Differential diagnosis of acute pyelonephritis. Clinical picture, additional diagnostic methods, differential diagnosis. chronic pyelonephritis

Due to the nonspecific clinical picture of pyelonephritis in children and the lack of laboratory research, during differential diagnosis, the paramedic should Special attention devote clinical methods diagnostics paramedic pediatric pyelonephritis

Abdominal pain in combination with fever often requires the exclusion of acute surgical pathology(more often - acute appendicitis). In fact, for any fever without signs of damage respiratory tract and in the absence of other obvious local symptoms it is necessary to exclude pyelonephritis in children.

If changes are detected in urine tests, differential diagnosis is carried out with the diseases listed below.

Acute glomerulonephritis (AGN) with nephritic syndrome

Leukocyturia - common symptom of this disease, but in typical cases it is minor and short-lived. Sometimes, especially at the onset of AGN, the number of neutrophils in the urine exceeds the number of erythrocytes (more than 20 cells in the field of view). Bacteria in the urine are not detected (abacterial leukocyturia). A more rapid disappearance of leukocytes from urine is characteristic than normalization of protein concentration and cessation of hematuria. Fever and dysuria in acute glomerulonephritis are less common than in pyelonephritis. For both diseases, complaints of pain in the abdomen and lower back are typical, however, unlike pyelonephritis, acute glomerulonephritis is characterized by swelling and arterial hypertension.

Abacterial interstitial nephritis (IN)

Immune damage to the basement membrane of the tubules is considered decisive in its development. It happens by various reasons- toxic effects (medicines, heavy metals, radiation damage), metabolic changes (impaired metabolism of uric or oxalic acid), etc. Damage to the interstitium of the kidneys develops as if infectious diseases (viral hepatitis, Infectious mononucleosis, diphtheria, hemorrhagic fever), and when rheumatoid arthritis and gout, arterial hypertension, after kidney transplantation. At interstitial nephritis the clinical picture is also scanty and nonspecific, changes are characteristic laboratory tests: leukocyturia and signs of tubular dysfunction. However, unlike pyelonephritis, there are no bacteria in the urine sediment and lymphocytes and/or eosinophils predominate.

Kidney tuberculosis

For small but persistent leukocyturia that does not decrease when using standard antibacterial drugs(especially with repeated negative result bacteriological examination of urine), should be excluded specified disease. Kidney damage is the most common extrapulmonary form of tuberculosis.

The paramedic needs to know that, like pyelonephritis, it is characterized by complaints of lower back pain and dysuria, signs of intoxication, slight proteinuria, changes in urine sediment (the appearance of leukocytes and a small number of red blood cells). Differential diagnosis is complicated by the fact that in the early (parenchymal) phase of the disease there are no specific radiological changes.

To make a diagnosis, a special urine test is required to determine Mycobacterium tuberculosis (they are not detected by standard methods).

Lower urinary tract infection (cystitis)

According to the picture of urine analysis and according to bacteriological examination, the diseases are almost identical. Although the approaches to their treatment are largely similar, differential diagnosis necessary, firstly, to determine the duration and intensity antibacterial therapy and, secondly, to clarify the prognosis (with cystitis there is no danger of damage to the kidney tissue).

Acute diseases can be distinguished by the clinical picture: with cystitis, the leading complaint is dysuria in the absence or low severity of general infectious symptoms (epithelium Bladder has practically no resorptive ability), therefore, a fever above 38 ° C and an increase in ESR of more than 20 mm/h make one think more about pyelonephritis than cystitis. Additional arguments in favor acute pyelonephritis- complaints of pain in the abdomen and lower back, transient disturbances concentrating ability of the kidneys.

At chronic course infections urinary tract the clinical picture of both diseases is asymptomatic, which makes recognition difficult for the paramedic and gives rise to the problem of overdiagnosis (any recurrent infection is clearly regarded as chronic pyelonephritis).

