FORENSIC MEDICINE AND TOXICOLOGY

1. FORENSIC MEDICINE AND
TOXICOLOGY SEMINAR

2.  POISON
Substance which when
administrated , inhaled
Or ingested is capable of acting
deleteriously on human body.
Medicine in a toxic dose = POISON
Poison in a small dose = MEDICINE

3.  There are 6 major groups of poisons.
1. Corrosives:
 Acids :
 Inorganic : H2SO4,HNO3,HCl.
 Organic : CH3COOH, Carbolic, Oxalic acid
 Alkalies: NH3,Salts of Na, Ca, K etc.
2. Irritants :
 Inorganic elements :
 Non metals : P, Halogens
 Metallic : (Heavy metals : As, Pb, Hg, Cu, Fe, etc.

4.  Organic toxins :
 Irritant plants : Castor , Calotropis, Croton, Abrus
 Bites and stings : Snakes, Scorpion, Spider, Bees,
Wasp
3. Neurotoxic poisons :
 Cerebral
 Somniferous : Opium and Opiates.
 Inebriants : Alcohols, Barbiturates ,
Benzoidazepines
 Deliriants : Datura, Cannabis, Cocaine

5.  Psychotropics :
 Antidepressants : Amphetamines, Tricyclics
 Neuroleptics : Phenothiazines , thioxanthines,
Butyrophenones
 Hallucinogens : LSD , Phencyclidine..etc
 Spinal :
 Stimulant : Strychine
 Depressants : Gelesemine
 Peripherally acting : Hemlock, Curare, etc..

6. 5. Cardiovascular Poisons:
 Antihypertensives
 Anticoaglants
 Cardiotoxic Poisons: Aconite,
Olender, Odallum, Digitalis..etc
6. Asphyxiants:
 CO, HCN, MIC, Tear gases

7. 7. Miscellaneous Poisons :
 Pesticides
 Food poisons : Microbes, Mushroom ,
Fish, Chemicals
 Pharmaceuticals : Analgesics,
Antipyertics, Antibiotics, Sedatives,..etc
 Substance of abuse.

8. USUAL FATAL DOSE RATING
Less than 5 mg/ kg 6 (super toxic)
5 to 50 mg/kg 5(extremely toxic)
51 to 500mg/kg 4(very toxic)
501 mg/kg-5 g/kg 3(moderately toxic)
5.1 g/kg-15 g/kg 2(slightly toxic)
More than 15 g/kg 1(practically non toxic)

9. 1. Gaseous or vapourous form
 Inhaled in gaseous and vaporous form
 Involves a volatile substance, gas,dust,smoke.
 Industrial poisoning are
benzene,toluene,acetone,methyl chloroform,carbon
tetra chloride
 From home itself hydrogen sulphide and methane
are green house gases .

10. 2. Injection onto blood vessels
3. Intramuscular, subcutaneous and
intradermal injection
4. Application to a wound
5. Application to a narrow surface
6. Application to a broncho-tracheal mucus
membrane
7. Introduction into stomach

11. 8. Introduction to natural orifice
 To rectum, vagina, ureter etc,...
 Examples:- aspirin, barbiturate, oro hydrates
9. Application to unbroken skin
 Organic phosphates, nicotine which penetrate into the skin and
cause death
 Others are phenol and derivatives of enderin methyl salicylate,
mercury tetra acetate lead and alkalite compounds and hydra
cyanine compounds
 Hormones such as estrogen , progesterone, and testosterone
 Vitamins like D and K

12. 1. Quantity
A large quantity of poisons if it is orally taken cause
excessive vomiting and giddiness
Examples:- alcohol , copper sulphate
2. Form :-
a) Physical state:- poison act rapidly when gaseous
state, less in liquid
Solid:- depends upon solubility
b)Chemical combination :- combined from are toxic.
Ex:- arsenic - non poisonous, its salts are poisonous

13.  Certain poisons which are not soluble in water may be
soluble in acid secretion of stomach and absorbed into
the blood ex:- lead carbonate and copper
arsenite
c) Mechanical combination :- The action of a poison
may be altered if combined mechanically with inert
substances ex:- small dose of conc. Mineral acid
produces corossive action but the same dose largely
diluted with water is harmless

