Poison: Poison is a substance (solid, liquid, or gaseous) which, if introduced in the living body (by enteral or parenteral) or brought into contact thereof, will produce ill health or death, by its local or constitutional effect or both.
TOXICOLOGY: Toxicology is the science dealing with properties, actions, toxicity, fatal dose, detection, estimation, and interpretation of the results of toxicological analysis and treatment of Poisoning.
FORENSIC TOXICOLOGY: It deals with the medical and legal aspects of the harmful effects of poison on the human body, both in living and dead form.
EPIDEMIOLOGY OF POISON
According to WHO, 3 million acute Poisoning with 2,20,000 deaths occur annually. Of these, 90% of fatal Poisoning occur in developing countries.
Pattern of Poisoning depends on a variety of factors, such as
- Locality
- Availability
- Socioeconomic status
- Religious and cultural influence
- Injudicious use of drugs
- Domestic usage
It has been estimated that about 5 to 6 persons per lakh of the population die due to Poisoning per year. Acute Poisoning is one of the most typical causes of emergency hospital admission. Among the adults, females predominate in all age groups, with an evident preponderance in the second or third decade. Acute Poisoning in children is almost always accidental, while in adults, it is mainly suicidal.
CAUSES OF ACCIDENTAL POISONING
- Children intaking- medicines, kerosene, toiletries, etc
- Love philters- aphrodisiacs, mercury, arsenic, etc.
- Drug overdose
- Quack remedies
- Agricultural usage- pesticides, insecticides, rodent killers, fertilizers, etc
- Industrial hazards- asbestosis, silicosis, ammonia, CO, H2S, SO2, etc
- Unhealthy water supply- lead, iron, mercury, etc.
- Food adulteration- preservatives, coloring agents, essence, etc.
- Food poisoning- mushrooms, puffer fish, fungus, marine fishes, etc.
- Insects, snake bite-scorpions, bees, wasps, spiders, ticks, caterpillars, etc.
- Environmental causes- x-ray, radium, lead, fumes, etc.
- Occupational hazards- anthracosis, brucellosis, wood solvents, fabric coloring, etc.
PREVENTION OF ACCIDENTAL POISONING
- Mass education
- Drugs and poisons should be kept in lock
- Should be kept away from food
- All products should be kept in separate containers
- Caps and tops should be appropriately closed
- All containers should be properly labeled
- The label should be read before use
- No drug should be taken in the dark
- Expired drugs should be disposed of properly
- Drugs and chemicals should kept within reach of children
- The kitchen should be well-ventilated
- Children should be taught about food safety
- In industries, air-water pollution should be prevented
- Safety equipment and measures should be provided.
- Old and contaminated food should be avoided.
CLASSIFICATION
Medicolegal Classification of poison –
- Homicidal poison- arsenic, aconite, thallium etc
- Suicidal poison- OPC, endocrine, paracetamol, opium, etc.
- Accidental poison- stated before
- Stupifying poison- datura, cannabis indica, chloral hydrate, ether etc.
- Abortificients- ergot, calotropis, oleander, croton seed, semecarpus etc.
- Aphrodisiacs- cocaine, opium, cannabis, sildenafil, etc
- Infanticidal- madar, yellow oleander, opium, common salt, etc.
- Rare – bacteria, bacillus, insulin, etc.
Symptomatic Classification
- Corrosive
- Strong Acids-
- Inorganic- Sulphuric, Nitric, Hydrochloric acid
- Organic- Carbolic, Oxalic, Acetic, Salicylic acid
- Strong Alkalies- Hydrates and carbonates of sodium, potassium, and ammonium
- Metallic Salts- Zinc chloride, copper sulfate, silver nitrate, potassium cyanide
- Irritant
- Inorganic
- Metallic- Arsenic, Copper, Lead, Mercury, Silver etc.
- Non-metallic- Phosphorus, iodine, chlorine, etc.
