Synonyms:—Pyelonephritis is sometimes designated as pyelonephrosis, pyonephritis, or pyonephrosis.
Definition:—Pathologically there is a plain difference between pyelitis and pyelonephritis, although they are usually considered together by most writers. Pyelitis is distinctly a condition of suppuration of the mucous lining of the pelvis of the kidney, a purulent inflammation of this membrane. It may be primary, resulting from cold or injury, but it is more apt to occur from the presence of calculi or renal sand in the pelvis. It usually proceeds from some inflammation of the bladder, which extends upward through the ureters. One writer claims that in fifty-four per cent of his cases of gonorrhea there was pyelitis. This does not argue well for his treatment of the primary disease.
On the other hand pyelonephritis is a conjoined involvement of the structure of the kidney with the inflammation of the mucous lining of the pelvis. It is seldom if ever primary, resulting from other inflammatory conditions of the kidneys. It extends downward and involves the pelvic membranes in purulent inflammation. An abscess within the structure of the kidney may involve in the contiguous inflammation a considerable portion of that organ, and pouring its discharges into the pelvis may cause direct purulent infection there.
The presence of this condition may be inferred when upon urinary analysis it will be observed that there are marked changes in the secretory and excretory function of the kidney, determined by the presence or absence, or by deficiency or excess of the normal urinary constituents. With pyelitis, there should be but little interference with the normal functional operations of the kidneys.
It is not impossible that pyelonephritis may be caused by an involvement of the contiguous renal structure from previous purulent inflammation of the pelvic membrane extending upward. A symptomatic distinction of these two conditions is by no means plain, and for that reason they are usually described together. The term pyonephrosis, strictly speaking, should apply only to a condition when from a blocking of the ureters pus accumulates in the kidney pelvis, producing distention or rupture.
Etiology:—With the causes named, such as the presence of irritating renal calculi or the extension of infectious inflammatory disease, this condition of purulent inflammation may also be caused by the decomposition of retained urine in the pelvis of the kidney, from obstruction of the ureters, or from retention of urine in the bladder. There may be occlusion of the ureters, or there may be external compression from foreign growths; parasites may induce the condition, or it may be caused by the ingestion of irritating diuretics or irritating remedies which must necessarily be eliminated by the kidneys. It results also from the previous existence of the infectious fevers. It may follow chronic disease of the bladder or enlarged prostate, or urethral stricture. I am convinced that the condition sometimes occurs late in life from the existence of paraplegia, or from any cause which will induce general relaxation with paralysis of the vesicle sphincter. A distinct diphtheritic inflammation of the pelvis of the kidney has been diagnosed with the formation of a characteristic diphtheritic membrane, inducing serious, usually fatal, infection.
Symptomatology:—The presence of pus in the urine by no means presupposes the existence of this disease. Purulent disease of the urethra, bladder, prostate gland and ureters must be excluded. In the absence of symptoms of disease of these parts, pus in the urine in whatever quantity, with soreness in the region of the kidneys and other evidence of local disorder, will suggest the condition. With soreness there is often continuous renal pain, which may be increased by sneezing or coughing or by a sudden jar of the body. The pain may be localized or it may extend around the body, producing a sickening sensation, with slight nausea, or it may extend downward into the thigh, or into the testicle of the affected side. As stated, with pyelitis alone, there will be but little change in the condition of the urine. It will contain some pus cells, and with pus albumin is always present in the pus serum, and consequently is present in the urine. When the condition is acute in character, there is but little pus or albumin. In chronic cases the pus may become enormous in quantity and may be mixed with blood corpuscles or with considerable blood.
In pyelonephritis there is considerable renal debris in the urine, and usually a marked alteration in the character of the fluid. The quantity of urine is often increased, due perhaps to increased compensatory activity of the glomeruli, or to some compensatory dilatation of the healthy portion of the organ. It is also true that when one kidney only is affected, as is usually the case, there is increased functional activity of the unaffected organ. There is but little mucus or epithelium present, except it comes from the bladder. Occasionally a pus coagulum or other plug will temporarily obstruct the ureter on the diseased side, when the urine will flow clear and normal for a short time from the healthy organ. At this time there is apt to be increased pain on the diseased side, although the pain is usually by no means as severe as in renal calculi. This is followed by the escape of a greatly increased quantity of pus. This combination of symptoms is prima facie evidence of the involvement of but one organ.
There is usually erratic fever, frequently of hectic type; more rarely there are distinct intermissions; occasionally there are regularly recurring remissions, so closely resembling malarial manifestations as to be classed with that condition. It may resemble the fever of tuberculosis in all of its characteristics. This septic fever results ultimately in emaciation, prostration and anemia; or the fever may assume a typhoid type, sometimes running as high as 104° F., to be followed by profuse perspiration and increased weakness. Sometimes marked heart weakness, mental dulness, delirium or stupor occur. There is absence, however, of tympanites, diarrhea and rose spots.