Signs of impaired renal tubular function play a major role in determining the level of damage. To identify them, in addition to the standard Zimnitsky test, it is recommended to carry out stress tests for concentration and dilution, determination of urine osmolarity, excretion of ammonia, titratable acids and electrolytes in urine. A highly informative, but expensive method is to determine the content of beta2-microglobulin in urine (this protein is normally 99% reabsorbed by the proximal tubules, and its increased secretion indicates their damage). It is also recommended to conduct radionuclide studies to identify focal changes in the kidney parenchyma. It should be noted that even with sufficient full examination in almost 25% of cases it is difficult to accurately determine the level of damage.

Inflammatory diseases of the external genitalia

Girls even have significant leukocyturia (more than 20 cells in the field of view), but without fever, dysuria, abdominal pain and without laboratory signs inflammation always makes one think that the cause of changes in urine sediment is inflammation of the external genitalia. When confirming the diagnosis of vulvitis in similar cases it is advisable to appoint local treatment and repeat the urine test after the symptoms of the disease disappear, rather than rushing to use antibacterial drugs. However, with the above complaints, even in cases of obvious vulvitis, the paramedic should not discount the possibility of developing an ascending infection. A similar tactic is justified for inflammatory processes of the genitals in boys.

Long-term consequences of pyelonephritis in children

The recurrence rate of pyelonephritis in girls in the next year after the onset of the disease is 30%, and at 5 years - up to 50%. For boys, this probability is lower - about 15%. The threat of recurrence of the disease increases significantly with narrowing of the urinary tract or with urodynamic disturbances. Nephrosclerosis occurs in 10-20% of patients with pyelonephritis (the risk of its development directly depends on the frequency of recurrence).

Obstructive uropathy or reflux themselves can lead to the death of the parenchyma of the affected kidney, and when pyelonephritis is added, the risk increases. According to numerous studies, it is pyelonephritis in children against the background of gross congenital anomalies of the urinary tract that is the main cause of the development of terminal chronic renal failure. In cases of unilateral damage, shrinkage of the kidney can lead to the development of arterial hypertension, but general level glomerular filtration does not suffer, since compensatory hypertrophy of the undamaged organ develops (with bilateral damage, the risk of developing chronic renal failure is higher).

The paramedic should remember that the long-term consequences of pyelonephritis are arterial hypertension and chronic renal failure- do not necessarily arise in childhood, but can develop in adulthood (and in young and able-bodied people).

Pyelonephritis in children - special case urinary tract infections (UTIs). common feature All UTIs are the growth and reproduction of bacteria in the urinary tract.

Urinary tract infections are the second most common after infectious pathology respiratory tract. About 20% of women experience them at least once in their lives. The disease recurs quite often (in more than 50% of cases in girls and approximately 30% in boys). There are UTIs with lesions:

• lower urinary tract - cystitis, urethritis;
• upper - pyelonephritis.

Pyelonephritis is a nonspecific acute or chronic microbial inflammation of the epithelium collecting system and renal interstitium with secondary involvement of tubules, blood and lymphatic vessels.

Pyelonephritis in children is the most serious type of UTI according to prognosis; it requires timely diagnosis And adequate treatment, since when the interstitium of the kidneys is involved in the inflammatory process, there is a risk of their sclerosis and the development of serious complications (renal failure, arterial hypertension).

It is difficult to determine the true proportion of pyelonephritis in children in the structure of all UTIs, since in almost a quarter of patients it is not possible to accurately determine the location inflammatory process. Pyelonephritis, like UTIs in general, occurs in any age groups: in the first 3 months of life, it affects boys more often, and at an older age it is approximately 6 times more common in females. This is due to the structural features of the female genitourinary system, allowing easy colonization urethra microorganisms and upward spread of infection: the proximity of the external opening of the urethra to anus and the vagina, its short length and relatively large diameter, the peculiar rotational movement of urine in it.

The incidence of pyelonephritis is characterized by three age peaks:

• early childhood (up to about 3 years) - the prevalence of UTI reaches 12%;
• young age (18-30 years) - women are mostly affected, the disease often occurs during pregnancy;
• elderly and senile age (over 70 years) - the incidence in men is increasing, which is associated with the greater prevalence of prostate pathology, as well as with an increase in the frequency chronic diseases- risk factors ( diabetes, gout).

