ASPHYXIANTS.pptx

Forensic Toxicology- Asphyxiants is a substance that can cause unconsciousness or death by suffocation.

1. ASPHYXIANTS Dr Anu Mariam Varghese 3 rd MD Scholar Dept of Agadatantra GAVC, TVM

2. CLASSIFICATION POISON Corrosives Irritants Systemic Miscellaneous a. Cerebral b. Spinal c. Peripheral d. Cardiovascular e. Asphyxiants

3. An asphyxiant is a substance that can cause unconsciousness or death by suffocation. Substances that cause asphyxial death – asphyxiants

4. CLASSIFICATION Henderson and Haggard 1. Irritants 2. Chemical asphyxiants 3. Simple asphyxiants 4. Volatile drugs 5. Systemic poisons

5. 1. Irritants Gases injure air passages/lungs/both Produce inflammatory change Smoke, tear gas, ammonia, formaldehyde, chlorine 2. Chemical asphyxiants Combines with Hb --> prevents oxygen from reaching tissues CO, Hydrogen sulphide , cyanide 3. Simple asphyxiants Inert gases When breathed in high con. Acts mechanically by excluding O2 CO2, methane, nitrous oxide, N2

6. 4. Volatile drugs No irritant effect on air passages. Acts after absorption into blood. Toxic to liver, kidney and nervous system Aliphatic, aromatic, halogenated hydrocarbons 5. Systemic poisons Insecticides

7. CARBON MONOXIDE - CO CARBON DIOXIDE - CO 2 HYDROGEN SULPHIDE - H 2 S

8. 1. CARBON MONOXIDE

9. FEATURES Colorless, tasteless, non irritative gas produces due to incomplete combustion of carbon. Insoluble in water. Burns with blue flame Lighter than air Mixture of CO with 2 ½ times its volume of air – highly explosive in presence of flame

10. source

11. Common source - coal gas, smoke from fires, fumes from defective heating appliances. Industry - 20% Smoking

12. ACTION

13. Displaces oxygen from its combination with hemoglobin and forms relatively stable compound carboxyhemoglobin thus leading to hypoxia.( affinity 200 to 300 times greater). CO affinity to myoglobin (40 times greater) may cause direct myocardial depression. Act as chemical asphyxiants produce death due to anaemic anoxia. Interfers with intercellular respiration.

14. ELIMINATION Eliminated through lungs 1% is metabolized into CO2 Not lost through skin, bile, perspiration, urine or faeces. Not absorbed by a body after death

15. SIGNS AND SYMPTOMS

16. Often mistaken for symptoms of influenza or illness caused by contaminated food.. Effects are simply those of suboxia . Bullae are localised over calves, buttocks, wrists and knees by external pressure. Death usually occurs when 80% of Hb is saturated with CO. CO automatism Tendency of the dying victim to wild, erratic, swinging movements inside the room, disturbing clothing and furniture which gives an impression of violent struggle . CO pass from maternal to fetal blood, produce intrauterine death (˃ 10 to 15 %)

17. Blood under the skin and in tissues will be cherry red due to formation of carboxy - haemoglobin .

18. CHRONIC POISONING Headache, confusion Paraesthesia Visual disturbances HTN, Hyperthermia Mental Retardation. Parkinsonism Psychosis

19. TREATMENT Remove patient to fresh air Conscious and breathing, no treatment COHb level >25% should be treated Provide 100% oxygen Endotracheal intubation CO2 should not be given Gastric lavage in early stage Whole blood transfusion Complete rest for 48 hrs

20. POST MORTEM APPEARENCE Cherry red appearance of skin, mucous, conjunctiva, nail bed. Anemic cont.. - color pink Dark coloured victims - masked Color will not be changed by embalming or preservation by formalin During decomposition Cherry red -> dark green -> brown

21. Blistering of skin of dependent area. Congestion of lungs with pink fluid blood Pulmonary edema. Bilateral symmetrical necrosis and cavitation of basal ganglia in putamen and globus pallidus Ring shaped hemorrhages in white matter of brain.

22. CIRCUMSTANCES OF POISONING Suicide is rare Accidental is most common Exposure to exhaust gas of petrol engine Exposure to gas in mines Incomplete combustion of wood, charcoal or coal Homicide is uncommon Unless victim is alcoholic or child

23. SUICIDE BY CO POISONONG

24. CARBON DI OXIDE

25. Features Heavy, colorless gas Faintly sweet odour Atmospheric air 0.033% CO2’ Product of complete combustion of carbon. Seen at manholes, ship holds, old wells Action Not toxic Simple asphyxiant- Preventing tissue from obtaining oxygen.

26. ˃ 5 % - Laboured breathing, Mental confusion ˃ 10 % - Ataxia and unconsciousness ˃ 40 % - Dyspnea, Muscular weakness ˃ 50 % - Dyspnea, Fullness in head, Ringing in ear, loss of muscular power, unconsciousness, coma, death. ˃ 60-80 % - Unconsciousness and rapid death.

27. TREATMENT Artificial respiration Free O2 Cardiac stimulants

28. POST MORTEM APPEARANCE Marked cyanosis Congestion Suffusion of eyes Dilation of the pupils Petechial hemorrhages

29. CIRCUMSTANCES OF POISONONG Accidental

30. HYDROGEN SULPHIDE

31. FEATURES Colorless, heavy, flammable Exposure to lower con. smell of rotten eggs is detected. Formed during decomposition of organic matter containing sulphur . Poisoning due to inhalation ACTION Does not combine with Hb Interferes with cellular respiration by inhibiting the action of cytochrome oxidase. SEWER GAS -  H 2 S + CO 2 + CH 4

32. Great dilution Feeling of dullness and sleepiness, death may occur during sleep Weak concentration Cough, giddiness, nausea, cyanosis of face, muscular weakness… Moderate concentration metabolic acidosis, CNS, respiratory and myocardial depression Death from paralysis of respiratory centre.

33. Chronic low level absorption Reduced lung function Headache Depression Personality changes Chronic eye irritation

34. TREATMENT Patient is removed to fresh air Artificial respiration 100% O2 Excretion of sulphide . Amyl nitrate inhalation and sodium nitrate infusion. POST MORTEM APPEARENCES Rotten egg odour is given off General signs of asphyxia Color of blood, viscera, bronchial secretions is greenish purple

35. THANK YOU IT ALWAYS SEEMS IMPOSSIBLE UNTIL ITS DONE……`!