Elements of Surgery

by Robert Liston

In unhealthy pus, such as already noticed, or in vitiated muco-puriform secretion, the colour and consistence are different, and flakes, resembling portions of lymph, are seen floating in it: they consist of fibrin thrown off with the pus, instead of being used for reparation and bounding the extent of the abscess; and by this latter circumstance such fluid is distinguished from the pure or laudable pus. In purulent matter also, especially that of an unhealthy character, the existence of a quantity of sulphureted hydrogen is indicated by the blackening of silver probes, and of various substances applied to the sore. It is necessary to bear in mind, that a matter resembling pus in many particulars, but in reality differing essentially from it, has generally been regarded as true purulent fluid; for it results, from some observations of Mr. Gulliver, that the pulpy matter, so frequently found in the substance of fibrinous clots of the heart and veins, is simply fibrin which has coagulated and passed into the state of softening, which he regards as a very frequent elementary disease. The subject is one of great interest, because it is connected with the theory of suppuration, and tends to modify materially our views on the pathology of the veins.

The symptoms attendant on suppuration vary much according to the nature of the parts involved. In general, it is accompanied with the subsidence of acute pain and fever; but, in unyielding textures, the increase of swelling, by the formation of purulent matter, is often attended with an aggravation of the symptoms, and with an increase of danger to the structures affected. The pain which accompanies suppuration is dull, and attended with a sensation of fulness and throbbing, and an increase of the tumour; ultimately the parietes of the abscess become absorbed, and the collection, being more superficial, the most careless observer must be convinced of its existence, by the less equivocal signs of fluctuation and pointing. In general, especially when the abscess is deeply seated, a greater or less degree of œdema surrounds it, producing a soft pitting tumour; but not unfrequently, when the degree of excitement is more intense, lymph, instead of serum, is effused, rendering the part more hard and resisting: in such cases it may be difficult to discover the existence of purulent matter, and the tactus eruditus, as it is called, will be found of material service; for, though pus is neither acrid nor corroding, still, if allowed to remain for any long period, much mischief may be caused—the bones may become diseased—muscles and tendons may slough—and the matter may discharge itself, by means of ulceration, into certain cavities and canals, and produce very serious consequences. Of the bad effects produced by the pressure and irritation of extensive and undisturbed collections of purulent matter, every practitioner must have seen numerous examples. Still, through prejudice, erroneously conceived opinions, or servile imitation, the greatest dread seems, with many, to exist of the practice of giving a free exit to the contents of such depôts.

The symptoms and sensible signs of suppuration are usually preceded by shivering, recurring at intervals, and commonly terminating in profuse perspiration. But this is by no means an unequivocal sign of the occurrence of suppuration; and this process very often takes place without any feeling of rigor.

The older authors supposed that pus was derived from the solids—or that it was formed by the melting of dead animal matter—or that it was the result of putrefaction; in accordance with which latter opinion, the term pus was given to the fluid; but such opinions have long since been justly exploded. Pus is generally supposed to be separated from the blood by the secreting power of the bloodvessels of an exposed and inflamed part, in consequence of their having assumed a new mode of action. The secretion from exposed surfaces is not at first purulent, but is transparent, serous in fact, and is somewhat of a gelatinous appearance; and it is only, it is said, after exposure to the atmosphere for some time, and when drying, that it presents the appearance of globules. Pus is often formed where the secreting surface has not been exposed to the air; on opening an abscess, the parietes of which had been previously entire and not much attenuated, purulent matter of the usual properties is discharged. It has been asserted that pus globules may be formed independently of any vital action; and that, if the serous fluid be removed immediately after its secretion by a granular surface, and kept in a temperature similar to that of the inflamed part, and be at the same time freely exposed to the air, globules will appear in as short a period as when the secretion is allowed to remain in contact with the sore. Some have also supposed that the mere admission of air into the cellular substance causes suppuration; but this is far from being correct. In chronic purulent depôts, however, the admission of air, by favouring putrefaction probably, often produces most serious results; other causes are generally in operation at the same time, as will be afterwards more fully explained.

Pus was formerly regarded as irritating and corroding, and was therefore carefully removed from every granulating sore; but purulent matter, though it may prove a source of irritation to the neighbouring parts, does not disturb the surface which secretes it, but, on the contrary, protects the tender granulations, and acts as a temporary cuticle. A crust is formed by the evaporation of the thinner part of the fluid; and we frequently see small sores healing rapidly when thus protected. In some instances, we adopt the hint given to us by nature, and produce a scab by the application of powders, lunar caustic, &c.

The discharge does not always consist of laudable purulent matter. Pus formed in the diseased part itself has particular characters, according to the tissue involved; thin and greyish in bones, opaque and caseiform in cellular tissue, flocculent in serous, and greenish and thready in mucous membranes; it is said to be reddish in the liver, and yellowish-grey in muscles. Its sensible properties are various, often very offensive when proceeding from a cavity containing decayed bones, and it degenerates in consequence of disturbance of the constitution, or of the part affected. It is also frequently suppressed, in consequence of over-action in the vessels of the part, or from debility, partial or general.

Suppression of a purulent discharge is to be regarded as an untoward symptom, fraught with considerable danger, being generally followed by the most violent constitutional disturbance. Certain cases would seem to warrant the belief that a species of metastasis occurs; that the matter is absorbed, and again deposited in some other part, perhaps of the utmost importance in the animal economy. The danger arising, when the pus is not separated from the blood, has already been adverted to. No wonder, if from any cause it does not escape by its accustomed channel, that an effort should be made to deposit it somewhere else, for the temporary relief of the system. The most vascular parts are commonly chosen, as the lungs, spleen, and liver. In the cavities of joints, also, matter is often found in great quantities. This is sometimes indicated by the occurrence of tenderness and swelling for only a short period previously; but, in other cases, its presence has never been suspected. In purulent collections, after wounds from accident or operation, on the suspension of the discharge, the patient becomes affected with severe constitutional irritation, and gradually sinks; the existence of purulent depôts in the viscera of the chest or abdomen, being perhaps not indicated by any, unless very equivocal, symptoms, and these appearing only a short time before dissolution. A late writer has endeavoured to connect this with inflammation of the veins; but such an opinion is not borne out by observation, although the two circumstances may occasionally coexist. In many cases the veins of a limb are found filled with pus, yet their coats present no marks of inflammatory action having existed in them. Their mouths are open in the wound, from failure of that healthy action by which they would have been closed by coagulated lymph, and the matter appears to be taken up by them as secreted.

From the discharge varying according to the state of the system, the latter can in general be accurately ascertained by examination of the sores which afflict the patient.

In collections of matter not far removed from the surface, the most superficial, and generally the most dependent, portion of the parietes appears inflamed; its inner surface is gradually absorbed; and, when it has thus become attenuated, a portion of the integument sloughs or ulcerates. A communication is established with the diseased parts, through the external surface, thus providing an aperture for the evacuation of the matter—of extraneous substances—or of parts of the body which have either mortified, or otherwise become useless to the system. In such collections, more especially if deeply seated, the matter generally seeks the surface, or extends in the course of the bloodvessels.

Cold abscesses, as they are called, often contain as much flaky fibrinous matter as true pus: hence one of the signs of inflammation, swelling, is absent; the fibrin being discharged instead of having been added to the neighbouring parts.