Chronic pyelonephritis is a chronic nonspecific bacterial inflammation that occurs mainly with the involvement of interstitial kidney tissue and cup-pelvic complexes. It is manifested by malaise, dull lower back pain, subfebrility, dysuric symptoms. In the process of diagnosis, laboratory tests of urine and blood, ultrasound of the kidneys, retrograde pyelography, scintigraphy are carried out. Treatment consists in following a diet and a gentle regime, prescribing antimicrobial therapy, nitrofurans, vitamins, physiotherapy.
ICD 10
N11 Chronic tubulointerstitial nephritis
Meaning
In nephrology and urology, chronic pyelonephritis accounts for 60-65% of cases of all inflammatory pathology of the genitourinary organs. In 20-30% of cases, chronic inflammation is the outcome of acute pyelonephritis. Pathology mainly develops in girls and women, which is associated with morpho-functional features of the female urethra, facilitating the penetration of microorganisms into the bladder and kidneys. The disease is more often bilateral in nature, but the degree of kidney damage may vary.
The course of chronic pyelonephritis is characterized by alternating periods of exacerbation and subsiding (remission) of the pathological process. Therefore, polymorphic changes are simultaneously detected in the kidneys – foci of inflammation in various stages, scarring areas, areas of unchanged parenchyma. The involvement of new areas of functioning renal tissue in inflammation causes its death and the development of chronic renal failure (CRF).
Causes
The etiological factor causing chronic pyelonephritis is microbial flora. These are mainly colibacillar bacteria (paracystic and Escherichia coli), enterococci, proteus, Staphylococci, Pseudomonas aeruginosa, Streptococci and their microbial associations. A special role in the development of the disease is played by L-forms of bacteria formed as a result of ineffective antimicrobial therapy and changes in the pH of the medium. Such microorganisms are characterized by resistance to therapy, difficulty of identification, the ability to persist for a long time in the interstitial tissue and become active under the influence of certain conditions.
- In most cases, chronic pyelonephritis is preceded by an acute attack. There are cases of combination of pyelonephritis with chronic glomerulonephritis. Chronic inflammation is promoted by:
- untreated violations of urine outflow caused by kidney stones, ureteral stricture, vesicoureteral reflux, nephroptosis, prostate adenoma;
- other bacterial processes in the body (urethritis, prostatitis, cystitis, cholecystitis, appendicitis, enterocolitis, tonsillitis, otitis, sinusitis, etc.);
- general somatic diseases (diabetes mellitus, obesity), conditions of chronic immunodeficiency and intoxication.
In young women, the onset of sexual activity, pregnancy or childbirth may be the impetus for the development of chronic pyelonephritis. In young children, the disease is often associated with congenital anomalies (ureterocele, diverticula of the bladder) that violate urodynamics.
Classification
Chronic pyelonephritis is characterized by the course of three stages of inflammation in the renal tissue.
- At stage I, leukocyte infiltration of the interstitial tissue of the medulla and atrophy of the collecting tubules are detected; the renal glomeruli are intact.
- At the II stage of the inflammatory process, scar-sclerotic lesion of the interstitial and tubules is noted, which is accompanied by the death of the terminal sections of the nephrons and compression of the tubules. At the same time, hyalinization and desolation of the glomeruli, narrowing or obliteration of blood vessels develop.
- In the final, III stage, the renal tissue is replaced by scar tissue, the kidney has a reduced size, looks wrinkled with a bumpy surface.
According to the activity of inflammatory processes in the renal tissue in the development of chronic pyelonephritis, phases of active inflammation, latent inflammation, remission (clinical recovery) are distinguished. Under the influence of treatment or in its absence, the active phase is replaced by a latent phase, which, in turn, can go into remission or again into active inflammation. The remission phase is characterized by the absence of clinical signs of the disease and changes in urine tests. According to clinical development, there are erased (latent), recurrent, hypertensive, anemic, azotemic forms of pathology.
Symptoms
The latent form of the disease is characterized by scant clinical manifestations. Patients are usually concerned about general malaise, fatigue, subfebrility, headache. Urinary syndrome (dysuria, lower back pain, edema), as a rule, is absent. Pasternatsky’s symptom may be weakly positive. There is a slight proteinuria, intermittent leukocyturia, bacteriuria. Violation of the concentration function of the kidneys is manifested by hypostenuria and polyuria. In some patients, minor anemia and moderate hypertension may be detected.
The recurrent variant of chronic pyelonephritis proceeds in waves with periodic activation and subsiding of inflammation. The manifestations of this clinical form are severity and aching pain in the lower back, dysuric disorders, periodic feverish states. In the acute phase, a clinic of typical acute pyelonephritis develops. With progression, a hypertensive or anemic syndrome may develop. In the laboratory, especially with exacerbation, pronounced proteinuria, permanent leukocyturia, cylindruria and bacteriuria, sometimes hematuria, are determined.
