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FORENSIC MEDICINE & TOXICOLOGY - Enhanced Chapter-wise Bullet Notes
References: KS Narayan Reddy 36th Ed. | Gautam Biswas | Parikh | Dikshit
(GB) = Points added from Gautam Biswas
CHAPTER 1: MECHANICAL INJURIES
Q1. ROAD TRAFFIC ACCIDENTS (RTA)
Pedestrian Injuries (3 phases):
- Primary/First impact: Vehicle bumper strikes legs - produces "bumper fracture" (tibia/fibula) at bumper height; "Tyre tread abrasion" - parallel linear abrasions
- Secondary/Second impact: Body thrown onto bonnet/windscreen - head, chest, trunk injuries; "Fender fracture"
- Tertiary/Third impact: Body hits ground - scattered abrasions, contusions, lacerations
Occupant Injuries (inside vehicle):
- Steering wheel injuries: Chest wall contusions, rib fractures, cardiac contusion
- Dashboard injuries: Knee injuries, femur fractures, acetabular fractures
- Windscreen injuries: Dicing injuries - multiple small square lacerations on face from tempered glass (pathognomonic of RTA)
- Seatbelt injuries: Contusions/bruising in belt distribution; "Seatbelt syndrome" - transverse bruise across abdomen/chest
- Whiplash injury: Hyperextension-flexion injury of cervical spine in rear-end collision
- Airbag injuries: Abrasions to face, arms from airbag deployment
Motorcyclist Injuries:
- Decapitation by wire/cable (Garrotte-type)
- Helmet protects skull but "Ring fracture" of base of skull can occur
- "Spurring of tyres" - distinctive tyre marks
Medicolegal Duties of Doctor in RTA:
- Treat the patient (primary duty - save life)
- Inform police (MLC - Medicolegal Case registration)
- Preserve all clothing/evidence without cutting through injuries
- Document injuries accurately with size, shape, nature, site
- Issue MLC certificate/wound certificate
- Do not alter or destroy evidence
- Maintain secrecy - do not disclose to media/press
- Cooperate with police investigation
- Prepare for court testimony if required
- If death occurs - inform police, do not disturb body, facilitate inquest/postmortem
Q5. FIREARM INJURIES
Classification of Firearms:
- Smooth Bore (Shotguns): Single/double barrel; uses pellets/shots; Gauge = number of lead balls fitting the bore required to weigh 1 pound
- Rifled Bore: Spiral grooves inside barrel; impart spin to bullet; Pistol, revolver, rifle, carbine, machine gun; Classified by calibre (diameter of bore in inches or mm)
- By Muzzle velocity: Low velocity (<600 m/s) - pistols, revolvers; High velocity (>600 m/s) - rifles, military weapons
Entry Wound Features:
- Circular/oval shape (oval if bullet strikes obliquely)
- Inverted/inturned edges (skin pushed inward)
- Abrasion collar (Graze collar): ring of abrasion surrounding entry wound; caused by bullet rotating and abrading skin; width indicates angle of entry; does NOT occur at exit wound (pathognomonic of entry wound)
- Contusion collar/Bruising ring - bluish-red bruising around wound
- Grease/dirt collar - ring of dirt/lubricant wiped off bullet
- Singeing, blackening, tattooing - depends on range
Range vs. Features:
- Contact wound: Star-shaped/cruciform laceration; burning/charring; smoke/soot in wound; muzzle imprint; cherry red tissues (CO)
- Near/Close (<15 cm): Singeing of hair; blackening/soot deposit; tattooing/stippling present
- Intermediate (15-60 cm): No singeing; tattooing/stippling present; no blackening
- Long (>60 cm): Clean punched-out entry wound + abrasion collar only; no other marks
Exit Wound:
- Larger than entry
- Irregular, stellate/lacerated
- Everted margins
- NO abrasion collar
Wound Ballistics:
- Temporary cavity formation; Permanent cavity; Yaw and Tumbling
- Fragmentation; KE = ½mv² - higher velocity = exponentially more energy deposited
- Bullet embolism: Rarely, bullet may travel in blood vessel
(GB) Cartridge of Smooth Bore Firearm (Shotgun) - Components:
- Brass base cap - contains primer/percussion cap
- Powder charge - propellant (smokeless powder)
- Wad - plastic/cardboard disc; separates powder from shot; seals gas; gives characteristic wound at intermediate range
- Shot pellets - multiple lead balls (buckshot, birdshot)
- Overshot card/wad - closes cartridge
- Plastic/cardboard casing (hull)
Q10. ABRASIONS
Classification of Abrasions:
- Scratches/Linear abrasions: By sharp point dragged along skin
- Graze/Sliding/Friction abrasion: Caused by fall on rough surface; base shows parallel lines indicating direction
- Pressure/Crushing abrasion: Due to blunt impact; may show pattern of causative weapon ("patterned abrasion")
- Impact abrasion: Due to perpendicular blunt force impact
Age Estimation:
- Fresh: Red, moist, weeping serum
- 12-24 hrs: Surface dries, yellow/brown crust forms
- 2-3 days: Scab becomes dark brown/hard
- 4-7 days: Scab begins to lift at margins
- 1-2 weeks: Scab falls off, pink scar remains
- 2-4 weeks: Scar fades completely
(GB) Contusion/Bruise - Classification:
- Intradermal bruise: Immediate subepidermal layer; sharp defined edges; from patterned object
- Subcutaneous bruise: In subcutaneous fatty layer; blurred edges; MOST COMMON type
- Deep bruise: Deeper than subcutaneous; may take hours to 1-2 days to appear at surface (delayed bruising)
Factors affecting bruise appearance:
- Age: Easily produced in children and elderly
- Sex: More common in females
- Site: More prominent at bony prominences; on loose skin (scrotum, eyelids); less on thick skin (palms/soles)
- Natural disease: Easier bruising in scurvy, hemophilia, purpura
- Complexion: More visible in fair skin
Age of Bruise (VIBGYOR mnemonic):
- Fresh: Red (Oxyhaemoglobin)
- Few hrs to 3 days: Violet/Blue (Deoxyhaemoglobin)
- 4-5 days: Brown (Haemosiderin)
- 5-6 days: Green (Biliverdin)
- 7-12 days: Yellow (Bilirubin)
- ≥2 weeks: Normal
- Note: In subconjunctival haemorrhage - colour changes NOT seen
Ectopic/Migratory Bruise:
- Blood at point of impact tracks down via fascial planes and appears elsewhere
- Anterior cranial fossa fracture → Raccoon's eye (periorbital ecchymosis)
- Middle cranial fossa fracture → Battle's sign (mastoid ecchymosis)
Parallel (Railway line/Tram-line) Bruise:
- Caused by blows with rod/stick/whip
- Produces two parallel linear haemorrhages with normal skin in between
- Mechanism: Weapon compresses skin ridge (no vessel damage there) but marginal dermal vessels rupture due to traction
Types of Lacerated Wounds (Mnemonic: CATSS):
- Split laceration: Blunt force at bony prominence; "incised-looking" laceration; seen at scalp, forehead, shin
