A system of practical medicine. By American authors. Vol. 4

by Unknown

Calculi of various kinds, sizes, and shapes may be found in the pelvis of the kidney. They are most frequently composed of uric acid, which may exist alone or with layers of phosphates superimposed. They are usually in concentric layers, more or less irregular in shape, and of a reddish-brown color of various shades. Soft concretions of urates are occasionally noted. Oxalate of lime is the material of many small calculi, and may be the nucleus of a larger one or occur in alternate layers with uric acid. These stones are of a dark grayish-brown and are exceedingly rough and irritating. Among the most frequent constituents of renal calculi are to be found phosphates, either of lime or the triple salt of ammonia and magnesia. They may form layers with other material, or constitute alone the largest and most curiously shaped of all the renal calculi. Their surface may be smooth and almost polished, or roughened, eroded, and almost crystalline in texture.

Cystine rarely forms a renal calculus, and xanthic oxide still more rarely. Masses of fibrin resulting from renal hemorrhage are described. They are said to be of the consistency of wax, tough and elastic. Coagula of the ordinary form may also give rise to the same set of symptoms. On one occasion the writer saw the dilated pelvis of the kidney filled with hundreds of spherical brownish soft masses from the size of a mustard-seed to that of a pea, easily crushed in the fingers, burning with the smell of albumen, and leaving but a small amount of ash.

The size of renal calculi may vary from almost microscopic grains, which then usually take the collective name of sand or gravel, and are most commonly composed of uric acid, up to masses of some ounces in weight, completely filling a dilated pelvis.

It is doubtful in what way renal calculi originate, their constituents being always present in the urine, but rarely crystallizing out. The uric-acid infarction of new-born children can hardly be considered as accounting for any large number of cases, although it might be the basis of calculi in young children. The uric and phosphatic deposits sometimes found in the tubes of the more mature kidney may possibly, when dislodged, be a point upon which additional quantities of the same substances are deposited, but anything which delays in the pelvis or in some of its calices a concentrated urine, especially if much mucus be present, may be regarded as favoring the agglomeration of deposits. A previous pyelitis is perhaps the usual cause of phosphatic deposits. Small uric-acid calculi may sometimes be found in considerable numbers in the sulcus surrounding some of the papillæ, and of a size which could hardly afford any marked symptoms in passing down the ureter. These, if any inflammation were to arise, would form a mass with pus or mucus which might serve as a nucleus for a phosphatic calculus. These suppositions are, however, rather theoretical and fragmentary, and do not cover all the cases. Constitutional predisposition has been much discussed, though not a great deal is known about it. A gouty tendency, however, undoubtedly favors the production of uric-acid calculi.

A small renal calculus, when formed, may be the beginning of several quite different sets of phenomena. Of these, the simplest and most favorable event is its descent through the ureter into the bladder, with its subsequent expulsion with the jet of urine from the urethra. If the calculus be small and smooth, the passage through the ureter may be attended with little or no uneasiness, but if it is large enough to fill or distend the tube, and especially if the stone be irregular and rough, its descent gives rise to excessively severe symptoms. These are pain in the back at the level of the kidney, in the side and groin corresponding to the ureter affected, sometimes shooting down the thigh; with retraction of the testicle; usually no fever, but much general depression; feeble pulse, coldness and paleness of the surface, fainting, and vomiting. The beginning of the attack is usually sudden, corresponding to the entrance of the calculus into the ureter, and the pain continues without intermission, though with some remissions, until its discharge into the bladder. The pain is usually of the severest, and is described as cutting or tearing in character. It is probable that an attack may sometimes end by the calculus, which has become engaged in the ureter, falling back into the pelvis instead of advancing through the ureter. In this case the pain ceases for the time, to be perhaps subsequently renewed, or, if the stone grow larger, so that it cannot re-enter the ureter, giving place to the symptoms due to irritation of the pelvis.

The urine is usually diminished in amount until the arrival of the calculus at the bladder, when the fluid that has been retained is suddenly discharged with the stone. Constant attempts to pass water during the passage downward of the calculus are the consequence of sympathetic irritation of the bladder, and not of accumulation of urine therein. The urine is likely to be bloody, but is not necessarily so. The smoothness or roughness of the surface of the stone is of much importance as determining the presence of this symptom.

The DIAGNOSIS of renal colic is usually not difficult, but it may not always be readily distinguished from hepatic or intestinal colic. The suddenness of the attack and intensity of the pain, its location in the side and downward to the groin, will in most cases make the condition very characteristic.

From hepatic colic or the passage of a gall-stone the situation of the pain, which is in the latter affection naturally somewhat farther forward, the tenderness on pressure in the same region, and often the whitish color of the stools or the presence of jaundice, as well as the history of former attacks, will usually make the distinction a matter of a high degree of probability.

Intestinal colic is usually referred to the middle of the abdomen, is accompanied by constipation, while the movements of the intestines and of flatus are often distinctly perceived by the sensation of the patient or the ears of the bystanders, and on the whole the attack is less severe and the pain less intense.

As has already been stated, it is probable that symptoms closely resembling if not identical with those of the passage of a calculus may occur when the substantial cause of them does not make its appearance; and although many of these may perhaps be accounted for by the ill-success of the search or by the calculus having ceased to pursue its downward course and having become quiescent in the kidney, yet it is well for the practitioner to be prepared for an occasional disappointment in obtaining tangible proof of the nature of the attack. Time may be required to decide whether an attack is due to calculus, or is simply one of the spasmodic or neuralgic paroxysms mentioned above.