The name “pyelonephritis” comes from the ancient Greek roots “pyelos” (trough, tub, vessel) and “nephros” (kidney); with the addition of the suffix “-itis”, the diagnosis literally means “inflammation of the renal pelvis”.
Indeed, pyelonephritis is any infectious and inflammatory process in the kidneys that affects mainly the renal pelvis, as well as the excretory calyces and interstitial tissue that open into it (a loose connective tissue base, or stroma, which fills the space between parenchymal, functional cells of organs). For more information about the structure of the kidneys, see the article “Kidneys. Norm and pathology” .
Pyelonephritis is one of the most common diagnoses in nephrology and urology; according to modern estimates, the cumulative share of acute and chronic pyelonephritis is 60-70% in the total flow of calls to specialists of this profile. In all age categories, except for the oldest, for a number of reasons outlined below, there is a significant, up to 5-8 times, predominance of females; in the elderly and presenile age, the statistical disproportion levels off, and in old age, men predominate among patients.
Absolute incidence rates are difficult to obtain. Firstly, not all patients consider it necessary to seek help with asymptomatic and asymptomatic forms (and in vain, since advanced pyelonephritis is fraught with very serious complications, up to renal abscess, sepsis, severe renal failure, etc.). Secondly, very often (over 80% of cases) pyelonephritis itself is a complication of a more general infectious or somatic disease, and is recorded as an additional, concomitant diagnosis. Thirdly, in vivo diagnosis of pyelonephritis in some cases is a difficult problem, in particular, due to pathomorphosis, i.e. changes in a typical clinic over decades: today, the symptoms of an acute period are often non-specific. Comparing the statistics of post-mortem studies (pyelonephritis is found in 8-10% of autopsies, and twice as often among those who died in old age, and most cases were not diagnosed during life) with outpatient and inpatient medical statistics, a number of authors naturally come to the conclusion that up to 80% of pyelonephritis remain unrecognized, and the proportion of misdiagnosis reaches 30-50%. It should be noted that this trend is global.
The English-language Wikipedia cites alarming data, assessing the prevalence of nephritis in general (not only pyelonephritis, but also glomerulonephritis , and autoimmune inflammation of the kidneys): people of African or Asian origin are most susceptible to this group of diseases (50-55%), followed by Hispanics (43%) , Caucasians and their descendants (17%).
Averaging of epidemiological estimates published in the literature indicates that about 1% of the world’s population falls ill with pyelonephritis every year, i.e. approximately 72 million people, of which about a million are in the Russian Federation. In the total volume of recorded urogenital infections, more than half (53%) is chronic pyelonephritis, 13-14% is acute pyelonephritis.
The reasons
Pyelonephritis is a bacterial infectious and inflammatory process. The possible role of viruses is also being studied, however, the vast majority of pyelonephritis detected today is caused by bacteria, primarily Esherihia coli (Escherichia coli), then by staphylococcus and other pathogenic cultures, which, when the process becomes chronic, often form a polymicrobial infection. There are various ways of penetration of the pathogen into the kidneys, in particular, with the blood or lymph flow, but hemato- and lymphogenous infection in this case is rare (about 5%). The two most significant factors that determine the onset and development of pyelonephritis are a) urogenital infections with subsequent ascending spread and b) stasis, urinary stasis.
The first of these factors, i.e. ascending infections of the urogenital tract, is the cause of the predominance of females among patients in early childhood, adolescence, and adulthood. The anatomical structure of the female body (short straight urethra, proximity of the anus to the exit of the urethra, a very high probability of introducing foreign pathogenic and opportunistic flora with the onset of sexual activity and each change of partner) makes it much more vulnerable to bacterial invasions of this kind – which reflects the above statistics. In addition, purely female risk factors include pregnancy and childbirth (changes in the tone of the urinary tract, mechanical compression of the ureters by the uterus). There is evidence that over the past two to three decades, cases of pyelonephritis in pregnant women have become five times more frequent – which, however,
The second global factor contributing to the penetration of infection into the renal pelvis are any conditions, diseases and pathological processes that impede the passage of urine. This explains the leveling of gender differences in morbidity as we approach the elderly and senile age: a significant percentage of benign (prostate adenoma) and malignant tumors, chronic urethritis and prostatitis, age-related decrease in elasticity and contractile activity of muscle fibers that provide peristalsis and urodynamics – all this is largely degree increases the likelihood of developing pyelonephritis in men.