- Stretch laceration: Overstretching of skin; seen in run-over injuries, compound fractures
- Avulsion laceration: Tangential/shearing force; leads to Flaying, Degloving, Amputation
- Tear laceration: Object hits and skin pulled back (e.g., car door handle)
- Cut laceration: Heavy cutting weapon (axe, chopper); underlying bone fracture also occurs
Self-Inflicted/Fabricated Injuries:
- Definition: Wounds produced deliberately on own body or with consent
- Sites: Front of forearm, outer upper arm, front of chest/abdomen, outer thighs
- Features: Incised, multiple, superficial, parallel; clothes usually NOT cut
- MLI: To make false charges of assault; convert simple to grievous injury; allege rape; avoid duties
Hesitation Cuts:
- Tentative, superficial cuts before final decisive cut in suicide
- Multiple, parallel, superficial; on accessible parts
- Sites: Front of wrist, front of elbow, front and sides of neck
- Indicates deeper at beginning, superficial at end
SKULL FRACTURES
(GB) Types (Mnemonic: Love Can Do Problem, Girls Please Be Serious):
- Linear fracture - most common; thin line; no displacement
- Comminuted fracture - multiple fragments
- Depressed fracture - bone pushed inward
- Pond fracture - circular dent; ping-pong fracture; in infants/children/forceps delivery; outer table fractures, inner table intact
- Gutter fracture - groove by tangential bullet
- Perforating fracture
- Basilar fracture
- Sutural fracture
(GB) Hinge fracture (motorcyclist fracture):
- Divides entire base of skull into two parts
- Fracture of middle cranial fossa
- Seen in motorcyclists
(GB) Signature fracture:
- Depressed fracture where shape of depression corresponds to striking surface of weapon
- Helps identify weapon; shows how violence was applied
(GB) Subdural Haemorrhage:
- Bleeding between dura and arachnoid (subdural space)
- Vessels: Rupture of bridging/communicating veins; dural venous sinus tears
- Site: Fronto-temporal; preserves contours of cerebral convolutions
- Types: Acute (<3 days), Subacute (4-21 days), Chronic (>3 weeks - seen in infants and elderly)
- CT scan: Concavo-convex opacity
- MLI: In battered baby syndrome - SDH is the MOST CONSISTENT feature
(GB) Heat Haematoma:
- Artefact (NOT a vital phenomenon) - seen in skull exposed to tremendous heat
- Resembles extradural haematoma (EDH)
- Features: Soft friable clot, light chocolate brown, sickle shaped, honeycomb; bilateral; parieto-temporal
- Contains up to 120 mL blood; eggshell fracture present; crosses suture lines (unlike EDH)
BURNS (Additional from GB)
Degrees of Burns:
- 1st degree: Superficial; epidermal only; extremely painful (nerve endings intact)
- 3rd degree: Painless - nerve endings destroyed (Wilson's burns distinction)
Rule of Nines:
- Head and neck: 9%
- Each upper limb: 9% (total 18%)
- Anterior trunk: 18%
- Posterior trunk: 18%
- Each lower limb: 18% (total 36%)
- Perineum: 1%
- For children: Lund & Browder chart (head proportionately larger)
- MLI: >33% TBSA - poor prognosis; Parkland formula for fluid resuscitation
(GB) Complications of Burns:
- Hypovolemic shock (within 24-48 hrs) - loss of fluid and protein
- Acute oedema of glottis - from inhaled irritant smoke/hot gases
- Sepsis after 4-5 days - Pseudomonas, Staphylococcus, UTI
- Bronchopneumonia
- Gangrene, tetanus, anaemia
- Oesophageal stricture (chemical burns)
(GB) Joule Burns - Detailed:
- Central crater with peripherally raised margins; chalky white; floor pale
- Mild hyperaemia of adjacent intact skin
- Metallization: Deposition of metallic ions into skin (detected by Acro-Reaction test); only at Entry wounds
- Microscopic: Epidermal separation; palisading of nuclei; nuclear streaming; coagulative necrosis
- MLI: Presence of Joule burns NOT itself proof of electrocution (similar marks can occur post-mortem) EXCEPT for zone of hyperaemia
CHAPTER 2: ASPHYXIAL DEATHS
Q3 & Q15. DROWNING
Types of Drowning:
- Typical/Wet drowning (85-90%): Water aspirated into lungs; most common
- Dry drowning (10-15%): Laryngeal spasm; asphyxia without aspiration; lungs dry at autopsy
- Secondary/Delayed drowning: Symptoms appear hours after apparent recovery (surfactant damage)
- Immersion syndrome (Hydrocution): Sudden cardiac arrest/vagal inhibition due to cold water; no water aspirated; seen in alcoholics
- Salt water drowning: Hypertonic - draws fluid from blood → haemoconcentration; death faster (5-6 min)
- Fresh water drowning: Hypotonic - absorbed rapidly → haemodilution, haemolysis, VF; death in 3-4 min (faster)
Ante-mortem vs Post-mortem Drowning:
-
Froth: AM - Fine, white, lathery, copious, tenacious, REAPPEARS after wiping; PM - Absent or blood-stained, does NOT reappear
-
Hands: AM - Clenched (cadaveric spasm - vegetation/grass); PM - Relaxed, open
-
Lungs: AM - Voluminous, waterlogged, Emphysema aquosum; PM - Waterlogged but less emphysematous
-
Stomach: AM - Water/food in stomach; PM - No water in stomach
-
Diatoms: AM - In bone marrow, viscera (blood-borne); PM - Only in lungs/airways, not in viscera
-
Diatom Test: Diatoms in bone marrow = confirmatory of AM drowning
-
Gettler's Test: Fresh water: Left heart Cl⁻ < Right heart Cl⁻; Salt water: Left heart Cl⁻ > Right heart Cl⁻; Normal difference <10 mg% (>10 mg% significant)
ASPHYXIA
4 Stages of Pathophysiology:
- Stage of Dyspnoea (0-1 min): Increased RR; rise in BP and HR; cyanosis
- Stage of Convulsions (1-2 min): CO₂ acts on brain; convulsions/loss of consciousness; petechiae form; sphincters relax
- Stage of Exhaustion (2-3 min): Respiratory efforts decrease; BP falls
- Stage of Apnoea (3-5 min): Cessation of respiration; heart continues briefly; death
Classic PM Signs:
- Cyanosis
- Petechiae (Tardieu spots) - subconjunctival, facial, pleura, pericardium
- Congestion
- Fluidity of blood (dark, liquid)
- Right heart engorgement
- Pulmonary oedema
CHAPTER 3: POST-MORTEM CHANGES
(GB) Classification of PM Changes:
Immediate changes:
- Irreversible cessation of brain, respiration, circulation
- Facial pallor
- Changes in the eye
Early changes:
- Algor mortis
- Livor mortis (PM staining)
- Rigor mortis
- Primary flaccidity of muscles
- Loss of elasticity of skin
Late changes (Mnemonic: MAD):
- Mummification
- Adipocere
- Decomposition/Putrefaction
LIVOR MORTIS (GB)
Development:
- Onset: 30 minutes
- Well developed: 4 hours
- Completely develops: 6 hours
- Fixation: 8-12 hours
Colour by cause of death:
- Bluish-purple: Normal
- Cherry red: Carbon monoxide
- Bluish-green: Hydrogen sulphide
- Black: Opiates