In the hypertensive form, the hypertensive syndrome becomes predominant. Arterial hypertension is accompanied by dizziness, headaches, hypertensive crises, sleep disorders, shortness of breath, and heart pain. Hypertension is often malignant in nature. Urinary syndrome, as a rule, is not pronounced or has an intermittent course. The anemic variant of the disease is characterized by the development of hypochromic anemia. The hypertensive syndrome is not pronounced, the urinary syndrome is unstable and meager. The azotemic form combines cases when the disease is detected only at the stage of CRF. Clinical and laboratory data of the azotemic form are similar to those of uremia.
Diagnostics
The difficulty of diagnosing chronic pyelonephritis is due to the variety of clinical variants of the disease and its possible latent course. Diagnostic tactics include:
- Urine test. In the general analysis of urine, leukocyturia, proteinuria, and cylindruria are detected. Urine examination by the Addis-Kakovsky method is characterized by the predominance of leukocytes over other elements of the urinary sediment. Bacteriological urine culture contributes to the detection of bacteriuria, identification of pathogens of chronic pyelonephritis and their sensitivity to antimicrobial drugs. To assess the functional state of the kidneys, samples of Zimnitsky, Rehberg, biochemical blood and urine tests are used.
- Blood test. Hypochromic anemia, acceleration of ESR, neutrophilic leukocytosis are detected in the blood.
- Instrumental research. The degree of renal dysfunction is clarified by chromocystoscopy, excretory and retrograde urography, nephroscintigraphy. A decrease in the size of the kidneys and structural changes in the renal tissue are detected by ultrasound, MRI and CT of the kidneys. Instrumental methods objectively indicate a decrease in kidney size, deformation of cup-pelvic structures, a decrease in secretory kidney function.
- Kidney biopsy. In clinically unclear cases of chronic pyelonephritis, a kidney biopsy is indicated. Meanwhile, sampling of unaffected renal tissue during biopsy may give a false negative result during morphological examination of the biopsy.
In the process of differential diagnosis, kidney amyloidosis, chronic glomerulonephritis, hypertension, diabetic glomerulosclerosis are excluded.
Treatment
Patients are shown to observe a gentle regime with the exception of factors that provoke exacerbation (hypothermia, colds). Adequate therapy of all intercurrent diseases, periodic monitoring of urine tests, dynamic observation of a nephrologist is necessary.
Diet
Dietary recommendations include avoiding spicy dishes, spices, coffee, alcoholic beverages, fish and meat dishes. The diet should be fortified, containing dairy products, vegetable dishes, fruits, boiled fish and meat. It is necessary to consume at least 1.5–2 liters of liquid per day in order to prevent excessive concentration of urine and ensure flushing of the urinary tract. With exacerbations of chronic pyelonephritis and with its hypertensive form, restrictions are imposed on the intake of table salt. Cranberry juice, watermelons, pumpkin, melons are useful.
Conservative therapy
Exacerbation requires the appointment of antibacterial therapy taking into account the microbial flora (penicillins, cephalosporins, aminoglycosides, fluoroquinolones) in combination with nitrofurans (furazolidone, nitrofurantoin) or nalidixic acid preparations. Systemic chemotherapy continues until the termination of bacteriuria according to laboratory results.
Vitamins B, A, C are used in complex drug therapy; antihistamines (mebhydroline, promethazine, chloropyramine). In the hypertensive form, hypotensive and antispasmodic drugs are prescribed; in the anemic form, iron preparations, vitamin B12, folic acid are prescribed.
Of the physiotherapeutic techniques, SMT therapy, galvanization, electrophoresis, ultrasound, sodium chloride baths, etc. have proven themselves especially well. In case of uremia, hemodialysis is required.
Surgical treatment
Advanced chronic pyelonephritis, which is not amenable to conservative treatment and is accompanied by unilateral renal shrinkage, arterial hypertension, is the basis for nephrectomy.
Prognosis and prevention
With a latent chronic variant of inflammation, patients remain able to work for a long time. In other forms, the ability to work is sharply reduced or lost. The timing of the development of chronic renal failure is variable and depends on the clinical variant of chronic pyelonephritis, the frequency of exacerbations, the degree of renal dysfunction. The death of the patient may occur from uremia, acute disorders of cerebral circulation (hemorrhagic and ischemic stroke), heart failure.
Prevention consists in timely and active therapy of acute urinary infections (urethritis, cystitis, acute pyelonephritis), rehabilitation of foci of infection (chronic tonsillitis, sinusitis, cholecystitis, etc.); elimination of local urodynamic disorders (removal of stones, dissection of strictures, etc.); correction of immunity.
