Definition:—A condition in which serum albumin is found in the urine.
When the application of heat and nitric acid will reveal the presence of albumin in the urine, the condition is a pathological one. Albumin which may be supposed to be present, and is discoverable only by the careful use of delicate chemical tests, need have no attention.
Etiology:—The causes may be of two kinds: First, those conditions which produce some change in the minute structure of the kidney, by which the proper excretion is not performed and the albumin and serum globulin are permitted to escape; second, those conditions elsewhere within the system which act upon the heart or upon the circulation of the blood, either directly or through the central nervous system, and induce changes in blood pressure.
There may be, then, renal congestion, acute or chronic, active or passive; there may be acute or chronic nephritis; there may be conditions of toxemia, resulting from the influence of the specific poisons or from diphtheria, scarlet fever and other infectious diseases; blood changes which result from the influence of poisoning, and constitutional diseases, such as syphilis, scrofula, scurvy and leukemia. The presence of albumin during the progress of protracted tevers and during epilepsy or apoplexy is due largely to the changed conditions of blood pressure during the influence of the disease upon the circulatory apparatus. The presence of albumin after violent muscular exercise is due to the same condition, under entirely different circumstances. Pregnancy obstructs the circulation and influences the blood pressure within the kidneys.
The occurrence of albumin, associated with blood or pus, in the urine is by no means true albuminuria, as this albumin is precipitated directly from the serum of the blood or pus, and has not been separated in the functional operation of the renal epithelium. It is not impossible, however, that albumin may be so excreted and blood or pus be thrown into the urine in addition. It is difficult or well nigh impossible to determine the existence of both conditions at the same time.
A condition known as cyclic albuminuria, sometimes called paroxysmal albuminuria, is that in which the albumin appears at a regular time; it may be once or twice each day, of it may be on every second or third day. The albumin may appear regularly after each meal, or it may occur only after one meal, the same meal each day. It may be present while the patient is up and around during the day, and may be absent when in a recumbent position. The patient may be indulging in regular severe physical or mental exercise, which induces the presence of albumin at a given time each day. Under these circumstances there is usually at first no other change in the condition of the urine, and there is but a small quantity of albumin. At other times albumin may appear in the urine after the taking of certain kinds of food, notably eggs, cheese, and highly seasoned food.
It has been my observation, where there is a sensitiveness to the conditions which induce the presence of albumin in the urine, that there is likely to be later in life some slowly developing change in the kidney structure, tending toward some form of chronic nephritis, which may ultimately be fully established.
Usually the quantity of albumin present depends upon the severity of the underlying condition or the intensity of the exciting cause. A notable exception, however, to this is in the case of chronic interstitial nephritic—the small red kidney or the contracting kidney, which is found late in life, usually after fifty-five years of age.
Disease of the heart, either acute or chronic, or circulatory conditions extreme in character, induced by the action of heart or circulatory stimulants, will cause the appearance of considerable quantity of albumin in the urine at certain times.
Symptomatology:—There are no symptoms independent of those of the underlying disease which will suggest the presence of albumin in the urine. Familiarity with the causes of this condition will suggest to the physician the necessity for an examination of the urine.
Diagnosis:—The determination of the presence of albumin in the urine is by no means difficult. There are certain simple infallible tests, to which we may readily resort. The presence of a sediment in the urine has no significance in determining the presence of albumin unless it be plainly that of blood or pus. A uric acid or phosphatic sediment or a sediment of the urates does not indicate the presence of albumin. The substance is more frequently present in clear, normally colored urine, with a specific gravity at or above the normal point. The albumin found in interstitial nephritis at that stage of the disease when there is an excretion of a very large amount of the watery constituents of the urine, is present in very small quantity in colorless urine of low specific gravity.
When albumin is present from parenchymatous nephritis during early middle life, the urine is usually of high specific gravity, of clear, deep amber color, and the albumin is present in large quantity. It will precipitate upon the addition of the proper tests in a clear, white mass.