14. 3). Mode of administration:- The rapidity of the action
is in the order described under routes of
administration . As a rough guide, its the active dose
by the mouth is considered as unit, the rectal dose is
about one and half to two and hypodermic dose about
one fourth .
A lethal dose is usually more than the
maximum medicinal dose
4). Condition of the body:- a) age: poisons have greater
effects at the two extremes of age

15. b) Idiosyncrasy:- Certain people are sensitive for
certain drugs and even articles of diet
c) Habit:- The effect of certain poisons decreases
with habitation such as opium, alcohol, tobacco
d) State of health :- A healthy person tolearates
better than diseased. General debility sensitivity
chronic or disbling disease may cause death of a
person to a dose that is ordinarily safe

16. e) Sleep and intoxication :- The action of a poison
is delayed if the person goes to sleep .
Soon after taking it , the action is also delayed.
f) Cumulative action :- Poisons which are
eliminated slowly may accumulate in the body
when given in repeated doses for a long time and
may ultimately produce symptoms of poisons

18. 1. Stablization
2. Evaluation
3. Decontamination
4. Antidote administration
5. Nursing and Psychiatric care

19.  Initial survey should always be directed as
assessment and correction of life threatening
problem is present.
 Attention must be paid to
 1. Air way ABCD
 2. Breathing
 3.Circulation
 4. Deperssion of CNS.

20.  Symptoms of air way obstruction :
Dyspnoea ( breathlessness) ,air hunger and
hoarseness.
 Signs : Stridor, intercostal and substernal
retractions, cyanosis, sweating.
 Increasing metabolic acidosis in the presence of a
normal PaO2 suggests a toxin or a condition.
 1. Decreases oxygen carrying capacity ( Eg: CO)
 2. Reduces tissue oxygen (Eg: CN-)

21.  Indications :
The immediate need for assisted ventilation
has to be assessed clinically, but the
efficency of ventilation can only be gauged
by measuring the blood gases.
 1. Retention of CO2 (PaCO2 > 45mmHg)
 2. Hypoxia( PaCO2 < 70 mmHg) inspite of
oxygen being given by facemask.

23.  A simple method of assessing
respiratory status consists of
determining the minute
volume by Wright
Spirometer. If this is more
than 4 l/min there is no need
of ventilation. How ever , it
must be borne in mind that
ventilatory function can
fluctuate and may deteriorate
suddenly.

24. FAILURE OF RESPIRATORY
CENTRE
FAILURE OF RESPIRATORY
MUSCLES
Antidepressants Neuromuscular blocking
agents
Antipsychotics Nicotene
Ethanol Organophosphates
Opiates Shell fish poisoning
Sedatives Snake bite ( Cobra)
Strychnine

25. Amphetamines
Atropine
Cocaine
Salicylates

26.  Tachycardia & Normotension
1. Antihistamines
2. Caffeine
3. Cannabis
4. Iomotil (Atropine & diphenoxylate )
 Thyroxine
 Tachycardia & Hypotension
1. Carbomonoxide
2. Cyanide
3. Phenothiazines
4. Theophylline

27.  Tachycardia and Hypertension
1. Amphetamines
2. Cocaine
 Phenylpropylamine
 Bradycardia & Hypotension
1. Clonidine
2. Levodopa
3. Organophosphates
4. Opiates
5. Tricyclic Antidepressants

28.  Bradycardia & Hyper tension
1. Phenylpropylamine

29.  One of the most important cause for coma
is acute poisoning.
 Substance which induce coma
1. CNS Depressants
2. Asphyxiants
3. Hypoglycemics
4. Sedative hypotonics

30.  Commonest method for assessing coma is based
on Glassgow Coma Scale, the European
Association of Poison Centre and clinical
toxicologists, very useful for the trauma patients
.
 Other Comphrenssive Level Of Consciousness
Scale ( CLOCS), Coma Recovery Scale, Reed’s
Classification etc...but predictive value of all
these scale remains ascertained.

31.  Hoffman and Gold frank reviewed
extensive data from 1966 to 1994 on the
management of comatose patient and came
to the conclusion that in every case identity
of poison was unknown the follwing
substance can be used intravenously.

