Manual of Surgery by Alexis Thomson (book recommendations for young adults .TXT) 📖

Surgical Shock.—The condition known as surgical shock may be looked upon as a state of profound exhaustion of the mechanism that exists in the body for the transformation of energy. This mechanism consists of (1) the brain, which, through certain special centres, regulates all vital activity; (2) the adrenal glands, the secretion of which—adrenalin—acting as a stimulant of the sympathetic system, so controls the tone of the blood vessels as to maintain efficient oxidation of the tissues; and (3) the liver, which stores and delivers glycogen as it is required by the muscles, and in addition, deals with the by-products of metabolism.

Crile and his co-workers have shown that in surgical shock histological changes occur in the cells of the brain, the adrenals, and the liver, and that these are identical, whatever be the cause that leads to the exhaustion of the energy-transforming mechanism. These changes vary in degree, and range from slight alterations in the structure of the protoplasm to complete disorganisation of the cell elements.

The influences which contribute to bring about this form of exhaustion that we call shock are varied, and include such emotional states as fear, anxiety, or worry, physical injury and toxic infection, and the effects of these factors are augmented by anything that tends to lower the vitality, such as loss of blood, exposure, insufficient food, loss of sleep or antecedent illness.

Any one or any combination of these influences may cause shock, but the most potent, and the one which most concerns the surgeon, is physical injury, e.g., a severe accident or an operation (traumatic shock). This is usually associated with some emotional disturbance, such as fear or anxiety (emotional shock), or with hæmorrhage; and may be followed by septic infection (toxic shock).

The exaggerated afferent impulses reaching the brain as a result of trauma, inhibit the action of the nuclei in the region of the fourth ventricle and cerebellum which maintain the muscular tone, with the result that the muscular tone is diminished and there is a marked fall in the arterial blood pressure. The capillaries dilate—the blood stagnating in them and giving off its oxygen and transuding its fluid elements into the tissues—with the result that an insufficient quantity of oxygenated blood reaches the heart to enable it to maintain an efficient circulation. As the sarco-lactic acid liberated in the muscles is not oxygenated a condition of acidosis ensues.

The more highly the injured part is endowed with sensory nerves the more marked is the shock; a crush of the hand, for example, is attended with a more intense degree of shock than a correspondingly severe crush of the foot; and injuries of such specially innervated parts as the testis, the urethra, the face, or the spinal cord, are associated with severe degrees, as are also those of parts innervated from the sympathetic system, such as the abdominal or thoracic viscera. It is to be borne in mind that a state of general anæsthesia does not prevent injurious impulses reaching the brain and causing shock during an operation. If the main nerves of the part are “blocked” by injection of a local anæsthetic, however, the central nervous system is protected from these impulses.

While the aged frequently manifest but few signs of shock, they have a correspondingly feeble power of recovery; and while many young children suffer little, even after severe operations, others with much less cause succumb to shock.

When the injured person's mind is absorbed with other matters than his own condition,—as, for example, during the heat of a battle or in the excitement of a railway accident or a conflagration,—even severe injuries may be unattended by pain or shock at the time, although when the period of excitement is over, the severity of the shock is all the greater. The same thing is observed in persons injured while under the influence of alcohol.

Clinical Features.—The patient is in a state of prostration. He is roused from his condition of indifference with difficulty, but answers questions intelligently, if only in a whisper. The face is pale, beads of sweat stand out on the brow, the features are drawn, the eyes sunken, and the cheeks hollow. The lips and ears are pallid; the skin of the body of a greyish colour, cold, and clammy. The pulse is rapid, fluttering, and often all but imperceptible at the wrist; the respiration is irregular, shallow, and sighing; and the temperature may fall to 96° F. or even lower. The mouth is parched, and the patient complains of thirst. There is little sensibility to pain.

Except in very severe cases, shock tends towards recovery within a few hours, the reaction, as it is called, being often ushered in by vomiting. The colour improves; the pulse becomes full and bounding; the respiration deeper and more regular; the temperature rises to 100° F. or higher; and the patient begins to take notice of his surroundings. The condition of neurasthenia which sometimes follows an operation may be associated with the degenerative changes in nerve cells described by Crile.

In certain cases the symptoms of traumatic shock blend with those resulting from toxin absorption, and it is difficult to estimate the relative importance of the two factors in the causation of the condition. The conditions formerly known as “delayed shock” and “prostration with excitement” are now generally recognised to be due to toxæmia.

Question of Operating during Shock.—Most authorities agree that operations should only be undertaken during profound shock when they are imperatively demanded for the arrest of hæmorrhage, the prevention of infection of serous cavities, or for the relief of pain which is producing or intensifying the condition.

