SIGNS OF DEATH
These are divided into immediate and late signs.
I- Immediate signs due to:
1- Loss of the vital functions of the brain (cerebral cortex and brain stem).
2- Permanent cessation of circulation.
3- Permanent cessation of respiration.
1) Signs due to loss of the vital functions of the brain:
A) Signs due to death of cerebral cortex:
1. Flat EEG: Flat isoelectric curve or lack of response i.e. "cerebral silence". Flat EEG alone should never be taken as a conclusive evidence of death, because temporary silence (temporary flat EEG) can follow many conditions, such as:
* Trauma, including birth injury. * Circulatory arrest.
* Prolonged fainting attack. * Hypoglycaemia.
* Narcotic and CO Poisonings. * Encephalitis.
* Epilepsy. * Electrocution.
The period of such temporary silence never exceed 4 hours in those who recover. It was recommended therefore that a minimum period of 6 hours should pass before EEG is repeated for recording a second time to ensure cerebral death.
2- Cessation of circulation through the retina: blood in the retinal veins breaks up into segments within 10 seconds of clinical death. Segmentation is indicative of cerebral death more than cessation of circulation.
3- Lack of responsiveness to internal and external environment.
4- No muscular movement with generalized flaccidity.
B) Signs due to brain stem death:
*All brain-stem reflexes are absent.
- Pupils are fixed, dilated and not reactive to strong stimuli.
- Absent corneal reflexes.
- The vestibulo-ocular and cephalo-ocular reflexes are absent.
- Absent gag and cough reflexes.
* No spontaneous respiration.
* Falling of arterial blood pressure without support by drugs or other means.
2) Cessation of circulation:
- If the heart sounds are not heard for a continuous period of 5 minutes, cessation of circulation is diagnosed.
- Absence of radial or carotid arteries pulsation.
- Flat ECG.
It may be very difficult to hear the heart sounds in the following conditions:
1- Cases of feeble heart sounds.
2- Cases of thick chest wall.
3- Cases of emphysema.
4- Conditions of suspended animation.
In doubtful cases, an ECG will record the electrical activity of the feeble beats.
3) Cessation of respiration:
It must be complete and continuous to constitute a proof for death. Respiration may cease temporarily for a very short period without death in some conditions, such as:
1- An apparently drowned person.
2- In newly born infants.
Cessation of respiration can be detected by careful inspection of the chest and abdomen. Absence of air-entry may be demonstrated by auscultation for five minutes.
II- Late signs of death:
1- Changes in the skin: these are pallor of the skin and loss of its translucency and elasticity. Loss of skin translucency denotes absence of circulation, and may be demonstrated by inspecting the webs in between the fingers in transmitted light.
2- Changes in the muscles: muscular changes are of 2 forms:
a) Primary flaccidity b) Contact flattening.
a- Primary flaccidity:
After death, there is generalized muscular relaxation, leading to drop of the lower jaw. The muscles become soft and flabby. The joints are flexible and the sphincters relax resulting in incontinence of urine and faeces.
N.B.: The pupils and cardiac muscle dilate after death, thus the size of the pupils or flaccidity of the cardiac muscle are not good indicators of their antemortem conditions.
Primary flaccidity must be distinguished from the secondary flaccidity, which is synchronous with the onset of putrefaction. In primary flaccidity, death is still somatic, the muscles still react to the external stimuli as electrical stimuli, and the tissues are still alkaline in reaction.
b- Contact flattening:
It is loss of the muscular tone and elasticity. When the body is kept in the supine position on a solid surface after death, its convex parts (i.e. buttocks, and calves) will lose their convexity and become flattened from the pressure.
3- Ocular changes: These include:
1- Reduction of the intra-ocular pressure (due to cessation of circulation in retinal vessels and softening of the anterior chamber). (see p. 28)
2- Clouding (haziness) or loss of corneal luster except in cases of death from asphyxia or poisoning by cyanide or CO.
3- Ophthalmoscopic examination reveals pale white papillary disc and segmentation of the retinal veins and empty retinal arteries.
4- "Taches Noir de la Sclerotique" appear on the sclera within 3 hours from death, if the eyes remained open. These are areas of brownish discoloration formed on the exposed sclera. These spots are triangular, based directly on the cornea, more often on the outer more than the inner side of the globe. These spots are possibly due to dissication of the tissues or the formation of cellular debris setting there on.
Apparent death (suspended animation):
- It is death like state, in which there is temporary suspension of the heart beats and respiration, hence its name suspended animation.
- It is a state where the vital processes of the body are depressed to a minimum compatible with life. However, respiration is not ceased at the cellular level, hence resuscitation is still possible.
- It may persist from few seconds to several minutes.
It may occur in the following conditions:
1- Electrocution.
2- Drowning especially in cold water.
3- Hypothermia, with marked depression of the vital processes owing to lowered metabolism, anoxia and inhibition of the respiratory enzymes.
4- Starvation where the basal metabolic rate is at its lowest level and is accompanied with depression of cardiovascular and respiratory functions.
5- Heat stroke.
6- Shock following accident or anaesthesia.
7- Poisoning with narcotics causing deep coma.
8- Cerebral concussion.
9- Newborn.
It can be induced voluntarily by some persons (Yogist) and they can continue it for longer periods.
Complications of apparent death:
- Pulmonary oedema. - Convulsions.
- Some neurological disturbances.
Diagnosis: in order to avoid mistakes in diagnosis of this condition, the followings must be done:
1. ECG
2. Clinical examination for brain stem reflexes
3. EEG
4. Auscultation for heart and chest.
5.Ophthalmoscopic examination for appearance of any early postmortem changes in the eye.
These are divided into immediate and late signs.
