DEFINITION
Postmortem artefacts are any changes caused or features introduced in a body after death (accidental or physiologically unrelated to the natural state of the body) that are likely to lead to misinterpretation of medico-legal significant ante-mortem findings. Postmortem Analysis of PostPostmortemefacts:
Often, the doctor is the chief source of evidence upon which legal decisions are made. The decision of acquittal or imprisonment depends entirely on the evidence presented. Therefore, the doctor should learn to draw logical and correct conclusions, instead of forming hasty judgments.
Types of Postmortem Facts-
Before death
During Death
Between death & autopsy
During autopsy
BEFORE DEATH
Death due to convulsive disorder
Bruising
Rupture of muscles
Subconjunctival hemorrhage
Joint dislocation
Tongue, lips bite
Death due to hemorrhagic diathesis
Petechial hemorrhage
Bleeding in the joint space
Bleeding in other potential spaces- pleural, peritoneal
Death due to respiratory distress
Cyanosis
Salivation
Petechiae
Death due to ICP
Flattening of gyri
Edematous
Herniation of unci
Death due to burns
Heat ruptures may resemble lacerated or incised wounds.
Heat haematoma may simulate an extradural hemorrhage.
Postmortemneous
Postmortem injuries produced from the bumping of the body into rocks, coral, or marine structures should be distinguished from ante-mortem trauma.
Similarly, fractures caused by a fall into the water from a height due to the body striking forcibly against some solid object, or mutilation from boat propellers, or loss of fingers, toes, eyelids, lips, genitals, or rarely whole portions of the bodyoccurringg from the attacks of marine animals should also be distinguished
DURING DEATH
AGONAL ARTEFACTS:
Regurgitation and aspiration of gastric content are common artifacts. It may be seen in natural deaths, as a terminal event, or due to handling of the body, or due to resuscitation.
One of the effects of asphyxia is to cause vomiting due to medullary hypoxia.
Oesophagogastromalacia is rarely seen in persons who die within hours or days after receiving severe head injury with cerebral damage. This occurs due to autodigestion; stomach contents are spilled into the left chest cavity or the left subphrenic area.
Signs of muscle spasm, if it occurred (bruise, abrasion, subconjunctival hemorrhage, etc.
Signs of asphyxia include respiratory distress from any cause, such as petechiae, cyanosis, etc.
II. RESUSCITATION ARTEFACTS:
The injection marks of resuscitation are usually found in the cardiac region or on the extremities. In intracardiac injection, the heart may show contusion, and blood may collect in the pericardium.
A defibrillator applied to the chest may produce a ring-like contusion.
External massage may cause bruising of the anterior chest wall, hemorrhage into subcutaneous tissues and pectoral muscles, fracture of several ribs, and sometimes of the sternum.
Vigorous resuscitation with a thoracotomy and internal cardiac massage produces air embolism. When a positive pressure breathing apparatus (respirator) is used for resuscitation, it produces acute emphysema, sometimes with subpleural blebs, air in the mediastinum, or tension pneumothorax
Contusions of soft tissues of the neck may be mistaken for homicidal strangulation.
These resuscitation injuries may be mistaken for those due to assault or steering-wheel impact injuries.
Damage to the mouth, palate, pharynx, and larynx can occur from attempts to introduce a laryngoscope.
Mouth-to-mouth breathing may cause contusions of the face, neck, and damage to the lips and inner gums when the face and neck have been gripped by a hand.
BETWEEN DEATH AND AUTOPSY
Artifacts due to the handling of the body:
Occasionally, fractures of the ribs or the bones of extremities, or the cervical spine may occur by rough handling of bodies, especially if there is severe osteoporosis
Contusion of the occipital region may be caused if the head of the corpse is allowed to fall on a hard surface during handling.
Fresh abrasions may be produced due to the roughness of the body, which was originally on them, during the transfer of the body from the scene of the crime.
crimedertaker’s fracture is a subluxation of the lower cervical spine due to tearing of the intervertebral disc at about C6-C7.
Atrefacts Related to Rigor Mortis:
The handling of the body may cause a break in the rigor at least partially, which may mislead the doctor in the estimation of the time of death
The onset and duration of rigor may be altered by atmospheric conditions, such as extreme heat or cold, or ante-mortem conditions, including muscular state, exhaustion, wasting diseases, and hyperthermia due to infections.
Rigor affecting the heart may simulate concentric hypertrophy of the heart.
Rigor mortis may accentuate the rugae or fix a point of contraction to give a pseudo-hourglass, which is readily removed by traction.
Rigor in the pylorus causes it to be unduly firm and contracted.
