The absence of a pulse and the fact that the body gradually turns blue (cyanosis) are among the physical characteristics of death. When the brain has stopped functioning there will be no narrowing of the pupils of the eyes when a light is shone on them. The body temperature drops and in the end the body becomes quite rigid (rigor mortis). Finally the skin turns purplish-blue in colour as a result ofleaking out of the (post mortem discoloration). Within a few hours after death the decomposing process starts as a result of autodigestion. Enzymes in the tissue begin to break down the proteins of the and finally the themselves are totally destroyed. However, the fact that a person does not have a pulse or that his skin is turning blue, does not always imply that the person is dead. Someone suffering from a serious heart condition may suddenly experience (spontanuous) cardiac arrest. For certain operations such as open heart surgery cardiac arrest may be effected artificially.
In the first example a doctor may start resuscitation, applying external heart massage if necessary combined with mouth-to-mouth resuscitation, in order to restore thecirculation and the respiration. In the case of artificially applied cardiac arrest, the heart can be restarted by a slight electrical shock. Every hospital has at least one resuscitation unit in case a person has a heart attack, and many ambulances are equipped with resuscitation apparatus. As well as restoration of the circulation and respiration by means of external heart massage and mouth-to-mouth resuscitation doctors are also able in such cases to apply, if necessary, an electric shock externally in order to restart the heart. This technique is called defibrilation. A doctor may also try to restart the heart with an injection of the hormone adrenaline. Only qualified practitioners are allowed to apply defibrilation and to administer adrenaline injections in order to prevent death and this has to be done within a very short time after the cardiac arrest has occurred.
The reason for this is that when circulation stops the brain will be deprived of oxygenated blood and without oxygen brain cells die very rapidly. A resuscitation effort that is initiated too late but succeeds in restarting the heart can have tragic consequences, leaving the patient brain-damaged. And as a result of the brain damage the patient may be severely disabled for the rest of his life. Everybody should know the technique of applying mouth-to-mouth resuscitation. Many lives have been saved because people gave non-professional assist- ance with the correct life-saving techniques at the right moment. It goes without saying that here too the same considerations apply concerning the time the help is initiated. When the patient is terminally ill and resuscitation would only prolong the suffering, it may be decided to refrain from doing it.