The coma ( ancient Greek κῶμα , 'deep sleep' ) is a long-term complete loss of consciousness . In medicine, a full coma is the most severe form of a quantitative disturbance of consciousness in which a patient can not be awakened even by strong external stimuli , such as repeated pain stimuli. If this condition is not fully developed, it is called sopor (pre-coma).
The coma is a symptom (sign of illness) and not a disease. In the international classification of health disorders (ICD-10) it was therefore classified under the heading “R” (symptoms and findings) (R40.2). The coma is an expression of a severe disturbance of the cerebral function and is usually life-threatening. The further development ( prognosis ) of the comatose depends on the underlying disease and medical care.
Primary brain diseases
Stroke (vascular blockage or bleeding)
- Sudden event, coma predominantly with brain stem damage
- Cerebral haemorrhage can lead to unconsciousness if it damages the brain stem directly or via a general increase in pressure in the skull.
traumatic brain injury
- Coma especially with brain stem damage
Meningitis / encephalitis
- inflammatory disease, usually with a high fever
- Development of a coma, usually over hours
- sudden event, usually spontaneous recovery
- slow development - coma mostly due to increased intracranial pressure
Metabolic disorder - metabolic coma
- Sugar metabolism disorder
- Lack of oxygen ( hypoxia , hypoxemia ) or excess CO 2 in the blood ( hypercapnia )
- with oxygen uptake disorders (respiratory tract, lungs)
- with circulatory failure (after a few seconds)
- Renal insufficiency (uraemic coma, coma uraemicum )
- Hepatic insufficiency (hepatic coma)
- other metabolic causes (congenital metabolic disorders, etc.)
- hormonal causes ( pituitary insufficiency , adrenal insufficiency , myxedema coma , etc.)
- as an accident (accidental)
- from drugs (e.g. alcohol, intoxicants)
- medically desirable ( sedation , anesthesia , "artificial coma")
The classification is based on clinical criteria, i.e. according to the reaction to certain stimuli. Depending on the classification used, a distinction is usually made between three to four grades:
- Degree - targeted defense against pain, pupil movement intact, eye movement when the organ of equilibrium is irritated ( vestibulo-ocular reflex ) intact
- Degree - non-directed defense against pain, mass movements, external squint ( divergent eyeballs )
- Grade - no defense, only flight reflexes, vestibulo-ocular reflex missing, pupil reaction weakened
- Degree - no pain reaction, no pupillary reaction, failure of further protective reflexes
Established in emergency medicine is the Glasgow Coma Scale - which is also used as a decision-making aid e.g. B. is used for ventilation. It also includes minor disorders of consciousness.
"Artificial coma", "artificial deep sleep"
These terms, which are mainly used in the media, describe a drug-induced decrease in consciousness that is reversible after the drug has been discontinued. The use of the term coma should therefore be avoided here, as coma in the medical sense describes an unregulated loss of consciousness. The terms sedation or long-term anesthesia are more appropriate . Sedation is a controlled state. For this purpose, patients who are anesthetized in difficult phases of intensive treatment are given drugs in dose-dependent doses. Medicines with different effects are used, mostly in combination: sedatives and sleeping pills ( sedatives , hypnotics , such as benzodiazepines or propofol ), pain relievers ( opioid analgesics ), other narcotics and psychotropic drugs . Even ventilated patients are sometimes not kept in deep anesthesia all the time, if possible only sedated (see Richmond Agitation Sedation Scale ).
Through observation, patient surveys and technical monitoring and examination methods, the picture has become more and more differentiated as to which performance of the brain is reduced during anesthesia, especially long-term anesthesia: alertness ( vigilance ), stress , sensation of pain , fear , motor reaction, memory. Most of the drugs used influence several brain functions, with varying degrees of emphasis.
There are not only differences from drug to drug, but also in the effect of the same drug on different patients. For example, a well-sedated but not at all comatose patient can cooperate in treatment measures without remembering anything afterwards ( amnesia ), a patient lying in bed motionless and without signs of vegetative stress can remember numerous details afterwards, and a third patient can still remember numerous details despite high doses - and painkillers may not be responsive, but their motor skills are restless.
This is severe brain damage in which the function of the cerebrum is severely impaired, partially failed or even completely extinguished. Therefore it is also called "apallic syndrome" ("without cerebral cortex"). The life functions are - as is usually the case - maintained by the brain stem , but the patients do not become conscious due to a lack of cognitive functions. As a result, those affected wake up, but can neither actively nor passively come into contact with the environment. Technically, the vegetative state is called persistent vegetative status (PVS).
As long as the cerebrum is not too badly damaged, coma patients have a good prognosis of waking up again. The same is reported again and again around the world. However, as with a normal coma, the period of time can vary widely: from a few days to several years. The process can be considerably supported by suitable rehabilitation measures , especially if the person affected is already showing signs of regression of the coma.
- Manfred Stöhr, Thomas Brandt, Karl Max Einhäupl : Neurological Syndromes in Intensive Care Medicine . Kohlhammer, Stuttgart 1998, ISBN 3-17-014557-6 .
- Wolfgang J. Bock , Christel Bienstein : Unconscious, a challenge for relatives, carers and doctors . 2nd Edition. Self-determined life, Düsseldorf 1994, ISBN 3-910095-20-8 .
- Katharina Kluin: Days in a coma . In: stern . Born in 2014, No. 5 , January 23, 2014, p. 78–83 (Six people tell of their time in a coma and of their awakening from it, including the writer Kathrin Schmidt ).
- Hugo van Aken : Intensive Care Medicine . Georg Thieme , Stuttgart / New York 2007, ISBN 978-3-13-114872-8 ( limited preview in the Google book search [accessed on May 27, 2016]).
- Ulrike Herrmann : Only in deep sleep. In: the daily newspaper , January 16, 2009.
- Hans-Walter Striebel: Analgesic sedation in (ventilated) intensive care patients . In: Hans-Walter Striebel (Ed.): Operative Intensive Care Medicine . Schattauer , Stuttgart / New York 2007, ISBN 978-3-7945-2480-8 , pp. 6 ( limited preview in Google Book search).