Forensic Medicine & Toxicology (Points to Remember)

Forensic medicine: is the application of medical and paramedical knowledge in the administration of law and justice.

Legal medicine and state medicine are other names for it.

Medical jurisprudence: Deals with the legal rights, privileges, duties and obligations of medical practitioner.

Pin – point pupils = Opium

Dilatation of pupils = Dhatura, Cyanide

Constriction of pupils = Opium, phenol, organo-phosphorus, physostigmine, chloral hydrate.

Cumulative poisons are: Barbiturates, and methyl alcohol

Habit forming poisons are: Caffeine and Nicotine.

 Addiction drugs are: Alcohol, Barbiturates, Coccaine, Cannabis, Chloral hydrate, Opium, Pethidine.

Hemodialysis is good value in: Salicylate, methanol, barbiturate, and aspirin (except kerosene oil and diazephem)

 1st sign of intra-uterine death: Gas shadow in aorta (as early as 12 hours).

Increased anion gap is seen in Salicylate poisoning, lactic acidosis, starvation.

 Ideal suicide poison = Cyanide

Ideal homicide poison = Thallium, fluoride compounds.

Commonly used homicidal poisons: Arsenic, aconite

Commonly used suicidal poisons: Endrine, Opium, Barbiturates, Organophosphorus  compounds.

 Poison resembling cholera = Arsenic

 Poison resembling tetanus = Strychnine

 Poison resembling natural death = Thallium

Poison resembling fading measles = Arsenic

 Poison resembling thyrotoxicosis = Bi-nitro compounds.

 

Tests for detecting poisons:

Arsenic = Marsh’s test, Reinsch’s test
Opium = Marquis test
Alcohol = Mc’evan’s test
Datura = Mydriatic test
Phenol = Green urine.

The Percentage of blood alcohol in the stage of “dead drunk” is 0.5%. 

Pisiform gets ossified by 12 yrs of age.

By 14 yrs. patella gets ossified.

 Anterior fontanelle closes by 18 months of age.
The height of a child is double of birth height by 4 years of age,
Under IPC, a person below 7 years is not criminally responsible.
 Fatal period of Datura poisoning is 24 hours.
 In India, rigor mortis sets within 1-2 hours.
 While dispatching blood and urine for chemical analysis, sodium fluoride is added  as preservative in concentration of 50 mg/10ml.

Critical level of alcohol in blood is 0.15%.
The minimum age for giving consent for surgery is 18 years.
 In fractured ends of bone, soft provisional callus is formed by 15 hours.
 The minimum time required for adipocere formation in a dead body is 21 days.
 Indian Medical Council Act was enacted in 1956.
 Mental retardation is I.Q. Below 70.
 Ratio between ethyl alcohol in blood to urine is 1:1.33
 Gas rigidity appears after 72 hours.
  Marbling is noticed by 36 hours.
  Full development of rigor mortis takes about 12 hours.

  In exhumation, 6-7 samples of earth are collected.
  Intercourse with wife below 15 years of age is considerable rape.
  Fatal period of aconite isusually 1-5 hours.
  Cooling of body is gradual upto 1-3 hours.
  Hypostasis is mottled within first 3 hours of death.
  Killing range of a militry rifle is 3000 yards.
  Juvenile offender is a person under 16 years
  The dispersion of pellets is seen usually at distance beyond 10 feet.
  In a gunshot wound, the presence of singeing of hair or charring of skin denotes a fire up to 18 inches.
  Dispersion of pellets in shotgun injury is calculated as dispersion in inches = 1.5  times the dispersion in yards.
  An infant born before 210 days is not legally considered capable of maintaining a separate existence.
  A bruise showing bluish black discolouration is 4 days old.
 The upper limit of safety for carbon monoxide in air is 0.01%.

 Rh positivity in India is 93%.
 In an abrasion, the scab usually dries and falls between 4-6 days.
 Fatal dose of opium is 2 gm.
 The range of an air rifle is about 90 yards.
  Mixed dentition is seen in children between 6-12 years of age.
  Basisphenoid unites the basi-occiput at the age to 22 years.
  First permanent molar appears at age of 6-7 years.
  Judicial first class Magistrate can pass a sentence of imprisonment upto 3 years.
  Age of maturity for those under court of wards is 21 years.

 In India, sexual maturity is gained at 14 years of age. 

The degree of accuracy in determining sex from long bones is 80%.
 Fatal period of sulphuric acid poisoning is 18-24 hours.
 Multiplying factors for estimating stature from humerus and femur in males are 5- 5.3 and 3.6-3.8 respectively.
 Colliquative liquefaction is seen within 1 week after death.
 A contusion assumes green colour by 6 days.
 Marriage age for boys and girls are 21 years and 18 years respectively.
 Internal organs take 24 hours to cool. A person becomes major at the age of 18 years.