- Brick red: Cyanide poisoning
Distribution by body position:
- Supine: Back of head, chest, legs (except pressure areas)
- Prone: Front of face, chest, abdomen
- Hanging: Lower forearms and legs (glove & stocking)
- Drowning in stagnant water: Face, upper chest
MLI:
- Sign of death
- Helps estimate TSD
- Determines position of body after death
- Determination of cause of death
- May be mistaken for bruise
RIGOR MORTIS
(GB) Exact Timing:
-
Starts: 1-2 hours after death
-
Takes 12 hours to develop (complete)
-
Persists for next 12 hours
-
Vanishes in next 12 hours
-
Total duration: approx 24-36 hours
-
Mechanism: ATP depletion → actin-myosin cross-bridges cannot break → muscles fixed in contracted state
-
Nysten's Law: Jaw → neck → trunk → upper limbs → lower limbs (cervicofrontal)
(GB) Conditions simulating Rigor Mortis:
- Heat stiffening
- Cold stiffening
- Cadaveric spasm
- Gas stiffening
PUTREFACTION
(GB) Sequence:
-
12-24 hrs: Greenish discolouration of right iliac fossa
-
36-48 hrs: Marbling AND skin slippage
-
48-72 hrs: Peeling of skin
-
72 hrs: Loosening of hair
-
Months: Skeletonisation
-
Casper's Dictum: 1 week in air = 2 weeks in water = 8 weeks in earth
-
Adipocere: Starts 3 days after death; takes 3-6 months to complete
-
Mummification: 3 months - 6 months after death
PMI ESTIMATION - Additional Biochemical Markers (GB)
Insect activity (Forensic Entomology):
- 18-36 hrs: Flies lay eggs
- 12-24 hrs: Eggs hatch into maggots/larvae
- 4-5 days: Maggots develop into pupae
- 8-12 days: Pupae into adult flies
- Lice die within 3-6 days after death
Changes in body fluids after death (GB):
- Blood: Potassium and magnesium RISE; sodium and chloride FALL
- CSF: Potassium, creatine, uric acid INCREASE; glucose DECREASES
- Vitreous humour: Potassium, magnesium, urea, creatinine INCREASE
Eye changes (GB):
- Eyeball: Flaccid due to fall in IOP (10 to 0 mmHg) within 4-6 hrs
- Tache noire: Dark brown-black deposit on sclera; triangular with apex toward canthus; within 3-6 hrs
- Cornea: Hazy and opaque at 6-8 hrs
Other circumstantial methods (GB):
- Stomach contents: Full with undigested food = death within 2-4 hrs of last meal
- Intestinal contents: Feces in pelvic colon suggests death at night; empty suggests death after morning evacuation
- Urinary bladder: Full bladder in morning = may have died before usual rising time
- Facial hair growth: Estimate survival time from time of last shave
CHAPTER 4: SEXUAL OFFENCES
Medicolegal Examination in Sexual Assault
Specimens to Collect:
- Vaginal swab (high/low) - spermatozoa, seminal fluid, DNA
- Cervical swab - sperm motility, acid phosphatase
- Anal swab (if anal assault); Oral swab (if oral assault)
- Blood - DNA, toxicology (DFSA drugs)
- Urine - toxicology (GHB, Rohypnol)
- Fingernail scrapings, pubic hair combing, clothing, bite mark swabs
Sperm survivability:
-
Motile: Up to 6-12 hours
-
Non-motile: Up to 72-120 hours (5 days)
-
Seminal stains: Weeks on fabric
-
Two-finger test: Medically unjustified; banned by Supreme Court - must NOT be performed
Reproductive Health - Additional from GB
Respired vs Unrespired Lungs:
- Volume: Large (liveborn) vs Small (stillborn)
- Colour: Mottled, salmon pink (liveborn) vs Uniformly bluish red (stillborn)
- Consistency: Soft, spongy (liveborn) vs Dense, firm (stillborn)
- Level of diaphragm: 6-7th rib (liveborn) vs 4-5th rib (stillborn)
- Hydrostatic test: Positive/float (liveborn) vs Negative/sink (stillborn)
- Fodere's test: 60-70 g (liveborn) vs 30-40 g (stillborn)
- Breslau's 2nd life test: Stomach floats (liveborn) vs Stomach sinks (stillborn)
Hydrostatic Test (Docimasia Pulmonum) - Limitations:
- False positive (sinks in stillborn): Putrefaction gas; artificial respiration
- False negative (float in liveborn): Neonatal atelectasis, premature, pneumonia, prolonged pressure
Multiparous vs Nulliparous Uterus (GB):
- Weight: 80-100 g (multiparous) vs 40-50 g (nulliparous)
- Body:Cervix ratio: 2:1 (multiparous) vs 1:1 (nulliparous)
- External os: Transverse patulous slit (multiparous) vs Circular, dimple-like (nulliparous)
- Uterine cavity: Rounded, spacious (multiparous) vs Triangular, smaller (nulliparous)
- Cervix: Cylindrical (multiparous) vs Conical (nulliparous)
CHAPTER 5: GENERAL TOXICOLOGY
Classification of Poisons (GB) - Mnemonic: CINCAM
- Corrosives: Strong acids (mineral: HCl, HNO₃, H₂SO₄; organic: oxalic, carbolic acid); Strong alkalis (NaOH, KOH, NH₄OH); Metallic salts
- Irritants: Inorganic (metallic: As, Pb, Hg, Cu; nonmetallic: phosphorus, iodine); Organic (plants: Abrus precatorius, castor; animals: snakes, scorpions); Mechanical (powdered glass, diamond dust)
- Neurotics: Cerebral (Somniferous - opium; Inebriants - alcohol; Deliriants - dhatura, cocaine, cannabis); Spinal (strychnine); Peripheral (curare)
- Cardiac: Digitalis, Oleander, Aconite, HCN
- Asphyxiants: CO, H₂S, CO₂
- Miscellaneous: Agrochemicals (OPC, AlPhos, Paraquat, Thallium); Drugs of dependence; Petroleum products; Food poisoning
Legal Duties of Doctor in Suspected Poisoning (GB)
- Inform police in ALL cases (government MO) - private practitioner must inform only in homicidal poisoning
- If doctor does not inform police - punishable under Sec. 176 IPC
- Note preliminary particulars of patient
- Take proper history (suicidal/homicidal/accidental)
- Inform senior doctor
- Collect evidence: gastric lavage, food, vomitus, blood, urine, faeces; preserve and send to FSL - Failure to preserve evidence: Punishable under Sec. 201 IPC
- Prepare MLC report with consent
- If patient about to die: arrange Dying Declaration
- If patient dies: Do NOT issue death certificate; send body for PM
- Opinion on nature of poison: Only after FSL report
Q2. ORGANOPHOSPHORUS POISONING
(GB) Classification of OPC:
- Alkyl phosphates: HETP, OMPA, TEPP, Malathion (Mnemonic: HOT MALA)
- Aryl Phosphates: Diazinon (Tik-20), Chlorthion, Parathion (Mnemonic: DCP)
Clinical Features - SLUDGE/DUMBELS:
- Muscarinic: Salivation, Lacrimation, Urination, Defecation, GI cramps, Emesis, Bradycardia, Bronchospasm, Miosis, Sweating
- Nicotinic: Muscle fasciculations, Weakness, Mydriasis, Tachycardia
- CNS: Anxiety, Depression, Restlessness, Seizures, Coma
(GB) Lab Diagnosis:
- AChE level in RBCs and plasma - decreased
- Symptoms occur when >50% of cholinesterase inhibited
- Liquid gas chromatography - to detect OPC in blood
- P-nitrophenol test - in case of parathion poisoning
Management:
- Remove from exposure; decontaminate (remove clothing, wash skin with soap and water)
