Elements of Surgery

by Robert Liston

Swelling is caused by the enlarged and overloaded vessels relieving themselves by effusion of part of their contents into the surrounding cellular texture. The effusion varies in extent and consistence, according to the degree of inflammatory action, and the species of resistance offered; at first it is serous, then mixed with fibrin, and consequently spontaneously coagulable. Cæteris paribus, the greater the resistance, the less the effusion, and the more violent the inflammatory action; the chance of its speedy and favourable termination is also more diminished. Even the enlargement of the bloodvessels produces a certain degree of intumescence previous to effusion. The relief to the vessels by effusion giving rise to swelling, when it occurs in loose cellular tissues, may be considered as a beneficent provision of nature. But in vital organs it may be productive of the most serious consequences; as in these, very slight effusion will often endanger the structure of the organ, destroy its functions, and not unfrequently be attended with fatal consequences.

The nature of the effused fluid varies according to the degree of violence and advancement of the action, and is also modified by the texture in which that action occurs. It may consist of serum, lymph, blood, or pus. In inflammation, in short, exhalation, though at first diminished, is soon much increased, whilst the powers of the absorbent vessels are diminished, or at least do not maintain their usual relation to those of the exhalants.

Pain is the next symptom enumerated. Here the very common error of supposing that where there is pain there must always be inflammation may be noticed. Some diseases attended with the most acute pain, as Tic Douloureux and Cramp, are generally unattended with inflammation. Many chronic diseases, too, are accompanied with violent and long-continued paroxysms of pain, without excited circulation of the part.

This erroneous opinion often gives rise to highly prejudicial proceedings, as—the exhausting, by copious depletions, the vital powers of patients, already enfeebled by continued disease or treatment—the consequent aggravation of the urgent symptoms—and, the then only termination of the disease and of the practice, death.

Again, it is true that we must bleed, in some cases, with the view of preventing the occurrence of inflammation; yet the prophylactic treatment may be carried too far, as in cases of violent injuries, or after severe operations. In these instances, the immediate abstraction of blood, so far from being beneficial, expedites the dissolution of the patient, or at least greatly retards the cure. Pains arising from local irritations are often treated in a similar way, whilst the removal of the cause would be much more likely to restore the natural action of the parts.

Though inflammation does not always accompany the sensation of pain, yet the latter, in a greater or less degree, attends inflammatory action; and, perhaps, it is fortunate that it does so. Because, were it not for the occurrence of pain, the patient’s attention would not be directed to the disease; he would continue to use the part as if in health, and the affection would thus be much aggravated. Whereas, according to the existing provision of nature, pain is felt at the commencement of the action, the presence of which the patient is thereby made aware of; and he is compelled to employ such measures for its removal as reason naturally dictates, of which none is more effectual than disusing the affected part. The nerves are thus the safeguards of the various parts of the body in health—their nurses in disease. A part deprived of sensation may be used, even to the destruction of its texture, without producing any impression on the sensorium, and consequently without the animal being conscious of it.

The presence of pain, as a symptom of inflammation, may be easily explained. The connexion of the vascular with the nervous system is very constant and intimate. Their ramifications accompany each other, and are contained in the same cellular sheath; and without the reciprocal influence of each, neither could perform its functions perfectly. By injecting a limb soon after its separation from an animal, and before its vital heat has departed, spasms of all muscles are sometimes produced; showing the intimate connexion between these two systems. This, however, is distinct from the contractions of the muscular fibre produced by the application of stimuli. In the former case, the contractions are universal, and induced through the medium of the nerves. In the latter, the irritability of the fibre is excited.

When the circulation is excited, the nerves accompanying the affected vessels are unusually compressed, and over-stimulated by the circulating fluid, in which, probably, some change takes place, and in this manner unnatural impressions are produced; the nerves themselves are likewise the seat of disease, in consequence of the enlargement of the minute capillaries which permeate them. Over-distension of the coats of the vessels may also be supposed to give rise to painful feelings, independently of any affection of the accompanying nervous trunks.

The degree of pain is generally in proportion to the sensibility of the part when in health; it also depends upon the distensibility of the parts affected, and on the intensity of the inflammatory action. When bones, tendons, &c., which in their uninflamed state are nearly insensible, become inflamed, the pain and suffering are most excruciating, owing to the resistance opposed to the dilatation of the vessels, and the prevention of the effusion by which they naturally relieve themselves.

The kind of pain also varies, in consequence of different modifications in the action causing different impressions on the sensorium. Pain is not always increased in proportion to the natural sensibility of the part; for in some instances the sensibility is rendered much more intense, while in others it is much obtunded.[1]