Eruption of temporary teeth is completed by 2 to 2.5 years. 

Foetal parts can be detected on plain X-ray usually by 16 weeks.

 Child below 12 years is not required to take an oath.
 Xiphoid process unites with sternum at age of 40 years.
 Cranial capacity is 10% less in females.
 Nuclear features persist in decomposition for a period of 2-3 years.
 Precipitin test is positive to be opium in dead body upto 10 years.
 After death, benzidine test is positive upto 150 years. Bones begin to decompose after death in 3-10 years.
 Less than 7 aminoacids in bone suggest age of bone after death as more than 100  years.

The rate of cooling of body in first 6 hours is 2.5°F and in next 6 hours as 1.5″-2.0 F.

Victim of drowning in a state of suspended animation can be revived as long as 10-20 minutes. 

Centre of ossification for pisiform bone appears at an age of 10-12 years.
The floatation time in summer for a dead body after drowning is one day.
 The age of 15 years old female is best determined by the radiography of upper end of radius and ulna.

 Maggots in a dead body do not appear before 48 hours.
 Hairs become loose after 72 hours of death.
 Epiphyseal union of sternal end of clavicle occurs at age of 22 years.
 Washer woman’s hands and feet usually occur within 12-18 hours.
 Saponification in drowning occurs in about 5 weeks.
 Death ensues in about 5 mts. of complete submersion.
  By ABO.RH, MN systems the exclusion of Paternity is about 50%.
  Estimation of Age from eruption of teeth is possible upto 17 to 21 years of age.

  Gustafson’s method for estimation age of adult over 21 years.
  In poisoning by salicylates, the Gastric lavage is useful upto 24 hours.
  The age of consent for medical examination in cases of rape is minimum 12 years.
   If a person is absent from his usual haunts, and has not been heard for 7 hears, he is presumed to be dead.
 Infanticide means unlawful destruction of child below 1 year of age.
 By ABO, Rh, MN systems the exclusion of Paternity is about 50%
 Estimation of Age from eruption of teeth is possible upto 17 to 21 years of age
 In poisoning by salicylates, the Gastric lavage is useful upto 24 hours
 The age of consent for medical examination in cases of rape is minimum 12 years
 In sin of Gomorrah-buccal swabs are useful upto 9 hours
 In most countries, breath alcohol concentration 35 mg/100 ml is considered an  offence After absorption, the ratio of alcohol  in blood and urine is constant and is  1:1.31

 Histologically, reticulum fibres in an abrasion are seen on 8 days
 Widmark’s formula for urine analysis of alcohol is 3/4 prq
 Pancreas constitute 0.1% of body weight
 Punishment for false evidence is given under section 193 of IPC
 Length of a female larynx is about 3.8 cm
 Calcification of third molar begins at 8-10 years.
 Lip prints on cheiloscopy are divided into 8 patterns

The diameter of “human hair at 15 years of age is 0.053 ram *

Alcohol gaze nystagmus is produced at an average blood levels of 80 mg%
The residual alcohol in mouth takes about 20 min to disappear and within this  period breath analyser test may be false   positive
Skeletal muscles constitute about 29% of body weight
 Term ‘under the influence’ of alcohol is used when blood concentration is 80- 100mg%
  Statutory rape is rape under 15 years of age
 Weight for occluding internal jugular vein hanging is 2 kg
 Majority of deaths due to Aluminium phosphide occurs in within 24 hours

 During sleep, rectal temperature is 0.5-1.0°C lower
 Drowned body floats in about 12-18 hours in summers 
 Bones constitute about 12% of body weight
 Absence of III molar tooth indicates that the person is definitely under the age of  17 years
 In a dead body, maggots in rainy day are seen in 6 hours.
 Arsenic, Aconite and Dhatura are generally used as homicidal poisons.
 Ricin is the active principle of croton oil seed.
 Abrin is the active principle of abrus precatorius.

Advertisements

METHANOL POISONING

Methanol = Wood alcohol

Absorption from = Git , respiratory tract , skin.

METABOLISM = Methanol is oxidised to formaldehyde by ALCOHOL DEHYDROGENASE. Formaldehyde is converted to formate and then to CO2 and H2O by folate dependent pathways.

TOXICITY : It is due to FORMATE/FORMIC ACID and not due to methanol itself or due to intermediate formaldehyde.