- ABC stabilisation
- Atropine: 2-4 mg IV, repeat every 5 minutes until atropinisation (dry secretions, HR >80) - titrate to dry secretions, NOT pupil size
- Pralidoxime (PAM): 1-2 g IV over 15-30 min, then infusion; only within 24-48 hrs; relieves nicotinic features; contraindicated in carbamate poisoning (GB)
- (GB) Diacetyl monoxime (DAM) also used as AChE reactivator
- Benzodiazepines for seizures
- Avoid succinylcholine, morphine, barbiturates, phenothiazines
(GB) PM Findings:
- External: Smell of kerosene from nostrils and mouth; signs of asphyxia; blood-tinged froth
- Internal: GIT congested; lungs congested and oedematous; brain congested
(GB) MLI:
- Hospitalise all symptomatic patients for at least 4-6 days after resolution - risk of intermediate syndrome and respiratory depression
- OPC poisoning can imitate other toxidromes; misdiagnosis possible
- Accidental and occupational poisoning occurs in manufacturers, packers, sprayers, children
- Suicidal poisoning is common in India
Q16. ARSENIC POISONING
(GB) MOA:
- Arsenic affects cellular respiration by binding to PDH enzyme in mitochondria → inhibits oxidative phosphorylation → reduced cellular ATP → apoptosis
Clinical Features - ACUTE:
- GI: Metallic/garlic odour; nausea, vomiting (profuse, projectile, dark brown (GB)); rice water diarrhoea (like cholera); colicky abdominal pain; tenesmus
- Systemic: Dehydration, circulatory collapse; oliguria/anuria; haematuria; muscle cramps; haemolysis
- CVS (GB): Hypotension, ARDS, weak pulse, sunken eyes, arrhythmias
- Skin (GB): Delayed loss of hair, skin eruptions
Chronic Arsenic Poisoning:
- Mees' lines (Aldrich-Mees' lines) - white transverse lines on nails
- Arsenical keratosis (palmar/plantar)
- Rain-drop pigmentation
- Alopecia, golden hair (GB)
- Peripheral neuropathy - glove-stocking distribution
- Black foot disease: Vasospasm and thrombosis leading to gangrene (GB)
- Bone marrow depression, pancytopenia (GB)
(GB) Lab Investigations:
- Urine arsenic: >50 µg/L in 24 hrs urine = indicative; normal <50 µg/L; toxic >200 µg/L
- Blood arsenic: 0.9 µg/dL
- Hair arsenic: 75 µg%
- Nail arsenic: 100 µg%
- Tests: Reinsch test, Marsh test, Gutzeit test, AAS, NAA
Treatment:
- Gastric lavage with 1:5000 KMnO₄ (GB)
- BAL (Dimercaprol): Dose - 3 mg/kg IM 4-hourly for 2 days; then 6-hourly for 4 days; then 12-hourly (GB)
- Whole bowel irrigation (GB)
- Purgatives (GB)
- IV fluids, sodium bicarbonate to correct shock
- Hemodialysis if renal failure
- DMSA (succimer) - oral chelation; safer alternative
- D-Penicillamine - mild/chronic cases
(GB) PM Findings:
- External: Sunken eyeballs; rigor mortis appears early; delayed putrefaction; emaciated
- Internal: Ulceration of mouth/pharynx/oesophagus; stomach mucosa red velvety; lungs, liver congested; heart - subendocardial petechial haemorrhages
(GB) MLI:
- Homicide common: cheap, colourless, odourless, tasteless, easily obtainable; symptoms simulate cholera; gradual onset
- Suicide rare; accidental from well water or improper medicinal use
- Used on abortion sticks; may be used as cattle poison
CHAPTER 5B: ADDITIONAL POISONS (from Gautam Biswas)
CYANIDE (HCN) POISONING (GB)
MOA (in sequence):
- Cyanide inhibits cytochrome oxidase (Complex IV)
- Blocks final step of oxidative phosphorylation → prevents ATP formation
- Arrest in aerobic respiration → histotoxic hypoxia
- Blood saturated with O₂ but tissues cannot utilise it
- Conversion of pyruvate into lactate → lactic acidosis
Fatal Dose:
- HCN: 50-60 mg
- NaCN/KCN: 200-300 mg
Fatal Period:
- HCN: 2-10 minutes
- NaCN/KCN: 30 minutes
Signs and Symptoms:
- GIT: Burning taste, throat constriction, numbness, salivation, froth at mouth
- CNS: Headache, vertigo, dizziness, coma, anxiety
- CVS: Initially hypertension + reflex bradycardia; later hypotension + reflex tachycardia
- RS: Initially tachypnoea; later respiratory depression; smell of bitter almond in breath
- Eyes: Prominent; pupils dilated
Treatment:
- ABC; assisted ventilation, 100% O₂; cardiac monitoring
- Decontaminate: Remove from source; remove clothing; flush skin
- Gastric lavage: 5-10% sodium thiosulphate solution; followed by potassium carbonate (forms inert Prussian blue)
- Antidotal kit (3 steps): Step 1: Amyl nitrite pearl - inhale 30 secs every minute; Step 2: Sodium nitrite 300 mg IV slowly; Step 3: Sodium thiosulphate 12.5 g IV over 10-20 min
- Hydroxycobalamine (Vitamin B₁₂) IV - binds cyanide → cyanocobalamine
- Dicobalt EDTA
PM Findings:
- PM staining: BRIGHT RED (not cherry red like CO - important differentiator)
- Smell of bitter almonds on opening body cavity
- Oral/perioral erosions
- Lungs congested and oedematous
- Bitter almonds: Contain amygdalin (cyanogenic glycoside) → enzymatic hydrolysis in GIT → releases HCN
BARBITURATE POISONING (GB)
Clinical Features (Mnemonic: BAR = all functions reduced):
- CNS depression: Drowsiness, delirium, excitement, hallucinations, ataxia; coma with positive Babinski sign; loss of reflexes
- RS: Rapid/shallow or slow/laboured breathing (respiratory centre depressed)
- CVS: Decreased cardiac output → hypotensive shock, cyanosis, bradycardia
- GIT: Absence of bowel sounds in comatose (BAD prognosis)
- Renal: Scanty urine, contains albumin and sugar
- Skin: BARBITURATE BLISTERS (characteristic)
- Temperature: Decreased (hypothermia); fever if bronchopneumonia
Management:
- ABC
- Gastric lavage with 1:1000 KMnO₄ + activated charcoal
- Forced Alkaline Diuresis: Sodium bicarbonate in 5% dextrose IV
- Antibiotics to prevent bronchopneumonia
- Scandinavian method (combination of 1+2+3+4)
- Hemodialysis; Exchange transfusion
- Supportive care
SULPHURIC ACID POISONING (GB)
Signs and Symptoms:
- Oropharyngeal burns (blackening); pain in throat and epigastrium
- Violent cough, dyspnoea, glottic oedema
- Teeth become CHALKY WHITE (characteristic)
- Intense thirst, scanty urine; swollen lips and tongue
- Abdomen: Tender, distended; constipation and tenesmus
Complications:
- Neurogenic shock; Perforation of stomach; Peritonitis
- Septicaemia; Glottic oedema and asphyxia; Oesophageal stricture; Renal failure
Treatment:
- ABC; tracheostomy if glottic oedema
- Gastric lavage: CONTRAINDICATED
- Milk/water immediately to neutralise acid
- Avoid sodium bicarbonate (CO₂ production causes perforation risk)
- Steroids to prevent inflammation
- IV antibiotics if perforation
- Morphine for pain
METHYL ALCOHOL POISONING (GB)
Signs and Symptoms:
- GIT: Nausea, vomiting, cramps, alcohol odour, dehydration
