Brain death


With the term brain death is the irreversible failure of crucial areas of the brain described. Brain death diagnostics is a regulated condition for organ donation by the German Medical Association. If a brain death is definitely diagnosed, a person in Germany is considered dead. Read all about brain death here!

ICD codes for this disease: ICD codes are internationally valid medical diagnosis codes. They are found e.g. in medical reports or on incapacity certificates. G93ArtikelübersichtHirntod

  • description
  • symptoms
  • Causes and risk factors
  • Examinations and diagnosis
  • treatment
  • Disease course and prognosis

Brain death: description

For the first time in the second half of the twentieth century, physicians were confronted with being able to keep deeply-conscious, non-respiratory patients alive with machine and drug support. In the late 1950s, the first brain death definition was published. Only later was the organ donation option for brain dead.

The brain death concept is widespread almost worldwide. According to the Federal Center for Health Education (BZgA) occurs in one per cent of the approximately 400,000 dying in German hospitals a brain death per year before the cardiac arrest on. In Germany, statistically speaking, only every second brain death diagnosis is related to a planned organ or tissue donation.

How is the brain death defined?

The concept of brain death is often confusing and controversial, making it a subject of concern for many people. An American study showed that only 28 percent of enlightened brain stem volunteers could give a proper brain death definition. Therefore, the first problems arise with the question "what is brain death".

In the details, the definitions differ internationally. However, the brain death definition always states that there is an irreversible brain function failure. At the same time, however, the spinal cord, even part of the central nervous system, may still function (restricted). The brain-dead person has a measurable pulse and blood pressure in the intensive care unit. So the body is still able to balance various bodily functions. However, this is only possible with intensive, mechanical support.

The decisive factor is that a brain-dead person can not breathe spontaneously so that the heart and circulation come to a standstill without mechanical ventilation. The German Ethics Council agreed that brain death is a sufficient condition for organ removal. However, a minority of the German Ethics Council sees brain death as not a "sufficient condition" for the death of a human being.

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Brain death: symptoms

If a person is brain dead, they can not breathe on their own. Evidence of brain death is a lack of response to pain (no grimacing), no respiratory drive and the loss of brain stem reflexes. These reflexes are mediated by the brain stem, an important part of the brain. These include the strangling and coughing reflexes. Even the loss of eye reflexes can be an indication of brain death.

Most of the patients have low blood pressure and need circulation-supporting medications. At the same time, however, functions of other organs - apart from the brain - are preserved. Brain-dead people can drop, urinate, or even sweat. The body can thus maintain the internal balance (homeostasis) with the help of intensive care. Also, motor reactions, which are usually mediated through the spinal cord, can occur. This includes the so-called Lazarus sign. These are reflex reactions mostly from the arms or legs. Also convulsions of the facial muscles do not exclude a brain death basically. Such signs can be misinterpreted as signs of life and lead to an additional psychological burden on relatives.

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Brain death: causes and risk factors

Ultimately, an oxygen deficiency of the brain is always the cause of brain death. Already an interruption of the oxygen supply of a few minutes can lead to a failure of the brain, the parent control of the human body.

In more than half of all cases, cerebral hemorrhage is the cause of brain death. Cerebral haemorrhages are usually the result of long-standing hypertension or a previously damaged blood vessel. Because the bony skull can not expand, the pressure on the brain increases due to the bleeding, so that the blood circulation in the brain-supplying vessels comes to a standstill.

The second most common cause is so-called ischemic-hypoxic brain damage, which is due to an oxygen deficiency of the brain, for example, due to a cardiovascular arrest caused. Only in third place of the brain death causes are accidents with craniocerebral injuries. Other causes include brain infarcts, tumors, brain inflammation and the appearance of a hydrocephalus (hydrocephalus).

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Brain death: examinations and diagnosis

In Germany, brain death diagnostics are regulated in detail by the German Medical Association in accordance with the Transplantation Act (TPG). Most recently, the relevant directive in Germany was revised in March 2015. Precise and strict rules are intended to reduce uncertainties among medical staff, but above all fears and worries of relatives.

Brain death diagnostics must follow a well-regulated procedure. If the regulations are followed exactly, the brain death diagnosis is considered safe. The purpose of the detailed investigation is to establish the irreversible failure of the functions of most of the brain, especially the cerebrum, cerebellum and brainstem. The guideline of the German Medical Association uses the term "irreversible brain function failure" instead of "brain death".

Two qualified doctors must independently detect brain death. Brain death diagnostics should only be performed by experienced and highly qualified doctors (intensive care, anesthetics, neurology or neurosurgery). At least one of the physicians should be a neurologist or neurosurgeon with many years of experience in the field of intensive care and brain death diagnostics.

The two doctors are not allowed to be involved in any organ donation that may follow, nor to accept instructions from the doctors involved.

The process of brain death detection is precisely regulated by a protocol and is done in three steps:

1. Are there any prerequisites for irreversible brain function failure?

First of all, it has to be determined whether there is enough brain damage at all. On the one hand, a distinction is made as to whether the brain is affected directly or only as the result of other damage (for example cardiac arrest). In addition, it examines where the damage is located in the brain. Roughly subdivided so-called supra- and infratentorial brain damage.

About the cerebellum is a connective tissue membrane, the "cerebellum tent" or Tentorium cerebelli. Supratentorial damage is above this membrane, infratentorial damage underneath. This subdivision is important for the further diagnostic procedure.

Helpful for this is a computed tomography (CT) of the brain. This imaging exam can detect massive damage to the brain. However, shortly after resuscitation or immediately after acute damage, the CT image may still appear normal. It must also be documented when this disease began or when the causative accident took place.

Even before the detailed brain death diagnosis can be initiated, other causes for the condition of the patient must be excluded. Other possible causes include poisoning, including medication or drugs, hypothermia or even shock. If necessary, the pain and / or anesthetic medication must be discontinued (for a sufficient amount of time).