Q1] Methanol toxicity is due to effect of …
[a] Methanol
[b] Formaldehyde
[c] Formate
[d] None

Now the ans is obvious = [c]

 

SYMPTOMS OF TOXICITY :

[1] Most charecteristic symptom of methanol poisoning is = VISUAL DISTURBENCE** likened to ” like being in a snowstorm”.

[2] Symptoms may take some time to appear as because the toxicity is due to its metabolite and it takes some time to build up formate levels so delay of upto 30 hours can be noted before development of visual disturbence and other signs of intoxication.There is typically a delay of the toxic symptoms anywhere from 6-30 hours and longer if ethanol has been co-ingested.

[3] The presence of Bradycardia, prolonged coma , seizures and resistant acidosis imply poor prognosis.

[4] Metabolic abnormality = Metabolic acidosis + Elevated anion gap + Osmolar gap + visual disturbance.

NOTE THAT : Metabolic acidosis + Elevated anion gap + Osmolar gap + Abscence of visual disturbance = ETHYLENE GLYCOL POISONING

 

Now lets see into a MCQ TWIST **

Q1] All of the following are seen in methanol poisoning except….
[a] Blurred vision with clear sensorium
[b] Blurred vision with altered sensorium
[c] Profound metabolic acidosis
[d] IV Ethanol is used in treatment

ANS = [B] In methanol poisoning  the sensorium is relatively preserved 🙂

Methanol toxic dose = 60 -200 ml**

 

[5] Treatment :

[a] First thing to do is to SUPPORT RESPIRATION

[B] Give IV ETHANOL : It has higher affinity for Alcohol dehydrogenase than methanol so saturate it and less formate is formed.

[c] Alkalinisation : To counteract metabolic acidosis SODIUM BICARBONATE

[d] IV FOMEPIZOLE : Inhibitor of Alcohol dehydrogenase AND NOT ALDEHYDE DEHYDROGENASE [AIIMS MAY 2013]

[e] Hemodialysis : Methanol concentration > 50mg/dl is thought to be absolute indication for hemodialysis.

 

 

Kindly also note the route of administration of Ethanol & Fomepizole……its IV***

SOME VERY IMPORANT POINTS ABOUT ETHANOL THERAPY IN METHANOL POISONING

[*] The target ethanol level is 100-150 mg/dl since this is the level that will saturate alcohol dehydrogenase.

[*] Chronic drinkers need a higher rate of ethanol administration.

[*] The intravenous route of administration needs to be done through a central line because 10% ethanol has high osmolarity.

[*]  LOADING DOSE :Give 10% ethanol 7.5 ml/kg IV, over 30 to 60 minutes.

MAINTAINENCE DOSE :The recommended maintenance dose for non-drinkers is 10% ethanol 1 ml/kg/hr IV. For chronic ethanol drinkers, the maintenance dose is 10% ethanol 2 ml/kg/hr IV. If the patient is undergoing haemodialysis, the maintenance dose is 3 ml/kg/hr.

(A solution of about 10% ethanol can be made by mixing 60 ml of absolute alcohol suitable for IV use in 500 ml of 5% dextrose).

 

NOW ANSWER THIS Q

Q3] A case of Methanol poisoning is on treatment with IV Ethanol, IV Fomepizole and sodium bicarbonate but the condition of patient is not improving and the doctor decides to go with Hemodialysis and hemodialysis is started. What happens to requirement of iv ethanol ?

ANS : Hemodialysis rapidly eliminates both methanol and formate thereby reducing blood levels of methanol and formate but in addition it also rapidly eliminates ethanol also so dose adjustment in terms of increased requirement is seen.

 

NOW SOME POINTS ABOUT ETHYLENE GLYCOL

ETHYLENE GLYCOL = ANTIFREEZE SOLUTION

STAGES OF Ethylene Glycol poisoning  :

[1] Transient excitation follwed by CNS depression.

[2] Metabolic acidosis

[3] RENAL FAILURE*** due to oxalate deposition in renal tubules.

Q4] Treatment of ethylene glycol poisoning involves…..
[a] IV Ethanol
[b] IV fomepizole
[c] Hemodialysis
[d] All of these

ANS = [d] All of these : SAME AS METHANOL POISONING

 

Indian Penal Code-Part 2

Chapter 2

SECTION 44: Injury

The word injury denotes any harm whatever illegally caused to any person, in body, mind, reputation or property.

SECTION 51: Oath

Chapter 11

The word oath includes a solemn affirmation substituted by law for an oath, and any declaration required or authorized by law to be made before a public servant or to be used for the purpose of proof, whether in a Court of Justice.