I- Immediate signs due to:
1- Loss of the vital functions of the brain (cerebral cortex and brain stem).
2- Permanent cessation of circulation.
3- Permanent cessation of respiration.
1) Signs due to loss of the vital functions of the brain:
A) Signs due to death of cerebral cortex:
1. Flat EEG: Flat isoelectric curve or lack of response i.e. "cerebral silence". Flat EEG alone should never be taken as a conclusive evidence of death, because temporary silence (temporary flat EEG) can follow many conditions, such as:
* Trauma, including birth injury. * Circulatory arrest.
* Prolonged fainting attack. * Hypoglycaemia.
* Narcotic and CO Poisonings. * Encephalitis.
* Epilepsy. * Electrocution.
The period of such temporary silence never exceed 4 hours in those who recover. It was recommended therefore that a minimum period of 6 hours should pass before EEG is repeated for recording a second time to ensure cerebral death.
2- Cessation of circulation through the retina: blood in the retinal veins breaks up into segments within 10 seconds of clinical death. Segmentation is indicative of cerebral death more than cessation of circulation.
3- Lack of responsiveness to internal and external environment.
4- No muscular movement with generalized flaccidity.
B) Signs due to brain stem death:
*All brain-stem reflexes are absent.
- Pupils are fixed, dilated and not reactive to strong stimuli.
- Absent corneal reflexes.
- The vestibulo-ocular and cephalo-ocular reflexes are absent.
- Absent gag and cough reflexes.
* No spontaneous respiration.
* Falling of arterial blood pressure without support by drugs or other means.
2) Cessation of circulation:
- If the heart sounds are not heard for a continuous period of 5 minutes, cessation of circulation is diagnosed.
- Absence of radial or carotid arteries pulsation.
- Flat ECG.
It may be very difficult to hear the heart sounds in the following conditions:
1- Cases of feeble heart sounds.
2- Cases of thick chest wall.
3- Cases of emphysema.
4- Conditions of suspended animation.
In doubtful cases, an ECG will record the electrical activity of the feeble beats.
3) Cessation of respiration:
It must be complete and continuous to constitute a proof for death. Respiration may cease temporarily for a very short period without death in some conditions, such as:
1- An apparently drowned person.
2- In newly born infants.
Cessation of respiration can be detected by careful inspection of the chest and abdomen. Absence of air-entry may be demonstrated by auscultation for five minutes.
II- Late signs of death:
1- Changes in the skin: these are pallor of the skin and loss of its translucency and elasticity. Loss of skin translucency denotes absence of circulation, and may be demonstrated by inspecting the webs in between the fingers in transmitted light.
2- Changes in the muscles: muscular changes are of 2 forms:
a) Primary flaccidity b) Contact flattening.
a- Primary flaccidity:
After death, there is generalized muscular relaxation, leading to drop of the lower jaw. The muscles become soft and flabby. The joints are flexible and the sphincters relax resulting in incontinence of urine and faeces.
N.B.: The pupils and cardiac muscle dilate after death, thus the size of the pupils or flaccidity of the cardiac muscle are not good indicators of their antemortem conditions.
Primary flaccidity must be distinguished from the secondary flaccidity, which is synchronous with the onset of putrefaction. In primary flaccidity, death is still somatic, the muscles still react to the external stimuli as electrical stimuli, and the tissues are still alkaline in reaction.
b- Contact flattening:
It is loss of the muscular tone and elasticity. When the body is kept in the supine position on a solid surface after death, its convex parts (i.e. buttocks, and calves) will lose their convexity and become flattened from the pressure.
3- Ocular changes: These include:
1- Reduction of the intra-ocular pressure (due to cessation of circulation in retinal vessels and softening of the anterior chamber). (see p. 28)
2- Clouding (haziness) or loss of corneal luster except in cases of death from asphyxia or poisoning by cyanide or CO.
3- Ophthalmoscopic examination reveals pale white papillary disc and segmentation of the retinal veins and empty retinal arteries.
4- "Taches Noir de la Sclerotique" appear on the sclera within 3 hours from death, if the eyes remained open. These are areas of brownish discoloration formed on the exposed sclera. These spots are triangular, based directly on the cornea, more often on the outer more than the inner side of the globe. These spots are possibly due to dissication of the tissues or the formation of cellular debris setting there on.
Apparent death (suspended animation):
- It is death like state, in which there is temporary suspension of the heart beats and respiration, hence its name suspended animation.
- It is a state where the vital processes of the body are depressed to a minimum compatible with life. However, respiration is not ceased at the cellular level, hence resuscitation is still possible.
- It may persist from few seconds to several minutes.
It may occur in the following conditions:
1- Electrocution.
2- Drowning especially in cold water.
3- Hypothermia, with marked depression of the vital processes owing to lowered metabolism, anoxia and inhibition of the respiratory enzymes.
4- Starvation where the basal metabolic rate is at its lowest level and is accompanied with depression of cardiovascular and respiratory functions.
5- Heat stroke.
6- Shock following accident or anaesthesia.
7- Poisoning with narcotics causing deep coma.
8- Cerebral concussion.
9- Newborn.
It can be induced voluntarily by some persons (Yogist) and they can continue it for longer periods.
Complications of apparent death:
- Pulmonary oedema. - Convulsions.
- Some neurological disturbances.
Diagnosis: in order to avoid mistakes in diagnosis of this condition, the followings must be done:
1. ECG
2. Clinical examination for brain stem reflexes
3. EEG
4. Auscultation for heart and chest.
5.Ophthalmoscopic examination for appearance of any early postmortem changes in the eye.
+ comments + 1 comments
Thanks for the info. Its quite enlightening.
Post a Comment