- Organic
- Vegetables- Castor, Cannabis, Oleander, Calotropis, etc.
- Animal- Snake, Cantharides, Protamine, Wasp, Bees, etc.
- Mechanical- Powdered glass, Diamond dust.
- Systemic
- Cerebral
- Stimulants- TCA, Amphetamine, caffeine
- Depressants- Alcohol, Anesthetics, Opioids, Sedatives, Hypnotics etc.
- Deliriants- Datura, Belladona, Canabis, Cocaine
- Spinal- Nux vomica, Curare
- CVS- Aconite, Quinine Cyanide, Oleander, etc.
- Peripheral- Conium, Curare
- Miscellaneous- Food poisoning, Botulism, Adulteration, etc.
CRITERIA OF IDEAL HOMICIDAL POISON
- Cheap
- Easily available
- Colorless, tasteless, odorless
- Easily introducing opportunity
- Highly toxic
- Signs and symptoms should resemble a natural disease
- Symptoms should be delayed sufficiently delayed
- No antidote
- No PM changes
- Detection should be difficult
- Rapidly destroyable
CRITERIA OF IDEAL SUICIDAL POISON
- Cheap
- Easily available
- Tasteless, odorless, or pleasant taste
- Easily introducing opportunity
- Highly toxic
- Capable of producing painless death
CRIMINAL USE OF POISON
- To kill
- To cause serious injury
- For robbery or theft
- To rape
- To procure an abortion
- To annoy the victim
- For disfiguring
- For Suicide
- Cattle poisoning
- For perishing devastation
- Pisces poisoning
- Para suicide
ROUTES OF ADMINISTRATION OF POISON
- Inhalation
- IV or IA administration
- IM, SC, or ID injection
- Application to a serous surface
- Application to a wound
- Swallowing
- Through the rectum, urethra, or vagina
- Application to unbroken skin
- Snuffing
ACTION OF POISON
- Local
- Corrosion
- Congestion
- Irritation
- Effect on motor or sensory nerve endings
- Remote
- Shock
- Coma
- Asphyxia
- Organ failure
- Combined
FACTORS MODIFYING ACTION OF POISON
- Quantity- The more quantity, the more sin and symptoms
- Quality- toxicity of the poison
- Physical state- gaseous form is the most dangerous
- Chemical combination- interaction with other drugs or chemical
- Mechanical combination
- Condition of the Body
- Age-old and children are more susceptible
- Sex- female are more prone to fat-soluble poison
- Idiosyncrasy
- Habit- may develop tolerance, may require more amount to develop toxicity
- State of health- co-morbidity may hasten death.
- Cumulative action
- Sleep and stomach condition- empty stomach hastens, sleep causes delay of action
- Route of Poisoning- the intravenous route is the quickest route; next is inhalation.
- Status of excretion- renal failure always causes its worst effect.
TYPES OF POISONING
- Acute- immediate and severe
- Subacute- medium effect
- Chronic- delayed and less effective
- Fulminant – so severe that the patient dies before appearing typical signs and symptoms.
FATE OF POISON
- The more significant portion is expelled from the body by vomiting and purging.
- The absorbed poison is detoxicated in the liver.
- The unaltered portion goes to circulation and has a harmful effect on the tissue until it is destroyed or made harmless by the kidney and muscle.
- Some inorganic poisons like arsenic and anti are retained in specific tissues.
- Some poisons, like chloroform, disappear due to evaporation or oxidization.
ROUTES OF ELIMINATION
- Unabsorbed poison is eliminated through vomiting and purging
- Absorbed poison is mainly excreted by the kidneys and skin
- Other routes are Bile, milk saliva, mucus, and serous secretions.
DIAGNOSIS OF POISONING
In the Living
It may vary from poison to poison. But suspicion should arise when history is given like-
Symptoms appear suddenly
Symptoms appear just or within a short period of taking food or drink
Symptoms are uniform
Symptoms rapidly increase in severity
When several persons taking the same substance show the same symptoms
Discovery of poison in food or drink taken
Odors of poison in breath, vomiting, and clothing.