In preparing urine for the test, a specimen should be selected which is taken from the total quantity of urine voided in twenty-four hours, which has been collected in a perfectly clean vessel and kept in a cool place. The urine should be filtered, to separate it from all morphologic con-stitutents and render it perfectly clear. The specific gravity and color and reaction should be noted. A test tube should be filled one-half full of urine, and heat should be applied at the top by a slight inclination of the tube. When boiled, there will be white, cloudy discoloration of the boiled portion of the urine, more or less dense in proportion to the amount of the precipitated substance. This cloud is composed either of phosphates, carbonates or of albumin. The addition of a few drops only of full-strength nitric acid will cause this cloud to become deeper and to break up into fragmentary particles or flakes, if it is albumin; if the cloud is composed of phosphates, it will immediately disappear without effervescence, and the urine become clear and usually darker in tint; if of the carbonates, it will clear up with effervescence. If it clears up, but with only slight effervescence, it is composed both of the carbonates and phosphates. The boiling of the top portion of the urine in the tube permits of a comparison to be made between the boiled urine and the natural urine.
This test for urine I have come to rely upon as the most practical of all of the tests for constant bedside use.
Heller's test, sometimes known also as the German test, requires considerable care and close observation. Into a clean test tube pour half of a dram of pure nitric acid. Allow one, two or three drops of the suspected urine to run down the side of the inclined tube. It will not mix with the acid, but will float on the top. The action of the acid upon the coloring matter of the urine and upon its crystalline constituents will cause a stratum of a deep clear color to form on the top of the acid from the urine. This will vary in different cases, and if urea be present in excess, crystals may form. If albumin be present, a clear white zone is formed at the point of contact between the urine and the acid. This will disappear upon the addition of heat, as all albumin will dissolve in full strength nitric acid if heated.
The picric acid test of Johnson consists of adding a few drops of the saturated solution of picric acid to the urine, when a white albuminous cloud will be formed at the junction of the two fluids. There are several other tests which can be found in all works upon this subject, which may be studied with reference to confirming the presence of albumin suggested bv these tests, or of determining the approximate quantity of albumin present. These need not be given here.
Prognosis:—The presence of albumin in the urine is always regarded as serious. Until recently it has long been the custom of careless physicians to put a short limit upon the life of the patient if albumin was discovered. It is now known that in those conditions where albumin is present without structural chance of the kidneys the condition may be relieved by proper treatment and the albumin may permanently disappear from the urine. Where organic disease is present, the condition is always serious. The acute cases taken in hand promptly and treated according to modern methods are amenable to treatment. When the condition is due to disease of other organs, the prognosis depends upon the amenability of that disease to treatment.
Treatment:—In all cases the blood pressure should be regulated. If there is an undue strain upon the heart, this must be relieved: if there is a high degree of nervous tension, sedatives must be administered. The bromids, gelsemium and cimicifuga answer the purpose with me in more cases than any other single remedies. I have found it a good plan, when the specific gravity of the urine is constantly high, with a precipitation of the urates or phosphates, or with an excess of urea in the urine (and I have found albumin present under these circumstances very many times) to reduce the specific gravity of the urine and to regulate the quantity of these substances by a regulation of the diet and by proper constitutional treatment. Usually I exclude all alcoholics and tobacco, as well as tea and coffee, and insist upon the patient drinking freely of water between meals to the extent of from two to four quarts during each day. Milk only is drunk at meal time. I then put the patient on a strict non-nitrogenous diet and give him a grain of potassium acetate every two hours with a minim each of specific macrotys and gelsemium. Often the albumin disappears with the reduction of the specific gravity of the urine. I have observed albumin present with a greasy appearance of the urine in fleshy patients of plethoric habit, where there was fault of digestion, especially where I had reason to suspect an imperfect digestion of fats. The albumin disappears when the conditions are corrected.
Attention to the diet in all cases is important. The course advised above is usually applicable for a short period. The patient may then be allowed to eat sparingly of meat, and later to eat eggs freely and drink an abundance of skimmed milk. In some cases of chronic kidney disease I have persisted in the use of eggs as the principle article of diet with good results, care being taken that the albumin of the eggs was properly digested. Tea, coffee and tobacco should be allowed only, in the judgment of the physician. The patient must form a habit of drinking more freely of water, and in the largest quantities, after the food is digested, and in time to permit it to pass from the stomach before the next meal. It is of advantage to these patients to drink a full quantity of water, either hot or cold as they may choose, before they arise in the morning, lying quietly on the right side from half of an hour to an hour after its ingestion.