The document discusses different types of asphyxiants including irritants, chemical asphyxiants, simple asphyxiants, and volatile drugs. Irritants such as smoke and tear gas injure the air passages while chemical asphyxiants like carbon monoxide and hydrogen sulfide prevent oxygen utilization. Simple asphyxiants like carbon dioxide act by excluding oxygen. Volatile drugs can act as anesthetics or toxins to organs. Specific asphyxiants are then discussed in more detail including their properties, mechanisms of action, signs and symptoms, and treatment approaches.

1. Asphyxiants
Dr Hemanth S Naik, BMCRI

2. .
Classification
Chemical Simple Volatile
Irritants Systemic
asphyxiants asphyxiants Drugs.
Dr Hemanth S Naik, BMCRI

3. IRRITANTS
 Injure the air passage
1. Smoke
2. Teargas
3. Phosgene
4. Ammonia
5. Chlorine
6. Nitrogen di oxide, etc.
Dr Hemanth S Naik, BMCRI

4. CHEMICAL ASPHYXIANTS
 Combine with hemoglobin or act on tissue
 Preventing oxygen utilization
1. Carbon monoxide
2. Hydrogen sulphide
3. Cyanide, etc.
Dr Hemanth S Naik, BMCRI

5. SIMPLE ASPHYXIANTS
 Inert gases in high concentration act
mechanically by excluding oxygen
1. Carbon di oxide
2. Methane
3. Helium, etc.
Dr Hemanth S Naik, BMCRI

6. VOLATILE DRUGS
 Act as anesthetic or toxic agents to liver,
kidney and other organs
 Hydrocarbons
 SYSTEMIC POISONS
Dr Hemanth S Naik, BMCRI

7. .
Dr Hemanth S Naik, BMCRI

8. Properties
 Colorless, tasteless, Non-irritating gas
 Produced due to incomplete combustion of
carbon
 Lighter than air
 Burns with blue flame
Dr Hemanth S Naik, BMCRI

9. Dr Hemanth S Naik, BMCRI

10. Source
Dr Hemanth S Naik, BMCRI

11. Action
Dr Hemanth S Naik, BMCRI

12. Action
 Carbon monoxide binds to hemoglobin
(reducing oxygen transportation),
 myoglobin (decreasing its oxygen storage
capacity)
 And mitochondrial cytochrome oxidase
(inhibiting cellular respiration).
Dr Hemanth S Naik, BMCRI

13. Elimination
 Major part by lung
 Half life with
1. 21% oxygen=4 – 5 hours
2. 100% oxygen=80 – 90 min
3. Hyperbaric oxygen=30 min
Dr Hemanth S Naik, BMCRI

14. Signs and symptoms
Dr Hemanth S Naik, BMCRI

15. Signs n Symptoms
 flu-like viral syndromes
central nervous system
 depression symptoms
 chronic fatigue syndrome 1. headache
 chest pain 2. dizziness
 migraine 3. confusion
 tachycardia and hypertension 4. convulsions
5. Unconsciousness
Other CVS
 muscle necrosis  myocardial ischemia,
 acute renal failure  atrial fibrillationpneumonia
 skin lesions  pulmonary edema
 visual and auditory problems,  hyperglycemia
 respiratory arrest
Dr Hemanth S Naik, BMCRI

16. Late complications
 Personality disorder
 Short term memory loss
 Parkinsonism
 Depression
Dr Hemanth S Naik, BMCRI

17. Dr Hemanth S Naik, BMCRI

18. Treatment
 First aid is to immediately remove the victim
from the exposure
 Begin CPR if needed.
 100% oxygen by a tight fitting oxygen mask.
 Hyperbaric oxygen
 Electrolyte balance
Dr Hemanth S Naik, BMCRI

19. Postmortem changes
 External
1. Cherry red color of skin
2. Cutaneous bullae
 Internal
1. Cherry red color of blood n tissues
2. Pulmonary n cerebral edema
3. Necrosis n cavitation of basal ganglia, globus
pallidus
Dr Hemanth S Naik, BMCRI

20. Carbon monoxide poisoning and haunted house ! ! !
Dr Hemanth S Naik, BMCRI

21. WAR GASES
Dr Hemanth S Naik, BMCRI

22.  .
Definition: Any chemical (gaseous, liquid, solid)
used to produce destruction or damage mostly at
the time of war
Classification
 Vesicants or Blistering Gases
 Asphyxiants or Lung irritants
 Lachrymators or Tear gas
 Nasal irritants
 Paralysants n Nerve gases
Dr Hemanth S Naik, BMCRI