Color of poison in clothing
Presence of poison or its metabolites in sweat, urine, saliva, or stool.
The following groups of signs and symptoms are suggestive of Poisoning
if ( occurs) sudden onset of –
- GI upset- nausea, vomiting, diarrhea
- Coma with change of pupil
- Convulsion
- Delirium
- Jaundice with hepatic coma or precoma
- Huge salivation
- Frothy discharge per mouth
- Paralysis, particularly LMN type
- Oliguria with proteinuria or hematuria
- Persistent cyanosis
TYPES OF POISONING
- Acute Poisoning is caused by an excessive single dose or several smaller doses in a short interval of time, causing severe signs and symptoms.
- Chronic Poisoning is caused by smaller doses over some time, causing gradual worsening.
- Subacute Poisoning- shows features of both acute & chronic Poisoning or in between them.
- Fulminant Poisoning- occurs in massive dosing, causing death rapidly, even sometimes before showing signs & symptoms.
- Parasuicide- is a conscious, manipulative, often impulsive act undertaken to get rid of an intolerable situation.
COMMON S/S OF POISONING
- GI upset- nausea, vomiting, diarrhea, abdominal pain
- Coma with change of pupil
- Convulsion
- Delirium
- Jaundice with hepatic coma or precoma
- Huge salivation, sweating
- Frothy discharge per mouth
- Paralysis, particularly LMN type
- Oliguria with proteinuria or hematuria
- Persistent cyanosis
POSTMORTEM FINDINGS OF POSONING
(a) External Appearance
- Color on clothes and skin
– Sulphuric and HCl acid—grey to black
– Nitric Acid—brown
– Carbolic acid—grayish white
– Mercuric chloride – bluish white
– Chromate—orange
PM Staining
-Phosphorus—yellow
– Copper– dark brown
– CO—cherry red
– Nitrites, Aniline, Bromates, Chromates—chocolate
- Smell about mouth
– Phosphorus, Arsine gas—garlic like
– Ethanol, Chloroform—sweety or fruity
– Paraldehyde, Chloral hydrate—acrid
– H2S, Mercaptan—rotten egg
– Zinc phosphide—fishy
– OPC, Endrine—kerosine
- Natural orifices- nostrils, mouth, vagina, rectum, urethra, etc.
- Skin- color, hydration, sweating, bruise with abrasion etc.
- Marks of violence
- Signs of struggle
- PM Temperature
(b) Internal Appearance
- Smell
- Mouth and throat- corrosion, ulceration, inflammation, bleeding, teeth whitening, etc
- Esophagus– corrosion, ulceration, bleeding, perforation, stricture, dilatation, etc.
- Stomach and its contents- corrosion, ulceration, bleeding, perforation, hyperemia, tumor, etc.
- Duodenum and intestines- corrosion, ulceration, bleeding, perforation, stricture, hyperemia secretion, stenosis, tumor, etc.
- Upper respiratory tract- corrosion, ulceration, bleeding, perforation, stricture, hyperemia, tumor, etc
- Liver, Lungs, heart congestion, hyperemia, softening, secretion, etc.
- Pleura, peritoneum, and other mucus membranes- corrosion, ulceration, petechial bleeding, perforation, hyperemia, etc.
- Kidneys and Urinary Bladder- congestion, softening, hyperemia, colored urine, blood clots, stones, tumors, etc.
- Vagina and uterus- corrosion, ulceration, bleeding, perforation, stricture, hyperemia, fibroid, etc.