Prevention of Operation Shock.—In the preparation of a patient for operation, drastic purgation and prolonged fasting must be avoided, and about half an hour before a severe operation a pint of saline solution should be slowly introduced into the rectum; this is repeated, if necessary, during the operation, and at its conclusion. The operating-room must be warm—not less than 70° F.—and the patient should be wrapped in cotton wool and blankets, and surrounded by hot-bottles. All lotions used must be warm (100° F.); and the operation should be completed as speedily and as bloodlessly as possible. The element of fear may to some extent be eliminated by the preliminary administration of such drugs as scopolamin or morphin, and with a view to preventing the passage of exciting afferent impulses, Crile advocates “blocking” of the nerves by the injection of a 1 per cent. solution of novocaine into their substance on the proximal side of the field of operation. To prevent after-pain in abdominal wounds he recommends injecting the edges with quinine and urea hydrochlorate before suturing, the resulting anæsthesia lasting for twenty-four to forty-eight hours. To these preventive measures the term anoci-association has been applied. In selecting an anæsthetic, it may be borne in mind that chloroform lowers the blood pressure more than ether does, and that with spinal anæsthesia there is no lowering of the blood pressure.

Treatment.—A patient suffering from shock should be placed in the recumbent position, with the foot of the bed raised to facilitate the return circulation in the large veins, and so to increase the flow of blood to the brain. His bed should be placed near a large fire, and the patient himself surrounded by cotton wool and blankets and hot-bottles. If he has lost much blood, the limbs should be wrapped in cotton wool and firmly bandaged from below upwards, to conserve as much of the circulating blood as possible in the trunk and head. If the shock is moderate in degree, as soon as the patient has been put to bed, about a pint of saline solution should be introduced into the rectum, and 10 to 15 minims of adrenalin chloride (1 in 1000) may with advantage be added to the fluid. The injection should be repeated every two hours until the circulation is sufficiently restored. In severe cases, especially when associated with hæmorrhage, transfusion of whole blood from a compatible donor, is the most efficient means (Op. Surg., p. 37). Cardiac stimulants such as strychnin, digitalin, or strophanthin are contra-indicated in shock, as they merely exhaust the already impaired vaso-motor centre.

Artificial respiration may be useful in tiding a patient over the critical period of shock, especially at the end of a severe operation.

Failing this, the introduction of saline solution at a temperature of about 105° F. into a vein or into the subcutaneous tissue is useful where much blood has been lost (p. 276). Two or three pints may be injected into a vein, or smaller quantities under the skin.

Thirst is best met by giving small quantities of warm water by the mouth, or by the introduction of saline solution into the rectum. Ice only relieves thirst for a short time, and as it is liable to induce flatulence should be avoided, especially in abdominal cases. Dryness of the tongue may be relieved by swabbing the mouth with a mixture of glycerine and lemon juice.

If severe pain calls for the use of morphin, 1/120th grain of atropin should be added, or heroin alone may be given in doses of 1/24th to 1/12th grain.

Collapse is a clinical condition which comes on more insidiously than shock, and which does not attain its maximum degree of severity for several hours. It is met with in the course of severe illnesses, especially such as are associated with the loss of large quantities of fluid from the body—for example, by severe diarrhœa, notably in Asiatic cholera; by persistent vomiting; or by profuse sweating, as in some cases of heat-stroke. Severe degrees of collapse follow sudden and profuse loss of blood.

Collapse often follows upon shock—for example, in intestinal perforations, or after abdominal operations complicated by peritonitis, especially if there is vomiting, as in cases of obstruction high up in the intestine. The symptoms of collapse are aggravated if toxin absorption is superadded to the loss of fluid.

The clinical features of this condition are practically the same as those of shock; and it is treated on the same lines.

Fat Embolism.—After various injuries and operations, but especially such as implicate the marrow of long bones—for example, comminuted fractures, osteotomies, resections of joints, or the forcible correction of deformities—fluid fat may enter the circulation in variable quantity. In the vast majority of cases no ill effects follow, but when the quantity is large or when the absorption is long continued certain symptoms ensue, either immediately, or more frequently not for two or three days. These are mostly referable to the lungs and brain.

In the lung the fat collects in the minute blood vessels and produces venous congestion and œdema, and sometimes pneumonia. Dyspnœa, with cyanosis, a persistent cough and frothy or blood-stained sputum, a feeble pulse and low temperature, are the chief symptoms.

When the fat lodges in the capillaries of the brain, the pulse becomes small, rapid, and irregular, delirium followed by coma ensues, and the condition is usually rapidly fatal.

Fat is usually to be detected in the urine, even in mild cases.

The treatment consists in tiding the patient over the acute stage of his illness, until the fat is eliminated from the blood vessels.

Traumatic Asphyxia or Traumatic Cyanosis.—This term has been applied to a condition which results when the thorax is so forcibly compressed that respiration is mechanically arrested for several minutes. It has occurred from being crushed in a struggling crowd, or under a fall of masonry, and in machinery accidents. When the patient is released, the face and the neck as low down as the level of the clavicles present an intense coloration, varying from deep purple to blue-black. The affected area is sharply defined, and on close inspection the appearance is found to be due to the presence of countless minute reddish-blue or black spots, with small areas or streaks of normal skin