APostmortemlated to Post-mortem Lividity:
The color of postmortem stains is usually bluish-purple. Certain poisons may change the
Color of the hypostatic area, e.g., cherry-red color in CO poisoning, bright-red color in HCN poisoning, brown or chocolate color in poisoning by nitrites, potassium chlorate, and aniline, dark-brown color in phosphorus poisoning.
Patches of hemorrhage, sometimes quite large and confluent, can occur in the tissues behind the esophagus at the level of the larynx.
‘Banding’ of the esophagus may be seen, especially when the tissues decompose.
Artifacts due to Decomposition:
Intense localized lividity of the skin, due to hypostasis, or the displacement of internal blood. Decomposition, the pressure of gases, produces pseudo-bruising that may simulate ante-mortem bruises.
Internal hypostasis with hemolysis of red cells may resemble hemorrhage, especially in the meninges, kidneys, and retroperitoneal tissues.
In a dead body lying on its back, blood accumulates in the posterior part of the scalp due to gravity
Bloody fluid may be found in the mouth and nose in decomposed bodies, which is marked in conditions that produce pulmonary edema.
Accumulation of blood in the tissues of the neck in drowning may simulate ante-mortem hemorrhage due to strangulation. During Decomposition, blood becomes darker, causing the brain, lungs, heart, and other organs to appear congested, which may be mistaken for signs of asphyxia.
Artefacts due to Animal and Insect Bites:
Rodents gnaw away at issues in localized areas. They produce shallow craters with irregular borders by nibbling and leave long grooves.
The bites by dogs are clear-cut, with deep impressions of teeth in a small area.
Cat bites are usually very small and round.
Marks produced by insects (ants or roaches) are dry, brown with irregular margins, and are typically seen in moist parts of the body, e.g., ears, armpits, groins, scrotum, anus, etc.
Rarely, injuries caused by crabs may simulate stab wounds.
Aquatic animals may cause the same postmortem findings in the dead body.
Pospostmortemmorrhage:
Before postmortem clots, an antemortem injury may damage a blood vessel and produce hemorrhage.
After death, blood may collect in the pleural cavities due to wounds produced on the chest wall and the lung tissue.
After death, blunt impact may lacerate blood vessels and displace red cells into the tissue spaces.
Artifacts due to Chemicals:
In automobile accident postmortem crashes, exposure postmortem causes postmortem detachment of the epidermis
Artifacts resulting from postmortem hypostasis due to refrigeration are observed in bodies. Postmortem refrigeration of infants usually solidifies the subcutaneous fat, which produces a prominent crease where there was a normal skin fold of the neck, which resembles a strangulation mark.
Toxicological Artefacts:
A faulty technique in collecting a sample, especially a blood sample, can yield false results.
When blood is collected from the heart using a long needle, it may become contaminated with stomach contents or regurgitated esophageal contents.
Suppose blood is contaminated with pericardial or pleural fluids. False results are obtained regarding alcohol.
Embalming Artefacts:
The trocar wound may simulate a stab wound.
Interment and exhumation Artefacts:
In those that have been buried, fungus growth is observed at the orifice of the eyes and sites of open injuries.
Grave-postmortem produce postmortem, abrasions, and lacerations
DURING AUTOPSY
Air in Blood Vessels:
Pulling of the dura in the sagittal line will cause the air to enter the blood vessels
Skull Fractures:
Fractures of the skull, usually in the middle fossae, may be produced due to partial sawing and forceful pulling of the skull cap or due to partial sawing and then using a chisel and hammer to loosen the skull cap.
Visceral Damage:
Rough handling of the brain during removal may produce tears of the midbrain.
Rough handling of the liver during removal may produce tears of the diaphragmatic surface, which simulate ante-mortem lacerations.
If the neck structures are pulled too hard during autopsy to drag out the thoracic viscera, they may be torn, and also transverse intimal tears may be produced in the descending aorta and vessels at the top of the brain.
Extravasation of Blood:
In the case of a suspected cranial injury, the body should be opened, and the cardiovascular system decompressed by opening the heart before the head is opened.
Fracture of the Hyoid Bone:
When the tongue and neck structures are firmly grasped and pulled upon while removing the neck organs, the hyoid bone and thyroid cartilage may be fractured, especially in old persons.
Injury to Blood Vessels:
While dissecting the neck structures, if toothed dissecting forceps are used, it may damage the intima of the carotid artery, which resembles a tear, as is seen in the case of strangulation.
Toxicological Artefacts:
They may be introduced due to: (a) Contamination of viscera with stomach contents during autopsy, or by putting all the organs in one container, or by using contaminated instruments or containers. (b) Faulty technique in collecting the sample (c), incorrect storage, or use of preservatives.