- Eyes: Fixed and dilated pupils; photophobia; blurred/"snowfield vision"; scotoma; blindness due to optic neuritis/atrophy
- CNS: Headache, dizziness, restlessness, hypothermia, delirium, coma; convulsions (terminal)
- Renal: Acidosis, strongly acidic urine, scant urine
Treatment:
- Gastric lavage with sodium bicarbonate solution
- Sodium bicarbonate 4-hourly orally to treat acidosis
- Ethanol as competitive antagonist: 0.8-1 ml/kg orally of 95% ethanol OR 10 ml/kg IV of 10% ethanol in D5W
- Antidote: 4-methylpyrazole (Fomepizole) - competitive inhibitor of alcohol dehydrogenase; blocks formation of formaldehyde and formic acid
- Calcium folinate IV, thiamine, pyridoxine
- Cover eyes to protect from light
- Hemodialysis in severe poisoning
PHENOL (CARBOLIC ACID) POISONING (GB)
Signs and Symptoms:
- Eyes: Pupils constricted
- Skin: Cold and clammy; local: white painless eschar (damage to nerve endings → tingling → numbness)
- GIT: Burning, tingling then anaesthesia; diarrhoea; abdominal pain; vomiting RARE
- CNS depression: Headache, giddiness
- Kidneys: Renal failure
- CVS: Rapid, feeble, irregular pulse; coma
- Carboluria: Urine scanty, suppressed with GREENISH HUE (appears after 36-48 hrs of ingestion) - characteristic
PM Findings:
- External: Corrosion of mouth, tongue, chin; smell of phenol
- Internal: Brown leathery stomach (hardening of mucosa); haemorrhagic nephritis
Management:
- ABC
- Gastric lavage with water + charcoal + OLIVE OIL (only corrosive acid where gastric lavage is indicated)
- Normal saline with sodium bicarbonate IV
- Hemodialysis if renal failure
General Principles of Treatment in Poisoning (GB)
Removal of Unabsorbed Poison:
- Injected: Remove sting (bee/wasp); tourniquet/ice; treat anaphylaxis
- Contact: Remove clothes; wash with soap and water
- Inhaled: Remove to fresh air; O₂ supplementation
- Ingested: Gastric lavage (Ewald tube or Boas tube)
Methods for Removal of Absorbed Poison (GB):
- Forced alkaline diuresis: Sodium bicarbonate - for acidic drugs (salicylate, barbiturate)
- Forced acid diuresis: Ammonium chloride - for alkaline drugs (amphetamines, quinine, TCA)
- Haemodialysis (Mnemonic LABS): Lithium, Alcohol, Barbiturates, Salicylates
- Haemoperfusion: Blood through activated charcoal filter - for caffeine, barbiturates, mushroom
- Whole bowel irrigation
- Diaphoretics
Contraindications to Gastric Lavage:
- Corrosive poisoning (acids, alkalis) - risk of perforation
- Petroleum products/hydrocarbons - risk of aspiration
- Convulsions (unless airway protected with ETT)
- Loss of consciousness (unless airway protected)
- Strychnine poisoning
-
4-6 hrs after ingestion
- Oesophageal pathology (stricture, varices)
CHAPTER 6: GASEOUS POISONS
H₂S POISONING
Mechanism: Inhibits cytochrome c oxidase (same as cyanide)
PM Findings:
- Cyanosis; greenish/black discolouration of viscera (H₂S + Hb → sulphmethaemoglobin)
- Pulmonary oedema; frothy fluid in airways; petechiae
- Smell of rotten eggs on opening body; faster putrefaction
CHAPTER 7: SNAKE BITE
Poisonous vs Non-Poisonous Snake
- Fangs: Poisonous: 1-2 large hollow/grooved fangs; Non-poisonous: Multiple small solid teeth; no fangs
- Bite mark: Poisonous: 1-2 fang marks + teeth marks; Non-poisonous: Horseshoe pattern, no fang marks
- Head: Poisonous: Triangular (vipers), oval (elapids); Non-poisonous: Usually oval/round
- Subcaudal scales: Poisonous: Single row; Non-poisonous: Double row
Clinical Features - KRAIT (Bungarus caeruleus)
- Venom: Neurotoxic (alpha/beta-bungarotoxin)
- Bites at night; minimal local signs
- Descending paralysis: Ptosis, diplopia, dysphagia, dysarthria → respiratory failure
- NO coagulopathy
- (GB) Mnemonic: 5Ds + 2Ps - Dyspnea, Dysphonia, Dysarthria, Diplopia, Dysphagia + Ptosis, Paralysis
Clinical Features - VIPER (Russell's Viper)
- Venom: Vasculotoxic + Cytotoxic
- Local: Severe pain, massive swelling, blistering, skin necrosis, haemorrhagic bullae
- (GB) "Bilateral parotid swelling" - 'viper head'
- Systemic: DIC; Bilateral Renal Cortical Necrosis (BRCN - Russell's viper specific)
20 WBCT - Procedure (GB)
- Place a few ml of venous blood in clean, dry glass tube
- Leave undisturbed 20 min at room temperature
- Tip the tube once
- Blood still unclotted and runs out = incoagulable blood = viperine envenomation
- Normal 20 WBCT excludes viperidae species
Management
First Aid Do's:
- Immobilise limb
- Remove rings/jewellery
- Pressure immobilisation (for elapid bites only)
- Wash bite with soap and water (GB)
- Cover with clean dry dressing (GB)
Don'ts:
- Do NOT incise and suck
- Do NOT tourniquet
- Do NOT electric shocks
- Do NOT ice
- Do NOT drink alcohol as painkiller (GB)
- Do NOT take aspirin/ibuprofen (GB)
(GB) ASV Dose:
- 80-100 mL serum diluted in 200-500 mL isotonic saline
- Recommended initial dose 8-10 vials slow IV over 1 hour
(GB) Supportive - Vasculotoxic:
- Fluid resuscitation with NS, Ringer's, FFP; Dopamine for hypotension
- Fresh blood/FFP/platelets for coagulopathy; Haemodialysis for ARF
- Surgical excision for gangrene prevention
CHAPTER 8: INORGANIC POISONS
ALUMINIUM PHOSPHIDE (ALP) POISONING
Signs and Symptoms:
- Garlic/phosphine odour (DISTINCTIVE)
- GI: Nausea, vomiting, abdominal pain; burning in mouth/throat/stomach
- CVS: Hypotension, bradycardia, arrhythmias (MAIN CAUSE OF DEATH), toxic myocarditis
- Pulmonary oedema (frothy blood-stained sputum), ARDS
- CNS: Restlessness, seizures, coma
- Metabolic acidosis, lactic acidosis
(GB) Treatment - Detailed:
- Inhalation: Remove from source to open area
- ABC
- Gastric lavage with 1:10000 KMnO₄ + activated charcoal; Antacids and liquid paraffin
- IV fluids for hydration and renal perfusion; Dialysis if renal failure
- Treatment of shock: IV fluids, Hydrocortisone, Low-dose dopamine, ECMO (GB)
- Treatment of metabolic acidosis: IV NaHCO₃; if fails → haemodialysis
- Treatment of arrhythmias: IV MgSO₄ for hypomagnesaemia and arrhythmias (GB)
- Antiarrhythmic agents
- No specific antidote - Avoid oils (increase absorption)
Samples:
- Gastric content in airtight container (phosphine is volatile)
- Blood, urine, liver, kidney, lung
- Transport in ice; container must be airtight
CHAPTER 9: VEGETABLE POISONS
DATURA POISONING
- Active Principles: Hyoscine (Scopolamine), Hyoscyamine, Atropine (Belladonna alkaloids)
- Fatal dose: 80-120 seeds (100 seeds approx)
- (GB) Stupefying dose: 40-60 seeds
(GB) 10 Ds of Datura:
- Dryness of mouth
- Dysphagia - difficulty swallowing
- Dysarthria - difficulty talking