SECTION 191: Giving false evidence

Whoever, being legally bound by an oath or by an express provision of law to state the truth, or being bound by law to make a declaration upon any subject, makes any statement which is false, and which he either knows or believes to be false or does not believe to be true, is said to give false evidence.

SECTION 192: Fabricating false evidence

SECTION 193: Punishment for false evidence

Imprisonment of either description for a term which may extend to seven years, and shall also be liable to fine

SECTION 194: Giving or fabricating false evidence with intent to procure conviction of capital offence

SECTION 195: Punishment of giving false evidence

Imprisonment for a term of 7 years or upwards

SECTION 195 A: Threating any person to give false evidence

SECTION 196: Using evidence known to be false

SECTION 197: Issuing or signing false certificate

SECTION 198: Using as true a certificate known to be false

Whoever corruptly uses or attempts to use any such certificate as a true certificate, knowing the same to be false in any material point, shall be punished in the same manner as if he gave false evidence.

SECTION 199: False satement made in declaration which is by law receivable as evidence

SECTION 200: Using as true such declaration knowing it be false

SECTION 201: Causing disappearance of evidence of offence

SECTION 202:intentional omission to give information of offence by person bound to inform

OTHER worth mentioning Section in exam point of view in this chapter are-

Section 209:Dishonestly making false claim in court

Section211: False Charge of offence in intent to injure

Section228 A:Disclosure of identity of the victim of certain offences like Rape etc.

Section 229A:Failure by person released on bail or bond to appear in court

All other Section which were not mention are mostly related to Giving false information ,false personation or  Horbouring offender etc

Remaining Section will be covered in next post..

Indian Penal code (IPC) at a glance: Part-1

Basic Understanding of Indian penal code-

Chapter-1

Contain section 1 to 5

Deals with punishment of offences committed with in india and out side india.

Chapter-2

Contain section 6 to 52

Definition of Will,Offence,Injury and Death etc

Chapter-3

Contain section 53 to 75

Type of Punishment like Death sentence,imprisonment for life and Fine etc

Chapter-4 (Important)

Contain section 67 to 106

General exceptions of the right of Private Defence,minimum age of punishment,act of intoxication and insanity etc

Chapter-5

Contain 107 to 120

Various Abetment (To encourage/support) sections

Chapter-5 A

Section 120 A & B

Criminal conspiracy

Chapter-6

Contain section 121 to 130

Offence against the state like abetting war and conspiracy etc

Chapter-7

Contain Section 131 to 140

Offence against Army,Navy and Air force.

Chapter-8

Contain Section 141 to 160

Offence against Public Harmony/Peace like-Unlawful assembly,Riot and punishment of riot.

Chapter-9

Contain section 161 to 171

Offence related or by Public Servant

Chapter-10

Contain section 172 to 190

Contempts of Lawful Authority like- absconding or Omission to give notice or information etc

Chapter-11

Contain Section 191 to 229 (Very Important in view of Medical Entrance Exam)

Offence related to false evidence like signing false certificate and perjury etc

Chapter-12

Contain section 230 to 263

Offence related to Coin and Goverment Stamps

Chapter-13

Contain section 264 to 267

Offence relate to Weight and Measurment

Chapter-14 ( Up coming Topic)

Contain section 268 to 294

Offence related to Public Health, safety and Morals-like adulteration of drug,Rash driving and obscene act/songs

Chapter-15

Contain section 295 to 298

Offence related to Religion

Chapter-16 (Very Very Important)

Contain section 299 to 377

Offence affecting Human Body like Homocide,Murder and Hurt etc

Chapter-17

Contain section 378 to 462

Offence against Property

Chapter-18

Contain section 463 to 489

Offence relating to Document and Property Mark like using false trade mark etc

Chapter-19

Contain section 490 to 492

Offence related to Breach of contract of service

Chapter-20 (Up Coming Topic)

Contain section 493 to 498

Offence Related to Marriage like Marrying again and adultery etc

Chapter-20 A (Added in 1983)

Contain section 498 A (Important)

Cruelty by Husband or relatives

Chapter-21

Contain section 499 to 502

Offence related to Defamation (Communication of false statement)

Chapter-22 (Important)

Contain section 503 to 510 

Criminal Intimidation (Bullying weaker person) or Word/Gesture to insult Modesty of a woman

Chapter-23

Contain section 511

Offence not made punishable by other specific section.

This post is important for just ruling out options in Exams…If u have a slight knowledge of chapters and sections that chapter contains,you can easily rule out two options in any exams..In upcoming post I am going to explain important sections considering our PG entrance exams.