(c) Chemical Analysis
COLLECTION IN LIVING CASES
- Stomach wash
- Vomitus
- 10 ml. blood (sodium fluride as anticoagulant)
- Urine
- Stool
METHOD OF ANALYSIS
- Separation
- Purification
- Analysis
- Chemical Reaction
- Manual Spectrometry
- Digital Spectrometry
- TLC (thin layer chromatography
- Gas Chromatography (GC)
- GC-Mass Spectrometry (GC-MS)
- UV Spectrometry
TOXICITY
Therapeutic Index- TI is the ratio of the toxic dose to the effective dose of the drug.
Lethal Dose- LD is the smallest dose recorded as fatal to a healthy person.
Interpretation of Toxicological Analysis-
The following factors should be considered during the interpretation of the toxicological analysis report-
- Age
- Weight
- Presence of natural disease
- Presence of trauma
- Hypersensitivity
- Presence in natural source
TOXICITY MEASUREMENT
< 5mg/kg – 6 (super toxic)
5 to 50 mg/kg – 5 (extremely toxic)
50 to 500 mg/kg – 4 (very toxic)
0.5 to 5 gm/kg – 3 (moderate toxic)
5 to 15 gm/kg – 2 (slightly toxic)
>15 gm/kg – 1 (non-toxic)
CAUSES OF FALSE NEGATIVE
- Eliminated by
- Vomiting
- Purging
- Expiration
- Urination
- Detoxification, Oxidation, Conjugation & Metabolism
- Faulty preservation
- Wrong or insufficient sample
- Minimal lethal dose
- Faulty technique
- Biological toxin- insulin, corticosteroid, etc
- Venom
CAUSES OF FALSE POSITIVE
- Natural sourcing- As., Lb., Hg. Etc
- Faulty preservation
- Faulty technique
- Mixing during any stage of examination
- Manipulation
- Imbibitions
DIAGNOSIS OF POISONING
IN THE LIVING
- Symptoms
- Signs
- Collection
- Vomitus
- Blood
- Urine
- Stomach content
PM APPEARANCE
- External
- Internal
- Chemical analysis
- Experiments on animals
- Motives
- Circumstantial evidence
DUTIES OF MEDICAL PRACTITIONER IN POISONING
Medical Duties
- Resuscitation
- Diagnosis
- Treatment
Legal Duties
- Particulars of the patient.
- Confirmation of Diagnosis.
- After confirmation, refer the patient to the hospital.
- Collection of suspected materials.
- If the doctor is Govt, MO, he should report to the police whatever the nature of Poisoning.
- If the doctor is a private practitioner, he is not bound to inform if it is a suicidal one. But if it is a homicidal case, he is bound to notify the police or magistrate.
- If the IO summons the practitioner, he is bound to provide all necessary information requested by the investigation officer.
- If the patient is severe, he must arrange to record the dying declaration.
- If the patient dies, he should not issue any death certificate, but he should inform the police.
- In case of food poisoning, public health authorities must be notified.
TREATMENT OF POISONING
Immediate resuscitation (ABCD)
- Airway- opening, neck extension, cleaning, endotracheal intubation, and prevention of tongue falling.
- Breathing- o2 inhalation, artificial respiration, mouth-to-mouth breathing.
- Circulation- IV fluid, blood when necessary, cardiac massage
- Depression of CNS- should be corrected
Removal of unabsorbed poison
- Contact poisons- removal of clothing, washing with profuse water with/without soap, neutralization by specific chemical
- Inhaled poisons- removal to fresh air, o2Inhalation, artificial respiration, Nikethemide
- Injected poison-tight ligature, multiple excisions, and sucked out, neutralization by particular chemical.
- Ingested poisons
- Gastric lavage
- Emetics
Administration of Antidote
- Physical antidote
- Chemical antidote
- Physiological antidote
- Pharmacological antidote
- Serological
Elimination of poison by excretion
- Renal excretion
- Purging
- Whole bowel irrigation
- Diaphoretics
- Forced Diuresis
- Peritoneal dialysis
- Hemodialysis
- Charcoal hemoperfusion
Symptomatic treatment
Follow up
Rehabilitation