- Dilatation of cutaneous blood vessels (flushing)
- Dry hot skin (hyperthermia/fever)
- Drunken gait
- Diplopia (due to mydriasis)
- Drowsiness
- Delirium, hallucinations, pill-rolling movements, pulls imaginary threads from clothes
- Dysuria due to urinary retention
(GB) Diagnosis Tests:
- Mydriatic test: Drop of suspected specimen in rabbit's eye → dilation of pupils
- Pilocarpine test: Instil 2-3 drops of 1% pilocarpine in patient's eye - if NO constriction → Datura poisoning
- Atropine detected by Radioimmunoassay
Treatment:
- ABC; Gastric lavage with KMnO₄ or tannic acid (GB); Activated charcoal
- Physostigmine 0.5-2 mg slow IV; dose (GB): 0.5-1 mg slow IV over 5 min with ECG monitoring; repeat 20 min if needed
- Purgatives and colonic lavage (GB)
- Short-acting barbiturates for delirium (GB)
- IV Diazepam for seizures; Cold sponging/tepid sponging for hyperthermia
- Dark quiet room; Catheterisation for urinary retention
(GB) MLI - Additional:
- "Rail-road poison" - used by criminals as stupefying agent for robbery, rape
- Resists putrefaction
- Used as adulterant in country liquor to enhance kick effect
- Used in Chinese herbal medicines to treat asthma
(GB) PM Findings:
- External: Signs of asphyxia
- Internal: GIT - inflamed mucosa containing seeds and fragments; Lungs, brain, other viscera - oedematous and congested
CHAPTER 10: NARCOTIC POISONS
OPIUM POISONING
- Toxic triad: Coma + Miosis + Respiratory depression
(GB) 3 Stages of Opium Poisoning (Mnemonic: ESpN):
- Stage of Excitement: Euphoria, well-being, freedom from anxiety, talkativeness, laughter, hallucinations, flushed face, red eyes, rapid HR
- Stage of Stupor: Headache, nausea, vomiting, weakness, heaviness, drowsiness, contracted pupils, cyanosed face/lips
- Stage of Narcosis/Coma: Deep coma; muscles flaccid; absent reflexes; congested conjunctiva; secretions suspended except perspiration; pin-point non-reacting pupils; hypotension; hypothermia; weak pulse; slow stertorous respiration
Differential Diagnosis:
- Pupils: Opium - Pin-point; OPC - Pin-point; Barbiturate - Dilated; Alcohol - Dilated; Pontine Haemorrhage - Pin-point
- Secretions: Opium - Dry; OPC - Profuse; Barbiturate - Dry
- Odour: Opium - Opium smell; OPC - Garlic/petrol; Barbiturate - Nil; Alcohol - Alcohol
- Response to naloxone: Opium - Dramatic reversal; OPC/Barbiturate/Alcohol - No
- Antidote: Opium - Naloxone; OPC - Atropine+PAM; Barbiturate - Flumazenil
(GB) Management - Detailed:
- ABC - airway critical
- Stomach wash with 1:5000 KMnO₄
- Activated charcoal - method of choice for decontamination
- Enema with 30 g sodium sulphate twice daily (GB)
- Whole bowel irrigation in body packers (GB)
- Naloxone: 0.4-2 mg IV/IM; repeat every 2-3 min; max 10 mg; short half-life (30-90 min) - may need infusion
SHORT NOTES - ENHANCED
FORENSIC PSYCHIATRY & MENTAL HEALTH
McNaghten's Rules / IPC Sec 84:
- (GB) History: In 1843, Daniel McNaughton shot Mr. Edward Drummond (PM Peel's secretary) believing persecution by Tory Party; suffered paranoid delusions; acquitted on insanity ground
- Rules: At time of act, due to disease of mind, person: (1) did NOT know nature and quality of the act, OR (2) did NOT know it was wrong
- IPC Sec 84: "Nothing is an offence which is done by a person who, at the time of doing it, by reason of unsoundness of mind, is incapable of knowing the nature of the act or what he is doing is either wrong or contrary to law"
(GB) Civil Responsibility of Insane:
- Contracts: Invalid if made during mental illness; valid if made during lucid interval
- Marriage: Invalid if either party suffered mental illness at time of ceremony
- Witness: Not competent to give evidence; competent during lucid interval
- Testamentary capacity: Will invalid; valid if made during lucid interval
- Guardianship: Cannot be legal guardian of minor
- Consent: Not valid
- Adoption: Not allowed if either parent mentally ill
Criminal Responsibility of Insane:
- Legal test of insanity = "Right or Wrong" test
- Requirements: Evidence of mental disease; must exist at time of crime; degree must prevent understanding act is wrong
(GB) Delusions - Types:
- Hypochondriacal: Believes having serious disease based on own interpretation
- Othello syndrome: Believes partner is unfaithful; seen in alcohol dependence
- Delusion of Reference: Everyone is looking at or talking about him
- Nihilistic: Denies existence of own body/mind/world; seen in depression
- Delusion of Influence: Thoughts/feelings controlled by outside agency
- Erotomania (Delusion of Love): Believes person of higher status is in love with them; common in females
- Persecutory: MOST COMMON; people are trying to kill/harm him
(GB) ICD-10 Classification of Mental Illness:
- Organic mental disorders: Delirium, dementia
- Psychoactive substance use disorders: Acute intoxication, withdrawal
- Schizophrenia and delusional disorders
- Mood disorders: Manic, depressive, bipolar
- Neurotic and somatoform disorders: Anxiety, phobia, OCD
- Adult personality disorders; Mental retardation; Developmental disorders
Hallucination Types:
- Auditory: False perception of sound; MOST COMMON; seen in Schizophrenia
- Visual: Observes something without it being present; seen in Delirium tremens
- Olfactory: False sense of smell; seen in Temporal lobe disorders, schizophrenia
- Gustatory: Different tastes without food/drink; seen in Temporal lobe epilepsy
- Tactile: Crawling of insects/rats on body; seen in Cocainism, schizophrenia
(GB) Illusion:
- False interpretation of external object which HAS real existence (vs hallucination - no external stimulus)
- Types: Universal (same for all, e.g., rail tracks appearing to converge) and Personal (differ per individual)
- Sane person can correct illusions; insane continues to believe even when real facts pointed out
(GB) Doctrine of Diminished Responsibility:
- UK defence to murder; reduces to manslaughter (culpable homicide) if established
- Requires: Abnormality of mental functioning; from recognised medical condition; substantially impaired ability to understand conduct/form rational judgment/exercise self-control; provides explanation for killing
(GB) Lucid Interval:
- Insanity: Period between two episodes of mental illness where all signs disappear; seen in Bipolar disorders; person responsible for civil/criminal acts during this period
- Head Injury: Period of consciousness between two phases of unconsciousness; seen in EDH; if doctor discharges patient in lucid interval without proper examination and patient dies → negligence