When in chronic cases obstruction of the urethra becomes more or less permanent, a distinct pyonephrosis exists, which results in a bulging and fluctuating tumor in the region of the kidney, which is with difficulty distinguished from perinephric abscess, except by a sudden outpour of a large quantity of pus and a disappearance of the pain and tumor upon the escape of the plug.
Diagnosis:—A diagnosis of this disease when pus is present is not difficult if purulent disease of the bladder and urethra may be excluded. The local pain and tenderness, with the presence of pus, are strong diagnostic factors. In differentiating between pyelitis and cystitis it must be remembered that in the latter disease the urine is ammoniacal and there is an abundance of epithelial scales, while in the former condition the urine is acid and the pain may be localized in one or both kidneys. When catheterization of the ureters is practicable, the diagnosis is positive. A cysto-scopic examination of the bladder will determine the presence or absence of disease of that organ. The sudden occurrence of extreme pain in the ureter or in the kidney is diagnostic of obstruction and is usually attributed to a calculus. When the obstruction has escaped, as is announced by the disappearance of the pain and a quantity of pus is found in the urine, the condition is apparent. It is with difficulty that a distinction is made between pyelonephrosis and perinephric abscess, the bulging tumor above described being present in both cases. In perinephric abscess the tumor may be present without the extreme pain of obstruction of the ureter, and the urine may contain no pus. In the former case when pus appears in the urine the tumor is not found. The existence of pyelocystitis—the simultaneous occurrence of pyelitis and cystitis—is sometimes difficult to determine. The local pain may be depended upon to assist in the diagnosis.
Prognosis:—Uncomplicated pyelitis is quite amenable to treatment, and a favorable prognosis may be usually made. When pyelonephritis is present, or when from the accumulation of pus there is distention of the pelvic sac, with obstruction of the tubules, as in pyelonephrosis, the condition is serious, a fatal result often occurring. Pyelitis resulting from other diseases is apt to be temporary, often abating rapidly during convalescence and only occasionally becoming chronic. Cases which occur as the result of calculi are usually chronic and more or less intractable. Pus forming during the progress of tubercular nephritis need not necessarily be pronounced an incurable condition, as tuberculosis of the kidney will abate under favorable circumstances with good treatment, the pus becoming encysted and coagulated, or caseated.
Treatment:—I am positive that good results obtain from the persistent treatment of the fever, although it is plain that the temperature results from infection. I would prescribe aconite in small doses persistently, and although no malaria is apt to be present, I should give quinin in broken doses during the intermissions and occasionally during marked remissions, unless it seemed to induce or increase irritation of the bladder. No depression from the aconite need be anticipated. On the other hand, I believe that in small doses frequently repeated it sustains the heart action. To assure this result it may be combined with cactus to excellent advantage. If there is a large quantity of pus escaping with the urine, irrigation of the bladder is of service, whether there be cystitis or not. If cystitis is diagnosed, it must invariably receive the most positive and thorough treatment, as there will be no permanent results from the treatment of the pyelitis unless this condition be overcome. The same statement may be made concerning old standing gonorrhea or prostatitis. If it were possible to irrigate the pelvis of the kidney with warm water or with a warm permanganate solution, more speedy results could be obtained. This must be accomplished, if at all, by insisting upon the patient drinking large quantities of water, either hot or cold, or taking freely of mild infusions of the soothing diuretics, as epigea, marshmallows, stigmata maydis or triticum. Good results are also obtained from gelsemium and hydrangea. When there is no prostration, these may be given in full doses for an extended period. When the disease is caused by calculi, the treatment should be conducted after the plan suggested in nephrolithiasis. At no time, however, should irritating diuretics be administered or harsh or severe measure be adopted. The use of dry cups over the kidneys will yield better results, than hot applications alone. I have obtained excellent results from the use of the tincture of iron alternated every two hours with gallic acid, in the early stages of the acute form of this disease. I have given it indiscriminately under all circumstances with no cause for regret. I would impress upon the prescriber the importance of antagonizing the formation of pus by constitutional measures, and would suggest the administration of echinacea or calcium sulphid or calcium or potassium iodid during the entire course of the disease, watching, however, for any local irritation from the potassium salt.
The diet should be nutritious, easily digestible and of plain, non-irritating articles. The coarse vegetables, especially asparagus, which is irritating to the kidneys, should be excluded. The patient should take but little salt or other condiments, especially those which are stimulating in character. Milk alone may be administered during the active period of the disease, and if the urine is alkaline whey and buttermilk may be given. Alcoholic stimulants must be sedulously avoided.
Other remedies which control pus formation in the urinary tract are chimaphila, thuja, pichi and urotropin. These may in certain cases be selected and administered according to the indications, with directly beneficial results.
The Eclectic Practice of Medicine with especial reference to the Treatment of Disease, 1910, was written by Finley Ellingwood, M.D.