Coma

Coma (Gk. koma, deep sleep), is a condition of unconsciousness occurring in certain forms of disease, which differs from sleep in that the patient cannot be aroused. In the slighter forms of coma the phenomena are closely allied to those of sleep; signs of deepening coma are the development of stertorous breathing, with puffing of the cheeks, the involuntary passage of the evacuations, and impairment of reflex movements. Death, if it occurs, is usually preceded by marked changes in the character of the pulse and respiratory movements, in some instances by considerable rise of temperature. Coma may supervene upon injuries to the brain produced by violence, or resulting from disease within the cranium. The sudden onset of coma usually points to a vascular lesion. Epilepsy is one of the most common causes of the development of the comatose condition. Again, coma may occur in fevers, and may be produced by certain narcotic poisons (especially opium (q.v.) and alcohol), or by the accumulation of morbid poisons within the animal body, as in the condition known as uraemia, or in diabetes. The diagnosis of the cause of coma is oftentimes fraught with extreme difficulty. In many instances the most carefully conducted examination of the patient fails to warrant any definite conclusion, and time alone can be expected to reveal the cause of the mischief. There may be evidence of some head injury, or poisoning may be suspected, in which case the stomach pump must be employed; the existence of paralysis may throw light on the matter, and the ophthalmoscope and stethoscope, and in some instances an examination of the urine, may clear up the diagnosis. The greatest caution, however, is necessary in drawing conclusions, even in cases where any data can be discovered to start from. The treatment of coma depends mainly upon its cause, and is, therefore, obviously beyond the scope of the present article.