32.  Dextrose- 100 ml of 50% slon.
 Thiamine (Vit B1) - 100 mg
 Naloxone - 2 mg

33.  Used in case of metabolic acidosis , it is necessary to
calculate anion gap anion gap is calculated by this :
(Na* + K* -- HCO3- + Cl- )
 Normally this translate as : 140-( 24+104)=12mmol/L
 Range 12 to 16 mmol/L

34.  If the anion gap is more than 20 mmol/L , a
metabolic acidosis is present regardless of
serum bicarbonate concentrate.
 Several poisons are associated with
increasesd anion gap (Gap acidosis ) , while
others do not alter it (Non Gap acidosis)

36.  The various methods of removal of poison
from gastrointestinal tract include.
1. Emesis
2. Gastric lavage
3. Catharsis
4. Activated charcoal
5. Whole bowel irrigation

37.  Only recommended that
ipecac or syrup of
ipecacuanha for inducing a
poisned patient to vomit.
 Source : Root of a small
shrub grows in West Bengal
 Active Principles :
Cephaeline, emetine , and
traces of psychotrine.

38.  Indications:
Conscious and alert poisoned patient who has
ingested a poison not more than 4 to 6 hrs earlier.
 Mode of action :
Local activation of peripheral sensory receptors in
GIT.
Central stimulation of the chemoreceptor trigger zone
with subsequent action on central vomiting centre.

39.  Dose
30 ml – Adult
15 ml - Child
Followed by 250 – 500 ml of water. Patient
should be sitting up. If vomiting does not
occur with in 30 minutes repeat the same
dose. Still no effect perform stomach wash
not only poison but also ipecac.

40.  Contraindications:
Relative:
1. Very young , or very old person
2. Pregnancy
3. Bleeding diathesis
4. Ingestion of cardiotoxic poison
5. Time lapse of more than 2 – 3 hrs.

41.  Absolute
1. Convulsions
2. Impaired gag reflex
3. Coma
4. Foregin body ingestion.
5. Corrossive ingestion
6. Ingestion of petroleum distillates
7. All poisons are emetic in nature

42.  Complications
1. Cardiotoxicity
Arryhthmias
Myocarditis
2. Aspiration Pneumonia
3. Oesophageal mucosal or Mallory – Weiss tears

44.  Indications:
 Recommended mainly for the patients who
have ingested a life threatening doses
 Lavage beyond this period may be
appropriate only in the presence of gastric
concertions, delayed gastric emptying or
sustained release preprations.
 Can able to lavage upto 6 – 12 hrs

45.  Precautions:
 Never undertake lavage in a patient
who has ingested a non toxic agent or a
non toxic amount of toxic agent.
 Never use a lavage as a deterrent to
subesequent ingestion. Such a notion is
barbaric, besides being incorrect

46.  Contraindications
 Relatives:
1. Haemorrohagic diathesis
2. Oesophageal varices
3. Recent surgery
4. Advanced pregnancy
5. Ingestion of alkali
6. coma

47.  Absoulte
1. Marked hypothermia
2. Vomiting
3. Unprotected air way in coma
4. Ingestion of acid
5. Petroleum distillate
6. Sharp substances

48. 1. Explain the exact procedure to the patient and obtain his
consent, if he is refusing won’t do.
2. Endotracheal intubation must done for comatose patients
3. Place the patient’s head down on his left lateral side 20
degree tilt on left on the table
4. Mark the length to be inserted
 for adult - 50 cm
 for children - 25 cm

49. 4. In india Ewald tube is used, a soft rubber tube
with funnel at one end
5. Diameter corresponds to 36 – 40 french size
6. In a child it should be about 22 -28 french size

50. 7. Preferred route of insertion done by oral.
8. Lubricate the inserting end by vaseline or
glycerine
9. Use a mouth gag so patient wont bite it.
10. By teting the Ph aspirate if it is acidic then
it is properly positioned

51.  Small aliquots of liquid
 In adults 200-300 ml of aliquots of
warm 38 *c saline or plain water is
used
 This is avoided in children because of
 1. Inducing hyponaterimia
 2. Water intoxication

52. 11.Lavage should be continued until no
further particulate matter is seen,
efferent lavage should be clear
12. End of the lavage pour a slurry of
activated charcoal in water an
appropriate dose of an ionic catheritic
ino stomach and remove tube.