23. Vesicants
 Causes irritation of skin, nose, throat and
respiratory passage
 Nausea, vomiting and abdominal pain
1. Mustard gas
2. Sulphur
3. Phosgene
4. Volatile liquids
Dr Hemanth S Naik, BMCRI

24. Mustard gas
 Most effective gas of the First World War
 Introduced by Germany in July 1917
One nurse, Vera Brittain, wrote: "I wish those people
who talk about going on with this war whatever it
costs could see the soldiers suffering from mustard
gas poisoning. Great mustard-coloured blisters,
blind eyes, all sticky and stuck together, always
fighting for breath, with voices a mere whisper,
saying that their throats are closing and they know
they will choke."
Dr Hemanth S Naik, BMCRI

25. .
.
Dr Hemanth S Naik, BMCRI

26. .
Dr Hemanth S Naik, BMCRI

27. Tear Gas
 During the first World War, the French were
the first to employ gas, using 26 mm grenades
filled with tear gas (ethyl bromoacetate) in
August, 1914
 Mainly Chloracetophenone (C.A.P),
Ethyliodoacetate (K.S.K), Bromobenzylcynaide
(B.B.C) are used
Dr Hemanth S Naik, BMCRI

28. .
Dr Hemanth S Naik, BMCRI

29. Nasal irritants
 Mainly used to control riots
 Ortho-chlorobenzylidene malanonitrate (CS)
used by Law Enforcement Agencies and Military
for self protection
Dr Hemanth S Naik, BMCRI

30. Nerve Gases
 Esters of Phosphoric acid n are identical in
their biological activity to organophosphates
 Colorless and odorless volatile liquids
 Inhibit acetylcholine esterase
1. Tabun (GA)
2. Sarin (GB)
3. Soman (GD)
Dr Hemanth S Naik, BMCRI

31. Sabin
Dr Hemanth S Naik, BMCRI

32. Methyl isocynate (MIC)
 Stable liquid below 27c, gaseous at 31c
 Highly volatile n inflammable
 Used in manufacture of pesticides, adhesives n
plastic
 Sings n symptoms include irritation of skin,
mucous membrane and systemic effects
Dr Hemanth S Naik, BMCRI

33. .
Dr Hemanth S Naik, BMCRI

34. Bhopal Gas Tragedy
 The Bhopal disaster was an industrial disaster
that occurred in the city of Bhopal, Madhya
Pradesh, India, resulting in the immediate deaths
of more than 3,000 people
 The incident took place in the early hours of the
morning of December 3, 1984
 A Union Carbide subsidiary pesticide plant
released 40 tones of methyl isocyanate (MIC) gas
Dr Hemanth S Naik, BMCRI

35. Dr Hemanth S Naik, BMCRI

36. .
Dr Hemanth S Naik, BMCRI

37. Dr Hemanth S Naik, BMCRI

38. Carbon dioxide
Dr Hemanth S Naik, BMCRI

39. . Heavy colorless gas with a faintly sweet odour

 Act as simple asphyxiant by preventing the
tissue from obtaining oxygen
 Symptoms include labored breathing and mental
confusion (> 5% concentration in air)
 Dyspnoea, ringing in ears, loss of muscle power,
unconsciousness, coma and death (60-80%
concentration)
 Treatment: Oxygen, artificial respiration and
symptomatic
Dr Hemanth S Naik, BMCRI

40. Dr Hemanth S Naik, BMCRI

41. Dr Hemanth S Naik, BMCRI

42. Hydrocyanic Acid (Prussic Acid)
Dr Hemanth S Naik, BMCRI

43. Properties
 vegetable acid (distributed in many fruits n
leaves) in the form of harmless glucoside
amygdalin
 colorless gas or pale blue, highly volatile liquid
 has a faint, bitter almond-like odor
Dr Hemanth S Naik, BMCRI

44. Other names
1. Hydrocyanic acid
2. Prussic acid
3. Formonitrile
4. Formic anammonide
5. Carbon hydride nitride
6. Cyanane
7. Cyclon
Dr Hemanth S Naik, BMCRI

