Autopsy, necropsy and post-mortem examination are synonymous, although post-mortem examination can have a broader meaning encompassing any examination made after death, including a simple external examination.
In general terms, autopsies can be performed for two reasons: clinical interest and medico-legal purposes.
The clinical autopsy is performed in a hospital mortuary after consent for the examination has been sought from and granted by the relatives of the deceased. The doctors treating the patient should know why their patient has died and be able to complete a death certificate even in the absence of an autopsy.
These examinations have been used in the past for the teaching of medical students etc. and for research.
The medico-legal autopsy is performed on behalf of the state.
A poor autopsy is worse than no autopsy. In medico-legal autopsy, often the history is absent, sketchy, doubtful.
The aims of these examinations are much broader than those of the clinical autopsy and include:
to identity of the body;
• to estimate the time of death;
• to identify and document the nature and number
• to interpret the significance and effect of the injuries;
• to identify the presence of any natural disease;
• to interpret the significance and effect of the natural disease present;
• to identify the presence of poisons; and
• to interpret the effect of any medical or surgical treatment.
Taken at its broadest, autopsies can be performed by any doctor, but ideally they should be performed by a properly trained pathologist in mortuary at day-time, without the presence of any unauthorized person.
Rules for medico-legal autopsy:
- The body should be labeled as it arrives the mortuary.
- Conducted never in a private room, only in mortuary.
- However, autopsy is done at the site when advanced level of putrefaction, causing difficulty in transportation.
- Conducted only when official order from police or magistrate.
- Done without undue delay after receiving the order.
- M.O. should read the inquest report carefully to know the apparent cause and circumstance of the death.
- Conducted in day light as far as possible.
- The body must be identified by the police constable who accompanies it.
- In unidentififed bodies, marks of identification, photographs and finger prints should be taken.
- No unauthorized person should be present during autopsy.
- The investigating police officar may be present.
- The details are noted and sketches are made.
- Both positive and negative findings should be recorded.
- After autopsy, the body should be handed to the police constable.
- The PM report should not be handed to the party.
1.The pre-amble: mentions the authority ordering the examination, date and place of the examination, name and sex of the deceased.
2.The body of the report: consists of detailed external and internal examination, focusing nature, direction, exact situation and dimension of the wounds, diagrams are of value.
3.Conclusion: as to the cause of death should be concise in clear language and honest. It should be followed by signature and qualification of the doctor.
- The clothing should be listed and examined, type of garment, colour, tears, loss of button indicating a struggle is explained as each item is removed from the body. Blood stain, grease, seminal stain, poison, vomit should be kept for analysis. Clothes should be placed in clean separate bags.
- Nail scrapping- any visible fiber or other matter at the hand should be removed and placed in envelope. Ten small envelopes are labeled, one for each finger.
- Height and weight, general state, body built.
- General condition of the skin- rash, petechiae, colour.
- General description- age, sex, colour, race, nutrition, hair, scar, tatoo, moles, circumcision, pupils.
- Vaginal and anal swaps, pubic hair should be combed through. Matted pubic hair should be cut with scissors and the samples of pubic hair should be taken.
- The stain of mud, vomit, faeces, gun powder described.
- The presence of signs of disease eg., edema of legs, surgical emphysema, skin disease etc.
- The time since death should be noted from rectal temperature, rigor mortis, post-mortem hypostasis, putrefaction.
- The face examined for frothy fluid at the mouth and nose, cyanosis, petechiae, pallor etc.
- The eyes examined for conjunctiva, opacity of the cornea and the lens, petechiae. The ears for leakage of blood or CSF.
- The neck examined for bruises, finger nail abrasion, ligature mark.
- The abdomen, thorax, thyroid, breast, back, external genitalia and the natural orifices should be noted.
- The position of limbs should be noted. Hands examined for injuries, defense wounds, electric mark etc. and anything grasped in the closed fist.
- Skin incison-
‘I’ shaped from the chin to symphysis pubis.
‘Y’ shaped incision from acromial process down below the breast to xiphoid and down to the symphysis pubis.
Modified ‘Y’ shaped incision- incision made in the midline from supra sternal notch to the symphysis pubis. The incision extends from the suprasternal notch over the clavicle to its centre on both sides and then passes upwards over the neck behind the ear.
- Abdomen- The recti muscle of the abdomen are divided about 5cm above the symphysis pubis, peritoneum is cut upto xiphoid, the condition of abdominal cavity and the organs is observed. Blood, pus if seen in the abdominal cavity, should be measured.
- Neck- a block should be placed under the shoulder to extend the neck, the skin dissection carried out immediately deep to skin to the lower border of lower jaw, sternomastoid muscle is freed from its attachments, the trachea, larynx, pharynx are pulled away from the pre-vertebral tissue by blunt dissection.