Part 2 is coming soon..

FORENSIC BALLISTICS PART 2

NOTE : go through PART 1 OF THIS TOPIC FIRST, FOR BETTER UNDERSTANDING BY CLICKING ON LINK PROVIDED BELOW

http://pguploads.com/2013/04/21/forensic-ballistics-part-1-firearms-and-ammunitions/

Q1] IN A FIREARM INJURY THERE IS BURNING , BLAKENING , TATTOING AROUND THE WOUND, ALONG WITH CHERRY RED COLOUR OF SURROUNDING TISSUE AND IS CRUCIATE IN SHAPE , THE INJURY IS …..[AI 2005]

[A] CLOSE SHOT ENTRY

[B] CLOSE CONTACT EXIT

[C] CONTACT SHOT ENTRY

[D] DISTANT SHOT ENTRY

ANS = [A] CLOSE SHOT ENTRY

Presence of burning, blackening, tattoing signifies it to be close shot entry.

Cherry red colour at entrance wound is due to carbon monoxide that is formed due to flame that is produced from burning of gun powder at the entrance wound. Bcoz flame is found at short range the cherry red colour is seen contact > and close range shots only.

Cruciate shaped wound is seen when wound of entry is over a bone eg skull region . it is more commonly seen in contact shot but can be seen in  close range shots also…

see the diagrams below for better understanding…

Image

NOTE : in CONTACT SHOT  we get muzzle imprint due to impact of muzzle AROUND ENTRY WOUND.

NOW THE FIGURE BELOW MAKES U UNDERSTAND THE APPEARANCE OF CLOSE RANGE SHOT

Image

OTHER IMPORTANT POINT TO BE NOTED IN SHOT GUN ENTRY WOUND IS SPREAD OF INDIVIDUAL PALLETS : upto 2 meteres the shot enters as same mass after which pellets begin to disperse and individual pallet holes may be detected and the distance between 2 most distant holes produced by pallets helps us to calculate range of shot.this has been explained in PART 1 OF THIS TOPIC.

WOUND FEATURES FOR RIFFLED ARMS ARE ESSENTIALY SAME EXCEPT FOR THE FACT THAT RANGE UPTO WHICH FLAME REACHES IS ONLY ABOUT 8-10 CM IN RIFFLED ARMS.

Q2] STELLATE WOUND MAY BE SEEN IN WHICH OF FOLLOWING BULLET WOUNDS…[AI 2009]

[A] CONTACT SHOT

[B] CLOSE SHOT

[C] DISTANT SHOT

[D] TWO FEET DISTANCE

ANS : [A] CONTACT SHOT OVER HARD AREA EG SKULL. Note that in soft areas as abdomen contact shot will be circular.

Q3] IN FIREARM INJURY , ENTRY WOUND BLAKENING IS DUE TO…[AI2002]

[A] FLAME

[B] HOT GASES

[C] SMOKE

[D] UNBURNT GUN POWDER

ANS:[C] SMOKE ( see figure above )

Q4] IN TANDEM BULLET NO OF BULLET FIRED IS [AIIMS NOV 2007]

ANS =2

Q5]GUN SHOT RESIDUE ON HANDS CAN BE DETECTED BY [AIIMS NOV 2005]

ANS =DERMAL NITRATE TEST

Q6]A BULLET FIRED FROM GUN IS NOT RELEASED . IT IS EJECTED OUT IN SUBSEQUENT SHOT.. IT IS KNOWN AS [AIIMS NOV 2003]

ANS =TANDEM BULLET

Q7] GUN SHOT IN SKULL , FOLLOWING ARE FEATURES EXCEPT….[UP 2004]

[A] Entrance wound is bevelled in the inner table

[B] Entrance wound is beveled in outer table

[C] Exit wound is punched out in inner table

[D] Exit wound is beveled in outer table

ans =[B]

During entry bullet produces clean cut hole in outer table and beveled hole in inner table . During exit bullet produces punched out hole in inner table and beveled hole in outer table.

Q8] DIRT COLLAR /GREASE COLLAR IS SEEN IN ..[ JIPMER 2005]

[A] Punctured wound by sharp weapon

[B] Lacerated wound

[C] Firearm entry wound

[D] stab wound

ans =[c]

DO READ PART 1 OF THIS TOPIC BY CLICKING ON LINK BELOW

http://pguploads.com/2013/04/21/forensic-ballistics-part-1-firearms-and-ammunitions/

SUGESSIONS/ FEEDBACK R WELCOME

PLZ RATE THIS TOPIC IF U LIKE THIS