(GB) Impulse and Impulsive Disorders:
- Kleptomania: Irresistible desire to steal articles of low value
- Pyromania: Impulse to set things on fire
- Oniomania: Impulse of shopping
- Dipsomania: Excessive desire to drink alcohol
- Mutilomania: Desire to maim animals
(GB) Phobia:
- Definition: Morbid and irrational fear in presence of stimulus; person tries to avoid situation
- Agoraphobia: Morbid fear of places from which escape is difficult (crowd, market)
- Social phobia: Fear of socially demanding situations (stage fear, public speaking)
- Specific/Simple phobia: MOST COMMON; e.g., claustrophobia, hydrophobia, zoophobia
(GB) Mental Healthcare Act 2017:
- Person can make advance directive for treatment/care
- Decriminalized attempt to commit suicide
- Rights: Right to access mental healthcare; right to information; right to dignity; right to confidentiality
- Child <3 years of woman receiving treatment should NOT be separated from her
- Supported admission: Minor (age <18 yrs) - any such admission must be informed to board within 72 hrs
- Independent admission: Person ≥18 yrs
- Treatments PROHIBITED: Direct ECT without muscle relaxants/anaesthesia; ECT for minors without board permission; psychosurgery without permission; sterilization as treatment for mental illness
MEDICAL JURISPRUDENCE - ENHANCED
Professional Negligence:
- Definition: Lack of reasonable care and skills on part of doctor that resulted in injury/death
- (GB) Components (4D's): (1) Duty of doctor; (2) Dereliction of duty; (3) Damage to patient; (4) Direct causation
Civil vs Criminal Negligence:
- Trial: Civil court/consumer court vs Criminal court
- Negligence: Simple absence of care vs GROSS negligence
- Punishment: Monetary compensation vs Imprisonment, fine or both
- Evidence: Strong evidence sufficient vs Beyond reasonable doubt
- Complainant: Sufferer party vs Public prosecutor (State vs doctor)
- Contributory negligence: Defence for doctor vs NOT a defence
(GB) Defences Against Negligence:
- No duty owed to patient
- Res judicata: Matter already decided by court; cannot be tried again
- Contributory negligence: Patient also found negligent
- Therapeutic misadventure: Damage from drug/procedure (hypersensitivity to penicillin); doctor not liable
- Limitation: Case must be filed within 2 years from date of alleged negligence
- Error of judgement: Doctor's wrong decision - not liable for negligence
- Products liability: Defective drug/instrument from manufacturer - manufacturer held responsible
- Informed consent for the act
(GB) Penal Erasure:
- Temporary: Doctor not allowed to practise for specified period
- Permanent ("Professional Death Sentence"): Permanent removal; doctor cannot practise for whole life
- Given for: Adultery, addiction to drugs, alcoholism, criminal abortion, female feticide
- Appeal: To Central Health Ministry within 30 days → forwarded to NMC
(GB) Consumer Protection Act:
- 1986: CPA introduced; 1992: Medical services covered; 2019: New Act replaced 1986 Act
- E-filing of complaints; Mediation provisions
- No lawyer required; No court fee; Fast-track courts
- Limitation: 2 years from date of cause of action
(GB) Consumer Disputes Redressal:
- District Commission: District level; headed by District Judge; jurisdiction up to ₹1 crore
- State Commission: State level; headed by High Court Judge; jurisdiction ₹1 crore to 10 crores
- National Commission: National level; headed by Supreme Court Judge; jurisdiction >₹10 crores
(GB) Dying Declaration vs Dying Deposition:
- Oath: Not required (DD) vs Must (deposition)
- Recorded by: Anyone - magistrate/doctor/police (DD) vs Only magistrate (deposition)
- Accused party: Not allowed (DD) vs Allowed (deposition)
- Cross-examination: Not allowed (DD) vs Allowed (deposition)
- Followed in India: YES (DD) vs NO (deposition)
- If person survives: Loses value; corroborative only (DD) vs Value retained (deposition)
- Legal value: Less (DD) vs More (deposition)
- Type of evidence: Documentary (DD) vs Oral (deposition)
(GB) Expert Witness:
- Defined under Sec. 45 IEA
- Can draw conclusions on facts observed by himself or others
- Can express opinion on observations made by others
- Can volunteer information; highly responsible for comments
(GB) Leading Questions:
- Definition: Any question suggesting the answer the person putting it wishes to receive; answered Yes/No
- NOT allowed in Examination-in-Chief and Re-examination
- Allowed in cross-examination
- Allowed in examination-in-chief ONLY if: (1) witness declared hostile by court; (2) court gives permission
(GB) Conduct Money:
- Fee paid to witness in CIVIL cases at time of serving summons to meet expenses
- In criminal cases: No conduct money; witness must attend in interest of State; Government pays TA/DA
(GB) Magistrate Powers:
- Chief Judicial Magistrate: Imprisonment up to 7 years; Unlimited fine
- Judicial 1st Class Magistrate: Imprisonment up to 3 years; Fine ₹10,000
- Judicial 2nd Class Magistrate: Imprisonment up to 1 year; Fine ₹5,000
(GB) Novus Actus Interveniens:
- "New intervening act" - independent event after accused's act that caused/contributed to consequence
- Breaks causal chain between accused's action and liability
- Defence for accused to prove liability is limited/non-existent
(GB) Section 53 CrPC:
- Examination of accused by medical practitioner at request of police officer (not below rank of sub-inspector)
- Includes: Blood, bloodstains, semen, swabs, sputum, sweat, hair, fingernail clippings, DNA profiling
- Female accused: Examined only by or under supervision of female doctor
IDENTIFICATION - ENHANCED
Fingerprint Patterns:
- Loops (65-70%): Ulnar loop; Radial loop
- Whorls (30-35%): Concentric circles; require 2 triradii
- Arches (5% - LEAST COMMON): Plain arch (no triradius); Tented arch (one triradius)
Superimposition:
- Used when only skull available; face destroyed; mass disaster
- Dacosta's method, Glaister's method (radiographic), video superimposition (most common modern method)
TOXICOLOGY SHORT NOTES - ENHANCED
- Burtonian Line: Blue-black line at gingival margin; pathognomonic of chronic lead poisoning; formed by Lead + H₂S → Lead sulphide
Plumbism (Chronic Lead Poisoning):
- Burton's line; Basophilic stippling of RBCs; Microcytic anaemia
- Peripheral neuropathy: WRIST DROP (radial nerve palsy), foot drop
- Encephalopathy (children); Lead colic; Lead lines on X-ray of long bones
- Treatment: CaNa₂EDTA, DMSA (succimer), BAL
Botulism:
