Coma | Causes, Diagnosis, Treatment and Management of Coma

Coma is the most severe state of impaired consciousness.

It is a state of “unarousable psychological unresponsiveness in which the subjects lie with eyes closed they show no psychologically understandable response to external stimulus or inner need”.
Coma may vary in degree and in its deepest stages no reaction of any kind is obtained; corneal, pupillary, pharyngeal, tendon and plantar reflexes are all absent.
With lesser degrees of coma, pupillary reactions, reflex eye movements are preserved,
When the term “semi-coma” is used, it refers to that state when an individual responds to a painful stimulus by groaning, opening the eyes or with irregular respirations.
Despite the clear descriptions of coma, quantification is difficult. So Glasgow coma scale is almost universally used for this purpose. This measure must be charted from time to time while the patient is under obstruction.

Glasgow coma scale

Eye opening (E)

Best motor response (M)

Obeys	6
Localizes	5
Withdraws (flexion)	4
abnormal flexion positioning	3
Extension	2
Nil	1

Verbal response (V)

Brainstem lesions- infarction, hemorrhage, encephalitis, abscess, meningitis, bacterial toxemia, tumor, trauma, neurosurgical intervention.
Cerebral hemisphere lesion with edema and secondary compression of brainstem- infarction, trauma, hemorrhage, hydrocephalus, hypertensive encephalopathy, status epilepticus, cerebral malaria.
Metabolic abnormalities- diabetes mellitus (hyperglycemia), hypoglycemia, hepatic failure, renal failure, respiratory failure, cardiac failure, hyponatremia, hypokalemia, hypoxia, hypothyroidism.
Drugs and physical agents- anesthetic agents, drug overdose and alcohol ingestion, hypothermia and hyperthermia.

Urine- for sugar, albumin and acetone.
Blood- blood count, estimation of blood glucose, electrolyte level, serum calcium, blood urea level, blood nitrogen level, blood levels of common intoxicants, blood smear for malaria parasite and blood culture.
Cerebrospinal fluid- for evidence of hemorrhage, meningitis or encephalitis.
Analysis of vomit or gastric lavage.
X-ray skull for evidence of any fracture to show erosion of sells which would suggest increased intra-cranial pressure, infection of sinuses.
Chest X-ray may reveal carcinoma (metastasis), bronchiectasis, abscess, cerebral embolism.
CT-scan or MRI-
Coma with focal signs or evidence of head injury-whether focal signs indicate a brainstem or supratentorial lesion. A normal scan may be seen in patients with hypoglycemia or hepatic coma.
Coma without focal signs but with meningeal irritation- brain imaging for subarachoid hemorrhage.
Cerebral angiography- useful aid in brain tumor and sub-dural hematoma.
EEG- may provide evidence of sub-clinical epilepsy.

Removal or control of cause- e.g. gastric lavage and diuretics in narcotic poisoning.
Ensure proper respiration- oxygen inhalation, respiratory stimulants like doxapram if needed. When there is deep coma; secretions and vomiting if inhaled into lungs, will soon result in death. The patient must be nursed in the semi-prone or lateral position with frequent changes from one side to the other.
Ensure proper circulation- parentral fluids intravenous glucose or blood transfusion, vasopressor drug like dopamine of low blood pressure or shock.
Care of bowels and bladder- indwelling catheter, saline or soap water enema.
Care of skin- frequent change of position in bed, alcohol or spirit rub and powdering of skin and care of mouth.
Control of secondary infection with antibiotics especially in presence of fever.
Neurosurgical intervention- if coma progression raises the possibility of herniation.

Related Topics