Coma

As with so many academic subjects, Susan began to perceive that the more she read about coma, the less she felt she knew. To her surprise, it was an enormous subject, spanning many disciplines of medical specialization. And perhaps the most frustrating of all was Susan’s realization that it was not known what determined consciousness, other than saying that the individual was not unconscious. The definition of one consisted of being the opposite of the other. Such a tautologous circle was a travesty of logic until Susan accepted the fact that medical science had not advanced enough to define consciousness precisely. In fact, being fully conscious and being totally unconscious (coma) seemed to represent opposite ends of a continuous spectrum which included partway states like confusion and stupor. Hence the inexact, unscientific terms were more an admission of ignorance than poorly conceived definitions.

Despite the semantics Susan was well aware of the stark difference between normal consciousness and coma. She had observed both states that very day in a patient ... Berman. And despite the lack of precision in definition, there was no lack of information regarding coma. Under the heading of “acute coma,” Susan began to fill page after page in her notebook with her characteristically small handwriting.

Her particular interest was in causation. Since science had not decided on what particular aspect of brain function had to be disrupted, Susan had to be content with precipitating factors. Being interested in acute coma, or coma of sudden onset, also helped to narrow the field but still was impressive and growing. Susan looked back over the list of causes that she had noted so far:

Trauma = concussion, contusion, or any type of stroke Hypoxia = low oxygen:

(1) mechanical

—strangulation

—blocked airway

—insufficient ventilation

(2) lung abnormality

—alveolar block

(3) vascular block

—blood cannot get to brain

(4) cellular block of oxygen use High Carbon Dioxide Hyper (hypo) Glycemia = high (low) blood sugar Acidosis = high acid in the blood

Uremia = kidney failure with high uric acid in the blood Hyper (hypo) Kalemia = high (low) potassium

Hyper (hypo) Natremia = high (low) sodium

Hepatic Failure = increase of toxins which would normally be detoxified by the liver

Addison’s Disease = severe endocrine or glandular abnormality Chemicals or Drugs ...

Susan took an extra couple of pages for the chemicals and drugs associated with acute coma and listed them alphabetically, each with a separate line to make it possible to add information as she got it: Alcohol

Insulin

Amphetamines

Iodine

Anesthetics Mercurial

diuretics

Anticonvulsants

Metaldehyde

Antihistamines

Methyl bromide

Aromatic hydrocarbons

Methyl chloride

Arsenic

Naphazoline

Barbiturates Naphthaline

Bromides

Opium

derivatives

Cannabis

Pentachlorophenol

Carbon disulfide

Phenol

Carbon monoxide

Salicylates

Carbon tetrachloride Sulfanilamide

Chloral hydrate

Sulfides

Cyanide

Tetrahydrozaline

Glutethimide Vitamin

D

Herbicides

Hypnotic

agents

Hydrocarbons

Susan knew that the list was not complete but nonetheless it gave her something to go on, something to keep in mind during her subsequent investigations, and it could be enlarged at any time.

Turning next to the general internal medicine textbooks, Susan opened the ponderous Principles of Internal Medicine and read the appropriate sections dealing with coma. The articles in Cecil and Loeb were about the same. Both books provided a rather good overview, although no new concepts were added. Several references were cited which Susan duly copied down in an ever-expanding list of necessary reading.

It felt good to get up and stretch. Susan allowed a deep comforting yawn. She wiggled her toes to try to encourage the blood to go there.

The cold draft along the floor had made her stir sooner than she might have otherwise. But once up she turned to the Index Medicus, the exhaustive listing of all articles published in all the medical journals.

Starting with the “most recent volumes and working backward, Susan searched for and extracted every article concerning acute coma and every article under the heading “Anesthetic complications: delayed return to consciousness.” By the time she had worked herself back to 1972, Susan had a list of thirty-seven prospective papers worth reading.

One title especially caught Susan’s attention: “Acute Coma at the Boston City Hospital: A Retrospective Statistical Study of Causes,”

Journal of the American Association of Emergency Room Physicians, volume 21, August 1974, pp. 401-3. She found the bound volume containing the article and was soon immersed in it, taking notes as she read.

Bellows had to call her by name before she looked up at him. He had come into the library, located her, and had taken the seat directly across from her. But she did not look up from her reading. Bellows had tried clearing his throat with absolutely no effect. It was as if Susan were in a trance.