XXVIII. Special Diseases.
Heat Stroke.
Synonyms:—Sunstroke; thermic fever; insolation; heat prostration; coup de soleil.
Definition:—A condition of acute disorder of the nervous system, resulting from exposure to excessive heat.
Etiology:—The condition may be induced by prolonged exposure to the direct rays of the sun on a hot day, sunstroke, or it may be due to confinement in a hot, poorly ventilated room, heat stroke or thermic fever. Individuals working in the streets of a city, or teamsters, outdoor carpenters, stone masons and hod carriers, soldiers, those engaged in out of door activities, or other individuals who are continuously exposed to the hot sun, are subject to sunstroke. Those who work in blast furnaces, engineers, stokers, cooks and bakers are among those who are affected by heat stroke.
Those who are addicted to habits of dissipation, and especially beer drinkers, are liable to this condition. There is no doubt that it occurs more readily where there is imperfect metabolism, or imperfect elimination, as autointoxication renders the individual more liable to attacks. This may have previously existed, or it may develop from the rapid formation of toxins from the heat, or the two conditions may be combined. Those laborers who are careless of their habits, and who are filthy as well as intemperate are directly influenced under circumstances where the temperature ranges from 85° to 95° or 100° with a considerable humidity of the atmosphere. Those who are fatigued from overwork or from mental exhaustion, or who suffer from excitement or nervous irritation and irritability, and especially those who have had a previous attack of heat stroke, are all prone to the influence of heat.
The direct influence of the excessive heat upon the heat centers, where elimination and heat radiation is temporarily suspended, is the immediate cause of the disorder. One of two conditions may exist: either the heat centers may be paralyzed, with loss of inhibiting power, in which case thermic fever is induced, or the vasomotor nerves may be paralyzed, in which case exhaustion follows, with normal or subnormal temperature and profuse sweating.
Symptomatology:—Usually in sunstroke the individual complains of discomfort from the excessive heat for a considerable period before any real symptoms appear. There is dizziness, a strong disinclination to further physical exercise, weakness and oppression. These symptoms being overlooked and the patient continuing in the sun as before, is suddenly attacked with a violent headache; he falls to the ground and soon becomes unconscious. The face becomes very red or livid, and later cyanotic; the blood vessels of the head and neck are all distended, and often there is a violent convulsion; there is difficulty in breathing and the breathing soon becomes stertorous, or it may be rapid and shallow. The temperature rises rapidly to perhaps 110° or 112° F.; the pulse may reach 160, though usually it is from 125 to 140. The pupils first become contracted; as paralysis advances they become dilated.
In other cases the patient falls unconscious, but may be partially aroused. He complains of a headache, or holds the head with his hands; he is conscious of a difficulty of breathing and shows signs of much distress. Later delirium develops which may assume a wild or excitable type; the skin is hot and dry, and the urine is suppressed. The temperature in these cases may not exceed 105° or 106° F. Later the stupor increases to coma, the pulse becomes very rapid, and the Cheyne-Stokes respiration is observed. There may be incontinence of both the urine and the feces.
In yet other cases the patient complains for several days of being oppressed by the protracted heat; he does not sleep day nor night; is restless, suffers from extreme headache and disordered digestion with colicky pains; there is vertigo and chromatopsia or blurred vision. There is little if any perspiration, the skin continuing dry; there is urinary irritation with but a small quantity of water passed. Under these circumstances, when the stroke comes it is apt to be more severe.
In heat prostration the symptoms are those of profound asthenia or of acute development; there is dizziness, nausea, faintness, more or less severe headache with drowsiness, and some chilliness. The temperature falls, the skin becomes cold and clammy, the face is very pale, and prostration is plainly apparent. The temperature may fall from one to three degrees below normal at first, although later it may rise to two degrees above normal.
Diagnosis:—The fact that the patient is laboring in a heated atmosphere and that the attack is sudden, with other conspicuous symptoms which have been named, suggest the condition. It must be distinguished from apoplexy, from alcoholic intoxication, from uremic intoxication, and from some forms of meningeal trouble.
Prognosis:—Unless the sudden unconsciousness is extremely severe at once, the prognosis is usually favorable, although it requires a considerable period of care and attention to restore perfect health. Patients who have been once overcome by heat never recover their power to resist heat, and are subsequently subject to unpleasant symptoms, often when the heat is but little increased. The direct rays of the sun with these patients sometimes produces unpleasant symptoms.
Treatment:—The treatment of an acute attack of this disorder must be vigorous and energetic; the patient must be taken to a cool place, stripped of his clothing, and every effort made to reduce the temperature of the body. Usually the head is packed with ice, an ice bag is applied to the spine, and cool water is poured over the surface of the body. However, I am confident that if the body be exposed to the air, and the surface of the body with the face and neck be sponged with hot water, and then thoroughly fanned, that a more rapid reduction of heat occurs; elimination is immediately favored. I am also confident that a prompt restoration of the elimination is nearly as essential as the reduction of heat, and this is not favored by the use of cold alone. There is an extreme tendency toward determination of blood in the nerve centers, and this the application of cold favors also. Heat will materially assist in equalizing the temperature, attracting it to the surface of the body. Moist heat on the body surface promotes dissipation of heat also; a gentle flagillation of the skin of the extremities with the flat of the hand and an upward rubbing to promote the venous circulation is of much importance. Where unconsciousness exists, it is well to wrap the feet and legs in blankets wrung from hot mustard water. The temperature should be watched with the thermometer in the rectum, and as it approach a manageable point the extreme activity of the efforts at restoration may be suspended.
Hypodermic injections of strychnin and atropin are sometimes of good advantage. If the heart is failing, digitalis may be injected in proper quantity. An active physic is sometimes administered in these cases to advantage, as a thorough evacuation of the bowels is of considerable service. Following this the patient should have an enema of the normal salt solution.
It is seldom that medicine can be given by the mouth during the period of unconsciousness. Belladonna is indicated, and the carbonate or the chlorid of ammonium may be beneficial, but the usual sedatives will not act with sufficient promptness until after consciousness is restored. At this time, the patient being put to bed and properly cared for, and the temperature not above 102.5° or 103° F., gelsemium and aconite in moderate doses may be given every hour; or if nervous excitement is intense, small and repeated doses of the bromids may be given. Where there are evidences of cerebral congestion, continuing after reaction has occurred, it is well to give medium doses of ergot, or ergot and a bromid, or hydrobromic acid, to control delirium, but more especially to prevent the development of a possible secondary meningitis. It will be necessary to give the patient the very best of care and treatment for several days. He should be kept in bed, and every possible cause of excitement or worry should be excluded. Other symptoms may appear, which should be treated in accordance with their specific indications.
Patients who work out of doors, under the hot sun, should be educated, if possible, in measures which conduce to warding off attacks. It is useless to caution those addicted to the use of alcohol of the danger of indulgence while working in the sun or in a hot place. Individuals readily impressed by heat, should avoid excitement or violent exercise in high temperatures; should live temperate lives, and should especially pay the closest attention to elimination, seeing to it that there is no constipation and that the skin is kept active by frequent bathing. They should eat light but sufficient food, and should see to it that their places of occupation are well ventilated. When exposed to heat, if there are symptoms of fulness in the head, or vertigo, or nausea, or faintness, during the continuance of the work, the work should be immediately suspended, the patient should lie down in a cool place, should bathe the head in cool water, and should keep very quiet.
Those working in the sun will obtain much benefit by frequently wetting the hair in cool water, or by keeping a handkerchief or a fold or two of wet blotting paper in the hat.