45. Structure
Dr Hemanth S Naik, BMCRI

46. Source
 Cherries, apricots, apples, bitter almonds
 Some millipedes , burnet moths release
hydrogen cyanide as a defense mechanism
 contained in the exhaust of vehicles, in tobacco
and wood smoke
 100 g of crushed apple seeds can yield 219 mg
of Amygdalin which can generate ~10 mg of
HCN
Dr Hemanth S Naik, BMCRI

47. Dr Hemanth S Naik, BMCRI

48. Dr Hemanth S Naik, BMCRI

49. Application
 Tempering steel
 Dyeing
 Explosives
 Engraving
 Acrylic resin plastic
Dr Hemanth S Naik, BMCRI

50. Action
 Inhibits the action of cytochrom oxidase,
carbonic anhydrase (Oxygen utilization
hindered)
 Interfere with intracellular oxidative process in
the tissues
Histotoxic anoxia
Dr Hemanth S Naik, BMCRI

51. Absorption n Excretion
Cyanide Stomach
(Inhaled, Ingested) (HCL, gastric juice)
Hydrocyanic acid
and chlorine
Dr Hemanth S Naik, BMCRI

52. Signs n symptoms
 Burning taste, feeling of constriction in the
throat .
 Excessive salivation and blood stained froth
 Headache, vertigo and giddiness
 Hurried breath n increased blood pressure with
decreased heart rate
 Smell of bitter almond
Dr Hemanth S Naik, BMCRI

53. Dr Hemanth S Naik, BMCRI

54. Signs n symptoms
 Convulsions n unconsciousness
 Opisthotonus, trismus
 Skin is covered with sweat and is brick red in
color
 Eyes are glassy and prominent, pupils dilated
and non reactive to light
Dr Hemanth S Naik, BMCRI

55. Fatal dose
 HCN: 50 – 60 mg
 KCN: 200 – 300 mg
 NaCN: 200 – 300 mg
Fatal period
 HCN: 2 – 3 mg
Dr Hemanth S Naik, BMCRI

56. Treatment
Principle
Methemoglobin
Haemoglobin
By giving nitrates
Thiocyanate Cyanmethemoglobin
Excreted in urine Non toxic
Dr Hemanth S Naik, BMCRI

57. Dr Hemanth S Naik, BMCRI

58. Treatment
 Break 0.2 ml ampoule of AMYL NITRITE in a
hand kerchief and hold over the patients nose
for 15 – 30 sec every min
 SODIM NITRITE infusion
 SODIUM THIOSULPHATE infusion
 VIT B12 4 mg iv infusion
 EDTA chelating agent
Dr Hemanth S Naik, BMCRI

59. Postmortem changes
 Postmortem staining cherry red in color
 Bitter almond odor
 Edema of lungs
 Stomach mucosa red and congested
Dr Hemanth S Naik, BMCRI

60. Dr Hemanth S Naik, BMCRI

61. Hydrogen Sulphide
Dr Hemanth S Naik, BMCRI

62. Properties
 Colorless gas.
 Odor similar to rotten eggs
 Produced in nature primarily through the
decomposition of organic matter by bacteria.
 Sewer gas contains hydrogen sulphide
Dr Hemanth S Naik, BMCRI

63. Sewer Gas (carbon dioxide, methane, hydrogen sulphide)
 5
Dr Hemanth S Naik, BMCRI

64. Action
 Inhibition of cytochrome oxidase
 Binds to hemoglobin in red blood cells
interfering with oxygen transport.
Exposure to hydrogen sulfide occurs primarily by
inhalation but can also occur by ingestion (contaminated
food) and skin (water and air).
Dr Hemanth S Naik, BMCRI

65. .
 .
Dr Hemanth S Naik, BMCRI

66. Signs n symptoms
 Beginning of Eye Irritation
 Slight conjunctivitis and respiratory tract
irritation
 Loss of consciousness
 Cessation of respiration, and death
Dr Hemanth S Naik, BMCRI

67. Treatment
 Move the patient to fresh air immediately
 100% oxygen
 Amyl nitrite inhalation
 Sodium nitrite infusion
Dr Hemanth S Naik, BMCRI

68. Postmortem changes
 Rotten egg odour
 General signs of asphyxia
 Greenish purple discoloration of blood and
viscera
Dr Hemanth S Naik, BMCRI

69. Dr Hemanth S Naik, BMCRI