Pyelonephritis that occurred in early childhood, often turns into chronic form, worsening during puberty, at the beginning of sexual activity, during pregnancy or after childbirth.

Chronic pyelonephritis most often has to be differentiated from kidney tuberculosis, glomerulonephritis, arterial hypertension, and renal hypoplasia.

In cases where chronic pyelonephritis manifests itself as isolated arterial hypertension syndrome, it is necessary to carry out differential diagnosis with hypertension and symptomatic arterial hypertension, chronic glomerulonephritis, polycystic kidney disease.

In the complaints of patients with chronic pyelonephritis, dysuria, pain in lumbar region often unilateral in nature, a tendency to unmotivated low-grade fever, which is not typical for chronic glomerulonephritis and hypertension.

In chronic pyelonephritis, attention is drawn to the young age of patients, anamnestic indications of previous cystitis, pyelitis, and the presence of urolithiasis.

Signs of nephrotic syndrome should always be assessed as a strong argument in favor of chronic glomerulonephritis. Short-term swelling in the past or during the study of the patient also indicates chronic glomerulonephritis.

Malignant hypertonic disease differs from pyelonephritis and glomerulonephritis in the absence of bacteriuria, the absence or low content of protein in the urine, as well as in the course of chronic renal failure developing in terminal stages kidney diseases.

For several years, isolated arterial hypertension may remain not only the first, but also the only sign of latent pyelonephritis. Therefore, a negative history and absence of changes in urine are not sufficient to exclude pyelonephritis from possible reasons arterial hypertension. X-ray examination methods are of decisive importance for the diagnosis of pyelonephritis, including, if necessary, contrast vasography of the kidneys, as well as radioisotope research. Most often, asymmetry in the size and function of the kidneys, deformations of the renal collecting system on excretory urograms, and the “burnt wood” symptom on angiograms are revealed. Morphological research methods remain highly informative in differential diagnosis.

Chronic glomerulonephritis differs from pyelonephritis by the predominance of erythrocytes over leukocytes in the urine, the glomerular type of proteinuria (penetration of proteins with high molecular weight into the urine), and cylindruria. According to ultrasound, bilateral, symmetrical kidney damage; kidney sizes are normal or enlarged in nephrotic and nephritic syndrome, reduced in nephrosclerosis; there is no damage to the pyelocaliceal system. The most reliable method of differential diagnosis in these cases is a kidney biopsy.

In favor kidney tuberculosis evidence of previous tuberculosis of other organs, dysuria, hematuria, cicatricial constrictions upper urinary tract, proteinuria, less pronounced predominance of leukocyturia over erythrocyturia. Reliable signs nephrotuberculosis are: the presence of Mycobacterium tuberculosis in the urine, persistently acidic reaction of urine, a typical picture of tuberculous lesions of the bladder during cystoscopy and characteristic radiological signs diseases.

Unilateral chronic pyelonephritis in the sclerosis phase must be differentiated from kidney hypoplasia . Crucial importance in these cases belongs to x-ray research methods. Uneven contours, a denser shadow of the kidney, deformation of the calyces, papillae, pelvis, changes in RCT, a significant decrease in kidney function, the presence of the “burnt wood” symptom indicate pyelonephritic shrinkage of the kidney, while signs of renal hypoplasia are a miniature pelvis and calyces without signs of them deformations, smooth contours and normal tissue density of the organ, unchanged ratio of the area of ​​the pyelocaliceal system to the area of ​​the kidney, its relatively satisfactory function and the absence of a history of data on pyelonephritis.

12. Complications chronic pyelonephritis:

chronic renal failure

nephrogenic arterial hypertension

· nephrolithiasis

· pyonephrosis

Necrosis of the renal papillae.