53.  Complications
1. Aspiration Pneumonia
2. Laryngospasam
3. Vagal inhibition
4. Cardiac arrhythmias
5. Perforation of stomach
6. Perforation of oesophagous

54. POISON SOLUTION
Most poisons Water or Saline
Oxidisable poisons Pottassium
permanganate
Cyanides Sodium
thiosulphate
Oxalate Calcium gluconate

55.  Mainly two groups
1. Ionic or saline
 Alter physciochemical forces with in
the intestinal lumen
 Leads to osmotic retention of fluid
which activates motility reflexes and
enhance explusion

56. Doses
1. Magnesium citrate = 4 ml / kg
2. Magnesium sulphate = 30 g
3. Sodium sulphate = 30 g

57. 1. 2. Sacchrides
Sorbitol in case of adults.
better efficient
can be used in young children
Dose : 50ml of 70% solution

58.  The various methods of eliminating adsorbed poison
from the body include
 Forced diuersis : only alkaline diuresis recommended
today for salicylates, barbiturates etc...
 Extracorporeal Techniques
 Heamodialysis
 Heamoperfusin
 Heamofiltration
 plasmapheresis

59.  Due to the poisoning Chronic kidney
disease cause the kidney to lose their
ability to filter and remove waste and extra
fluid from the body.
 Heamodialysis ia a process that use a man
made dialyser to remove wastes such as
urea from the blood.

61.  Dialysis is very effective in
1. Lithium
2. Phenobarbitone
3. Salicylates
4. Ethyl alcohol
5. Barbiturate
6. Chloral hydrate
7. Quinne
8. Strychine

62.  Defnition :
 Antidotes are the substance which
counter act the effects of poisoning
 Classification:
 1. Physical Antidotes : Neutralise substance by
mechanical action.
 2. Chemical antidotes : Neutralise the poison by
chemical action.

63.  MORHOLGICAL FEATURES
 Fine
 Black
 Odourless
 Tasteless powder
 SOURCES
 From burning wood
 Coconutshell , bone, sucrose , rice starch

64.  FEATURES
 Particles are small , but have extermly
surface area
 Each gram of activated charcoal works
out a surface area of 1000 sqm
 Helps in adsorbtion of poisonous
substances.

65.  MODE OF ACTION
 Decreases the absorption of variety of poisons by
adsorbing them on its surface.

67.  DOSE
 1 G/kg body weight
 50-100 g in adults
 10-30 g in a child
 PROCEDURE
 Add four to eight times the quantity of water to the
calculated dose of activated charcoal and mix together
to form slurry
 Administrated to patient as lavage.

68. Act as a proective white coating and
doesn’t allow the poison which
cause any damage
Eg: Milk, Egg white, Mineral oil,
Milk of magnesia Aluminium
hydroxide gel

69.  Consists of
 1. Activated charcoal or burnt toast of 2 parts
 2. Milk of magnesia
 3. Strong tea or tannic acid

70.  Dialysed iron : Neutrlise Arsenic
 Albumin : Percipitate Mercuric chloride
 Common salt : decompose Silver nitrate
 Copper sulphates : To percipitate
Phosphurs

71. Complex agent and metal is more water
soluable than the metal itself, results in the
higher renal excretion of complex.
Examples :
1. BAL- British Anti Lewisite
2. EDTA- Ethylene Diamine Tetra Acetic
Acid
3. Pennincilamine

72. For As, Pb, Cu, Au..etc
Dose = 3-4 mg/kg
Shouldn’t use when liver is
damaged
May induce hemolyisis

73.  For Pb, Hg, Cu, Co, Cd, Fe, Ni...etc
 Dose
 25-35 mg/kg in 250- 500 ml 5% dextrose over a
period of 1-2 hr daily and repeated 2*3 days

74.  Hydrolysed product of
penincilin
 Chelating Which maximum
shows efficency of heavy metals
 DOSE
 30 mg/kg 2 mg/day in 4 divided
doses orally for 7 days

75.  IF A CASE OF POISON IS ACCIDENTAL OR
SUCIDAL IN NATURE THE ATTENDING
DOCTOR IS UNDER NO LEGAL
OBLIGATION TO NOTIFY THE POLICE IN
CASE HE IS WORKING IN A PRIVATE
HOSPITAL BUT IF THE PATIENT DIES THE
POLICE HAS TO BE INFORMED, DEATH
CERTIFICATE MUST NOT TO BE ISSUED.