- Mouth- a knife inserted under the chin through the floor of mouth, cut along the sides of the mandible, to the angle of mandible dividing the neck muscles attached to the jaw. The soft palate is then cut to include the uvula and tonsils with tongue and neck organs to be removed. The knife is turned backwards and laterally to divide the posterior pharyngeal wall. The larynx and pharynx are pulled down, the dissection is then carried distally through the prevertebral muscles on the anterior surface of the cervical vertebra.
- Chest- pneumothorax should be noted by creating a pocket filled with water before the proper chest dissection. The wall is punctured with the knife under the water. The chest is opened by cutting the costal cartilage beginning from the second cartilage near the costo-chondral junction. The pleural cavity should be examined. Note the lumen of the main pulmonary vessels, right atrium and ventricle for embolism, distension or collapse of lungs, pleural cavity for fluid, pus, adhesions. Note the pericardium for cardiac temponade, collect blood sample from the heart for toxicological examination.
- Air embolism- in the heart can be found by cutting the pericardium anteriorly and grasping the edge with hemostat on each side. The pericardial sac is filled with water and the heart is punctured with scalpel and twisted few times to release escape of bubbles of gas.
- Fat embolism- if suspected the pulmonary artery should be dissected under water and the escape of fat droplets noted.
- There are two distinct methods of removing the viscera from the abdominal cavity and thoracic cavity:
2.Rokitansky method- removing all the organs ‘en masse’.
The organ should be described based on size, shape, surface, consistency, cohesion, cut surface.
- Esophagus: the esophagus is cut open from the posterior surface up to the cardiac end of the stomach. If death occurred due to rupture of esophageal varices, the break in the lower end should be noted.
- Lungs: look for thrombi, emboli. The lung organ is crossed across from the apex to the base with a large brain knife, producing an anterio-posterior slice and examined for consolidation, edema, emphysema, tumor, infarction. The smaller bronchi are examined for mucosal thickening, infection and blockage.
- Aorta: whole length of aorta is cut on its posterior surface from the iliac vessels, around the arc upto the aortic valve to note chronic aortitis, obstruction of coronary arteries.
- Heart: is held at the apex and lifted upwards and the vessels are cut as far away as possible. This isolated heart is opened in the direction of the flow of blood. The right atrium is cut between the opening of superior and inferior venecava. Through the right atrium and through the tricuspid orifice, the right ventricle is opened along the lateral margin.
- Note whether the content of right ventricle and auricle is fluid blood, currant jelly clot or chicken-fat clot. The left atrium is cut along the lateral wall, extending through the mitral orifice and passes along the lateral margin of the left ventricle upto the apex. After the blood clots in the cavities are removed, the measurements of the valves, circumference and thickness of ventricles are taken. The coronary arteries are examined by making serial cross sections along the entire course of vessel about 2-3mm apart.
- Agonal thrombi: seen in case of persons dying slowly with circulatory failure, a firm tough pale yellow thrombus, usually on the right side of the heart, filling the right auricle and ventricle and pulmonary artery. It branches like a tree like cast. In the left ventricle, agonal thrombi are not so big.
Post mortem clots: 2 types-
- Black currant jelly: soft, lumpy, uniformly dark red, moist clot formed when the blood clots rapidly.
- Chicken-fat clot: when red cells sediment before the blood coagulates. The red cells produces a clot similar to the first type. Above this a pale or bright yellow layer of serum and fibrin is seen called chicken fat. It is soft, elastic jelly like.
- Usually a mixture of the two is found. Post-mortem clots are moist, smooth, shiny, homogenous, rubbery, not attached to the underlying wall, and there are no fine white lines of fibrin (striae of zahn).
- Stomach: opened along its greater curvature from the cardiac to pyloric end. The contents are examined for food, digestion, smell, colour. In massive hemorrage, the stomach is filled with large soft clots which may take the form of a task of gastric outline.
- Intestine: the superior mesenteric vessels are examined for thrombi, emboli. The small intestine is opened along the line of mesenteric attachment.
- Liver: weight, size, colour, injury are noted. It is cut into slices 2cm thick which run in the long axis. Amoebic abscess are usually single large and confined to the right lobe. Pyogenic abscess are multiple. In fatty liver, cut section is greasy. In portal cirrhosis, the liver is sturded with nodules, 1-3mm in diameter (micro nodular).
- Spleen: removed by cutting through its pedicle. Note the size, weight, rupture.
- Pancreas: sliced by a series of cuts at right angle to the long axis which gives the best exposure of ductal system.
- Kidney: renal artery ostia are examined. The capsule of the kidney is stripped, the kidney is sectioned longitudinally to split in half and open the pelvis to see calculi and inflammation.
- Female genitalia/uterus: the tube, the ovaries and the uterus are freed from the pelvis and are removed. If the uterus contains a fetus, its age should be determined.
- Head: head is fixed by head rest. A coronal incision is made in the scalp from the mastoid process just behind ear and carried over the vertex to the opposite mastoid. The scalp is reflected forwards and backwards. The saw line is made in slightly ‘V’ shaped direction so that the skull cap will fit exactly back into the correct position. The meninges are examined and the brain is examined.