- Toxin: Clostridium botulinum (Type A most lethal)
- Mechanism: Botulinum toxin cleaves SNARE proteins → blocks ACh release at NMJ → descending flaccid paralysis
- Features: Descending paralysis starting with cranial nerves (diplopia, dysphagia, dysarthria) → limbs → respiratory; NO fever, NO sensory loss; constipation
- vs Guillain-Barré: No sensory deficit in botulism; DESCENDING vs ascending
- Treatment: Botulinum antitoxin (trivalent ABE); ventilation
Cannabis Preparations:
- Bhang: Dried leaves/stems in water; Least potent; legal in some states
- Ganja: Dried flowering tops of female plant; smoked; Moderate potency
- Charas/Hashish: Resin scraped from plant; Most potent
- Hash oil: Extracted; Extremely potent
- Active principle: THC (Δ⁹-Tetrahydrocannabinol)
Strychnine vs Tetanus:
- Cause: Strychnos nux-vomica alkaloid (Strychnine) vs C. tetani exotoxin (tetanospasmin)
- Onset: Rapid 15-30 min (Strychnine) vs Incubation 3-21 days (Tetanus)
- Consciousness: PRESERVED in both (key differentiator for strychnine)
- Spasm trigger: Sudden stimulus, open mouth (Strychnine) vs Any sensory stimulus (Tetanus)
- Fever: Absent early (Strychnine) vs Often present (Tetanus)
- Treatment: Diazepam, muscle relaxants, GA (Strychnine) vs Antitoxin + penicillin + diazepam (Tetanus)
Coma Cocktail Therapy:
- Thiamine 100 mg IV - BEFORE glucose (to prevent Wernicke's in alcoholics)
- Dextrose 50% - 50 ml IV (hypoglycaemia)
- Naloxone 0.4-2 mg IV - opioid overdose
- Flumazenil 0.2 mg IV - benzodiazepine overdose (cautiously - may precipitate seizures)
- O₂ - all unconscious patients
Poison Signs/Symptoms Quick Reference (GB):
- Miosis: Opioids, phenol, OPC, carbamates, ethanol, nicotine, barbiturates, BZDs
- Mydriasis: Dhatura, atropine, cannabis, strychnine, HCN, anticholinergics, amphetamine, cocaine, methanol
- Cherry red PM staining: Carbon monoxide
- Bright red PM staining: Cyanide
- Bluish-green PM staining: H₂S
- Garlic odour: Arsenic, AlP (phosphine), OPC (kerosene smell)
- Bitter almond odour: Cyanide
- Snowfield vision: Methanol
- Carboluria (green urine): Phenol
- Barbiturate blisters: Barbiturate poisoning
- Chalky white teeth: Sulphuric acid
- Rice water diarrhoea: Arsenic, cholera
- Hyperpyrexia: Amphetamines, atropine, cocaine, salicylates, strychnine, dhatura
- Seizures: Amphetamines, antidepressants, cocaine, alcohol withdrawal
FORENSIC PATHOLOGY & AUTOPSY
Methods of Organ Removal at PM:
- Virchow's method: Each organ removed separately
- Ghon's method (en bloc): Organs removed in blocks
- Letulle's method (en masse): All organs removed as single mass, then separated
- Rokitansky's method: Organs removed in situ, examined on their beds
Preservation of Viscera:
- Use saturated SALT SOLUTION (NOT formalin or spirit - destroys volatile poisons/drugs)
- Include: Stomach + contents; Small intestine; Liver (500 g); Kidney; Urine; Blood (100 ml); Vitreous humour; Brain (500 g); Bone marrow (chronic metal poisoning)
Virtual Autopsy:
- Non-invasive PM using CT/MRI
- Preserves body integrity; permanent digital record; 3D reconstruction; detects gas emboli
- But cannot replace standard autopsy
Negative Autopsy:
-
No anatomical cause found
-
Occurs in: arrhythmia, vagal inhibition, drug/toxin death, electrocution, anaphylaxis, dry drowning
-
Cafe Coronary: Sudden death from choking on food (meat bolus) while eating; mimics MI; Heimlich manoeuvre
-
Burking: Simultaneous compression of chest + mouth/nose closure; named after William Burke (1828); no external signs of violence; signs of asphyxia only
Battered Baby Syndrome:
- Multiple injuries at different healing stages in child <3 years
- Typical: Posterior rib fractures; metaphyseal fractures (corner/bucket handle); skull fractures; subdural haematoma (shaken baby); retinal haemorrhages; bruises in unusual sites
- SDH is MOST CONSISTENT feature (GB)
KEY DIFFERENTIATIONS (GB)
Psychosis vs Neurosis:
- Insight: Absent (Psychosis) vs Present (Neurosis)
- Delusions/hallucinations: Present (Psychosis) vs Absent (Neurosis)
- Dealing with reality: Impaired (Psychosis) vs Preserved (Neurosis)
- Examples: Schizophrenia (Psychosis) vs Anxiety, phobia (Neurosis)
True Virgin vs False Virgin:
- True Virgin: Never had intercourse; intact hymen; admits only tip of little finger; small clitoris; narrow vagina with marked rugosity
- False Virgin: Had intercourse but hymen intact; easily admits two fingers; enlarged clitoris; roomy vagina with less rugosity
Natural vs Criminal Abortion:
- Marks of violence: Absent (Natural) vs Present (Criminal)
- Foreign body: Absent (Natural) vs May be present (Criminal)
- Toxic effects: Absent (Natural) vs May be present (Criminal)
- MLC: Not required (Natural) vs Mandatory (Criminal)
KEY LEGAL SECTIONS (Quick Reference)
- IPC 44: Definition of Injury - "any harm, whatever illegally, caused to any person in Mind, Reputation, Body or Property" (GB)
- IPC 84: Act of unsound mind (insanity defence)
- IPC 176: Doctor not informing police in poisoning case - punishable
- IPC 193: Perjury - false evidence under oath
- IPC 201: Destruction of evidence (failure to preserve)
- IPC 299/300: Culpable homicide/Murder
- IPC 304-A: Criminal negligence - 2 years imprisonment + fine
- IPC 312-316: Abortion/MTP offences
- IPC 319: Hurt - "any bodily pain, disease or infirmity caused to any person" (GB)
- IPC 320: Grievous hurt (8 types)
- IPC 326A: Acid attack - minimum 10 years
- IPC 328: Administering poison with intent
- IPC 375/376: Rape and punishment (minimum 7 years)
- IPC 377: Unnatural offences
- Sec. 45 IEA: Expert witness (GB)
- Sec. 53 CrPC: Examination of accused by doctor (GB)
- Sec. 174 CrPC/BNSS: Police inquest
- Sec. 176 CrPC/BNSS: Magistrate's inquest
- MTP Act 1971 (2021): Up to 20 wks (1 RMP); up to 24 wks for special categories (2 RMPs); beyond 24 wks - State Medical Board
- NDPS Act 1985: Narcotic drugs control
- POCSO Act 2012: Protection of children from sexual offences
- TOH Act 1994: Transplantation of human organs (brain death)
- Consumer Protection Act 2019: Medical services covered; limitation 2 years (GB)
- Mental Healthcare Act 2017: Rights of mentally ill; decriminalised suicide attempt (GB)
References: KS Narayan Reddy - The Essentials of Forensic Medicine & Toxicology (36th Ed., 2026) | Gautam Biswas & Tejpreet Singh - Exam Preparatory Manual of Forensic Medicine and Toxicology | Parikh's Textbook of Medical Jurisprudence | PC Dikshit - Textbook of Forensic Medicine & Toxicology
(GB) = Points added from Gautam Biswas