76. DOCTORS WORKING IN
GOVT HOSPITALS ARE
REQUIRED TO REPORT
ANY CASE OF POISONING
REGARDLESS OF NATURE
TO POLICE

77.  ALL THE CASES OF HOMICIDAL
POISONING (DEFINITE OR SUSPECTED)
MUST BE COMPULSORLY REPORTED TO
POLICE AS PER SEC 39 OF THE CRIMINAL
PROCEDURE CODE (CrPc) FAILURE TO
DO SO WILL MAKE HIM CULPABLE
UNDER SEC 176 OF THE INDIAN PINEAL
CODE (IPC)

78.  IF THE POLICE REQUIRE INFORMATION
ON ANY CASE OF POISONING WHICH IS
EITHER SUICIDAL OR HOMICIDAL IN
NATURETHE ATTENDING PHYSICIAN
HAS TO DIVULGE IT THERE IS NO SCOPE
FOR PROFESSIONAL SECRECY IN SUCH
MATERS (175 CrPc) IF INFORMATION IS
WITHELD OR WRONG INFORMATION IS
PROVIDED THE DOCTOR BECOME

79.  EVERY EFFORT MUST BE MADE BY
ATTENDING DOCTOR TO COLLECT
AND PRESERVE EVIDENCE
SUGGESTIVE OF POISONIG
DELIBERATE OMISSION TO DO SO
CAN ATTRACT PUNISHEMENT
UNDER SEC 201 IPC

80.  COLLECT STOMACH WASHINGS
VOMITUS FAECES
CONTAMINATED FOOD ETC..
DESPATCH THE SAME FOR
CHEMICAL ANALYSIS OF THE
NEAREST FORENSIC
LABORATORY

81.  IF A POISONED PERSON IS CONSCIOUS BUTVERGE ON
DEATH RECORD A DYING DECLERATION RELATINGTO
THE CIRCUMSTANCES IT IS PREFERABLETO CALL A
MAGISTRATE FORTHIS PURPOSE BUT IF DEATH
APPEARS IMINENT OR IFTHERE IS LIKELIHOOD OF
DELAY OF MEGISTRATETHE ATTENDING DOCTOR
MUST HIMSELF RECORD DECLEARATION AS PER
SCTION 32 CLAUSE 1 AS PER INDIAN EVIDENCEACT
EVENWHEN A DECLERATION ISTAKEN BY MAGISTRATE
PRESENCE OF A DOCTOR DESRIBLETO CERTIFY DYING
VICTIMWAS IN POSSESIONOF HIS SENSESAND HERE
WAS NO CLOUDING JUDGEMENT OR COHERENCE
WHICH IS SOMETIMES ENCOUNTERED INTHE FINAL
MOMENTS ON DEATH

82.  IF A PATIENT DIES BEFORE THE
EXACT DIAGONOSIS COULD BE
MADE OUT OR HE BROUGHT DEATH
TO THE HOSPITAL THE DUTY
DOCTOR MUST NOTIFY THE POLICE
WHOWILL ALL PROBABLITY ORDER
AN AUTOPSY TO BE DONE. DEATH
CERTIFICATE MUST NOT BE ISSUED

83.  DETAILED WRITTEN RECORDS
SHOULD BE MADE WITH
NRESPECT TO EVERY CASE OF
POISONING AND KEPT IT IN SAFE
CUSTODY

84. IF A DOCTOR COME ACROSS
AC CASE OF FOOD POISONING
FROM A PUBLIC EATERY HE
MUST NOTIFY PUBLIC HEALTH
AUTHORITY CONCERNED