In addition, universal risk factors are: urolithiasis and other diseases associated with urinary tract obstruction; hypovitaminosis; diabetes; tuberculosis; any conditions and conditions leading to a weakening of the immune system (hypothermia, overwork, the presence of foci of chronic infection in other body systems, surgical interventions, etc.).
Returning to the question of the bacterial nature of pyelonephritis, it should be noted that in 15% of cases it is not possible to identify the pathogen.
Symptoms
Existing classifications of pyelonephritis distinguish many of its varieties, which differ in the type and phase of the course, severity, clinical manifestations, etc.
In general, acute pyelonephritis is characterized by a rapid increase in body temperature (up to 39-40) with a corresponding general condition – hyperhidrosis, weakness, headache, often with nausea, vomiting and loss of appetite. Many patients report muscle and joint pain, cloudy and foul-smelling urine, and occasionally urinary disorders. Pain syndrome, sensitivity to percussion are localized in the lumbar region.
In old age and during pregnancy, acute pyelonephritis can manifest itself relatively mildly, with a predominance of general intoxication symptoms.
Relatively rare dangerous forms include acute purulent pyelonephritis and necrotizing papillitis, which can be complicated by bacteremic shock with a “failure” of blood pressure, tachycardia, a symptom complex of acute renal failure, pyonephrosis with purulent fusion of the renal parenchyma. Acute purulent pyelonephritis often develops against the background of gout, chronic alcoholism, diabetes mellitus, sickle cell anemia.
Approximately one in ten cases of acute pyelonephritis develops sepsis; with this combination, the prognosis depends on the specific pathogen and the patient’s immunocompetence, but the mortality rates are high and vary between 40-80%.
Chronic pyelonephritis, as a rule, is a consequence of untreated or undertreated acute, although this is not an absolute rule: there are cases of chronic pyelonephritis without an acute phase in history. Symptoms, in general, are similar to the clinical picture of acute pyelonephritis, but it is much less pronounced; often there are no subjective complaints at all, and pyelonephritis is detected during a routine laboratory examination for another reason or as part of a physical examination. However, the disease gradually progresses, and patients increasingly notice dull aching pains in the lower back, sometimes with irradiation to the coccyx and / or due to the meteorological factor (low air temperature, rainy weather); weakness, headaches, polakiuria (frequent urination), persistent decrease or lack of appetite. With an increase in functional failure of one or both kidneys (depending on the unilateral or bilateral localization of inflammation), symptoms of renal failure (swelling, hypertension, etc.) are added; in case of exacerbation, renal colic may develop, the lower parts of the urinary tract suffer. Exacerbation of chronic pyelonephritis is symptomatically similar to the onset of acute.
The first of these factors, i.e. ascending infections of the urogenital tract, is the cause of the predominance of females among patients in early childhood, adolescence, and adulthood. The anatomical structure of the female body (short straight urethra, proximity of the anus to the exit of the urethra, a very high probability of introducing foreign pathogenic and opportunistic flora with the onset of sexual activity and each change of partner) makes it much more vulnerable to bacterial invasions of this kind – which reflects the above statistics. In addition, purely female risk factors include pregnancy and childbirth (changes in the tone of the urinary tract, mechanical compression of the ureters by the uterus). There is evidence that over the past two to three decades, cases of pyelonephritis in pregnant women have become five times more frequent – which, however,
The second global factor contributing to the penetration of infection into the renal pelvis are any conditions, diseases and pathological processes that impede the passage of urine. This explains the leveling of gender differences in morbidity as we approach the elderly and senile age: a significant percentage of benign (prostate adenoma) and malignant tumors, chronic urethritis and prostatitis, age-related decrease in elasticity and contractile activity of muscle fibers that provide peristalsis and urodynamics – all this is largely degree increases the likelihood of developing pyelonephritis in men.
In addition, universal risk factors are: urolithiasis and other diseases associated with urinary tract obstruction; hypovitaminosis; diabetes; tuberculosis; any conditions and conditions leading to a weakening of the immune system (hypothermia, overwork, the presence of foci of chronic infection in other body systems, surgical interventions, etc.).
