid poisoning
The respiratory tract should be more
secured.

21. ALKALIES
Examples include:
Ammonia-
Ammonium hydroxide-paint,oil,refrigerant
Ammonium bisulphate-fertiliser
Sodium hydroxide-drain/oven cleaner
Sodium carbonate-household cleaning
agent,detergent
pot.hydroxide-drain cleaners,hearing aid

22. PROPERTIES:
Ammonia:colourless,pungent,choking
Alkalis:white powder,colourless solns.
FATAL DOSE:
Ammonia:15-20 ml,pot.carbonate:15 gm
Sod/pot hydroxide:5 gm,
sod.carbonate:30 gm
TOXICOKINETICS: No absorption

23. Signs and symptoms
 Skin-
greyish,soapy,necrosed,cold,clammy
 Oesophagus-
dysphagia,vomiting,drooling,haematem
esis
 GI-corrosion produces red/brown
appearance,greyish pseudomembrane
forms,burning sensation,acrid,soapy
and nauseous taste.

24. Mechanism of action
Hydroxide ions saponify FAs of the cell
membrane
Protein disruption,solubilisation
Liquefaction necrosis,further penetration of
alkali

25. MANAGEMENT
 Decontamination of skin
 Respiratory system-endotracheal
intubation,cricothyrotomy,tracheostomy,oxyg
en inhalation.
 Demulcents-milk,egg white,lemon,barley
 Assess fluid and electrolyte balance
 Unbearable pain/convulsion
 Corticosteroids-to prevent stricture formation
 Antibiotics-if perforation seen.
 Proton pump inhibitors

27. REFERENCES
Fundamental of forensic medicine and
toxicology,2nd edition
R.Basu,pg no.391-399
Textbook for medicine and
toxicology,15th edition
V.V.Pillay,pg no.450-463
Forensic medicine & toxicology,2nd edn
R.N.Karmakar,pg no.63-65