DROPS - KIDNEY DISEASE The association of dropsy with kidney disease is of such frequent occurrence that it is often difficult to convince both patients and phy sicians that "Bright's disease" can exist when dropsy is absent.
If we go through the list of diseases of the kidney we find that their association with dropsy is as follows : Acute congestion of the kidney—no dropsy.
Chronic congestion of the kidney—dropsy according to the condition of the heart.
Acute cmd chronic degeneration of the kidney—no dropsy.
Acute exudative nephritis—subcutaneous dropsy, most frequent with nephritis caused by scarlet fever, or by exposure to cold. A similar subcutaneous oedema can be produced by scarlet fever or by exposure to cold without nephritis.
Acute productive (or diffuse) nephritis—both subcutaneous dropsy and dropsy of the serous cavities.
Chronic nephritis with exudation—dropsy of the subcutaneous con nective tissue and of the serous cavities in nearly every case.
Chronic nephritis without exudation—no dropsy until late in the disease unless from complicating lesions.
Suppression of urine from obstruction of the ureters—no dropsy.
The primitive explanation of renal dropsy was that fluids accu mulated in the body because the patient passed too little water. This seemed satisfactory even to so good an observer as Bartels. It has always had its effect on therapeutics; the rule has been, if a patient has dropsy make him pass more urine. This explanation, however, is in constant contradiction with clinical experience.
The present condition of our knowledge on this subject may be stated somewhat as follows : 1. All dropsies are due to an increased transudation of blood serum from the capillaries and a diminished absorption by the lymphatics. The increased transudation is the more important part of the process.
2. Inflammatory dropsies (or exudations) and passive dropsies may be produced in one of two ways : (a) The capillaries act as filters. The blood serum within them follows the laws of exosmosis. Either increased pressure or a change in the composition of the serum can cause an increased tran sudation through the walls of the capillaries.
(b) The capillaries with their endothelium act as glands and se crete serum. Changes in the composition of the blood or irritating substances in the surrounding tissues can irritate the endothelium and cause increased secretion.
Following these rules the probable explanations of renal dropsies are: 1. In acute exudative nephritis the dropsy is due to inflammatory changes in the skin. The dropsy is regularly confined to the subcu taneous connective tissue, and is especially frequent when the ne phritis is caused by scarlet fever, or by exposure to cold.
2. In acute productive nephritis and in chronic nephritis with exu dation the dropsy involves both the subcutaneous connective tissue and the serous cavities. It may be due to irritating substances in the
blood, to changes in the composition of the blood, or to changes in blood pressure.
3. In chronic nephritis without exudation, the dropsy which comes on late in the disease is caused by changes in blood pressure due to heart failure.
Scattered through medical literature are reports of cases of gen eral subcutaneous dropsy coming on suddenly, lasting for a short time, without any evidence of renal or other disease, and terminating in recovery. Traube thinks that such dropsies are due to a disturb ante of the functions of the skin caused by exposure to the weather, but this explanation will not answer for all the cases. In some pa tients (Taylor, Medical Times and Gazette, 1871) the dropsy was pre ceded by a well-marked febrile movement. I know of only one case of this kind which terminated fatally. It is reported by Wernicke (Dezdsches Archiv ftir klinische Medicin, VI., 622). The patient, a girl twenty-two years old, died apparently from the dropsy, and the autopsy showed no lesion to account for the symptoms. The follow ing case is an example of this form of dropsy : Male, 26, admitted to the Roosevelt Hospital on April 17th, 1884. He had been perfectly well and working hard until two months ago. Then he began to have cough, mucous sputa, and wheezing breathing. One month ago he developed general subcutaneous oedema; the urine was somewhat diminished in quantity, but the man did not feel sick. When admitted to the hospital his pulse was 96, temperature 98° F., respiration 30. There was very marked general subcutaneous oedema. The skin and mucous membranes were rather pale, but the man was well-nourished and did not feel at all sick. A soft systolic murmur could be heard at the apex and base of the heart; the action of the heart was somewhat intermittent and irregular. The dropsy increased for a few days and then gradually diminished. The record of the urine was as follows : By May 1st the dropsy had entirely disappeared and the man was apparently well.
I have seen a number of hospital patients, who unquestionably had kidney disease, but who had attacks of subcutanous oedema after exposure, apparently not connected with their kidney disease, but caused by inflammation of the skin.
The ordinary treatment of dropsy is directed to the removal of the serum after it has transuded from the vessels. We try to get rid of the dropsy by sweating, by diuresis, or by purging. It is evident that a much more satisfactory treatment would be to prevent the tran sudation. If we could find remedies to destroy the irritating sub stances in the blood and tissues which cause the blood serum to tran sude, we would be able to prevent the dropsy instead of having to get rid of it.