Returning to the question of the bacterial nature of pyelonephritis, it should be noted that in 15% of cases it is not possible to identify the pathogen.
Symptoms
Existing classifications of pyelonephritis distinguish many of its varieties, which differ in the type and phase of the course, severity, clinical manifestations, etc.
In general, acute pyelonephritis is characterized by a rapid increase in body temperature (up to 39-40) with a corresponding general condition – hyperhidrosis, weakness, headache, often with nausea, vomiting and loss of appetite. Many patients report muscle and joint pain, cloudy and foul-smelling urine, and occasionally urinary disorders. Pain syndrome, sensitivity to percussion are localized in the lumbar region.
In old age and during pregnancy, acute pyelonephritis can manifest itself relatively mildly, with a predominance of general intoxication symptoms.
Relatively rare dangerous forms include acute purulent pyelonephritis and necrotizing papillitis, which can be complicated by bacteremic shock with a “failure” of blood pressure, tachycardia, a symptom complex of acute renal failure, pyonephrosis with purulent fusion of the renal parenchyma. Acute purulent pyelonephritis often develops against the background of gout, chronic alcoholism, diabetes mellitus, sickle cell anemia.
Approximately one in ten cases of acute pyelonephritis develops sepsis; with this combination, the prognosis depends on the specific pathogen and the patient’s immunocompetence, but the mortality rates are high and vary between 40-80%.
Chronic pyelonephritis, as a rule, is a consequence of untreated or undertreated acute, although this is not an absolute rule: there are cases of chronic pyelonephritis without an acute phase in history. Symptoms, in general, are similar to the clinical picture of acute pyelonephritis, but it is much less pronounced; often there are no subjective complaints at all, and pyelonephritis is detected during a routine laboratory examination for another reason or as part of a physical examination. However, the disease gradually progresses, and patients increasingly notice dull aching pains in the lower back, sometimes with irradiation to the coccyx and / or due to the meteorological factor (low air temperature, rainy weather); weakness, headaches, polakiuria (frequent urination), persistent decrease or lack of appetite. With an increase in functional failure of one or both kidneys (depending on the unilateral or bilateral localization of inflammation), symptoms of renal failure (swelling, hypertension, etc.) are added; in case of exacerbation, renal colic may develop, the lower parts of the urinary tract suffer. Exacerbation of chronic pyelonephritis is symptomatically similar to the onset of acute.
Diagnostics
Comparison of the anamnesis, complaints of the patient, objective clinical manifestations, the results of a laboratory study of urine and blood provides the specialist with a fairly simple recognition of acute pyelonephritis. Diagnosis and reliable confirmation of the chronic form, as shown above, is much more problematic.
Bacteriological or serological studies are carried out to identify the pathogen. The state of the affected kidneys is assessed using standard methods for nephrology and urology: excretory urography, ultrasound, Zimnitsky and Nechiporenko tests, CT, etc.
Treatment
There is no single treatment regimen for pyelonephritis; in its manifestations, symptoms, consequences, this disease is too variable, and the therapeutic strategy is developed taking into account many individual factors.
In acute pyelonephritis, as in exacerbation of a chronic one, hospitalization of the patient is necessary, and urgent – in order to avoid very serious complications that require emergency surgical intervention.
In other cases, treatment is most often carried out on an outpatient basis. The main directions of therapy for pyelonephritis are adherence to bed rest, diet and a special regimen for fluid intake – all this is prescribed by the doctor on a strictly individual basis, i.e. amateur activity in this case is categorically contraindicated, not to mention self-treatment with whatever medicines or “folk remedies”. A course of antibiotics is prescribed, again exclusively individually, and prescriptions for acute and chronic pyelonephritis differ significantly. Measures are being taken for detoxification, immunocorrection and immunomodulation, normalization of urine outflow – in this regard, it is mandatory to cure the underlying disease or stop its exacerbation if pyelonephritis is secondary. Physiotherapy has a significant effect, incl.
It should be understood that the treatment of pyelonephritis, especially chronic, is a complex, lengthy, multi-stage process that takes many months, and often years. The position of the patient, the degree of his awareness and criticality regarding the disease, the quality and strength of the therapeutic alliance with the attending physician, the readiness to patiently and strictly follow the jointly agreed prescriptions – in this case play a critical role.