· paranephritis

· bacteremic shock

13. Principles of treatment of chronic pyelonephritis.

1. Increase fluid intake for the purpose of detoxification and mechanical sanitation of the urinary tract. Water load is contraindicated if there is:

• urinary tract obstruction, postrenal acute renal failure;
• nephrotic syndrome;
• uncontrolled arterial hypertension;
• chronic heart failure, starting from the second stage IIA;
• gestosis in the second half of pregnancy.

2. Antimicrobial therapy - This is the basic treatment for pyelonephritis. The outcome of chronic pyelonephritis depends precisely on the competent prescription of antibiotics.

3. Treatment of pyelonephritis is supplemented, according to indications, with antispasmodics, anticoagulants (heparin) and antiplatelet agents (pentoxifylline, ticlopidine).

Differential diagnosis of acute pyelonephritis is based on the history of clinical symptoms and special methods research. Among the latest special place takes a urine test.

When studying the anamnesis, special attention should be paid to identifying recent purulent process, as well as previous attacks of pyelonephritis (exacerbation of chronic pyelonephritis), which has important for prognosis and treatment. It should be taken into account that acute pyelonephritis can complicate the course of not only acute purulent processes, but also chronic ones (sluggish sepsis, subacute septic endocarditis, etc.).

When examining urine, it is necessary to pay attention to three circumstances:

1. with hematogenous pyelonephritis, changes in urine sediment may be absent during the first few days of the disease;
2. in patients with any acute purulent disease, pathological elements (protein, casts, red blood cells, etc.) are sometimes detected in the urine as a result of exposure to microbial toxins and products of increased catabolism;
3. the presence of pus in the urine may be caused by another localization of the inflammatory process (prostate, lower urinary tract).

Acute pyelonephritis is characterized by oliguria, high specific weight, proteinuria, pyuria, hematuria and bacteriuria, and sometimes uria. Oliguria and high specific gravity of urine depend on significant fluid losses through the lungs and skin, as well as from increased catabolism.

Proteinuria usually ranges from 1-3% 0 . Sometimes - a moderate number of hyaline casts, less often epithelial ones. With a longer or more severe process, granular and even waxy casts are found. Leukocyte casts are pathognomonic for pyelone frit. The presence of cylinders makes it possible to clarify the renal origin of pyuria.

The hematuria of most patients is microscopic, but may be macroscopic. Emergence renal colic and macrohematurism during acute pyelonephritis can be observed with necrosis of the renal papillae.

The most important symptom of pyelonephritis is intense pyuria. It is absent in the first days of hematogenous introduction of infection into the kidneys and: a distant focus, as well as in case of ureteral obstruction.

Bacteriuria often precedes the onset of pyelonephritis and is its constant symptom. It is found in many patients even after disappearance clinical manifestations diseases. Bacteriuria is determined in most cases by the bacterioscopic method.

However, to clarify the type of microflora and its sensitivity to antibiotics, bacteriological examination and differential diagnosis of acute pyelonephritis are necessary.

When counting bacteria, more than 100,000 bacteria are found in 1 ml of urine in 95% of patients. Urine is a good medium for the proliferation of microbes, and a large number of them are found even with a small amount coming from an inflammatory focus in the kidney. A small number of bacteria can be observed when the patency of the ureter is impaired.

Chromocystoscopy makes it possible to determine the condition of the bladder and kidney function. In acute pyelonephritis, cloudy urine may be visible from the ureteral orifice of the affected kidney (or both kidneys), as well as slow or weakened secretion of indigo carmine.

By using plain radiograph it is possible to establish the presence of a calculus, an increase in the size of the kidney, blurred or absent contours of the lateral edge psoas muscle during the transition of the inflammatory process to paranephrism.

Differential diagnosis is carried out between acute pyelonephritis and general infectious diseases, as well as between acute pyelonephritis and other inflammatory and purulent processes of the kidneys, urinary tract and genital organs.

It is necessary to differentiate acute pyelonephritis from general infectious diseases, in particular typhoid fever, malaria, sepsis, mainly in the absence of local manifestations of the disease.

Before the elimination of malaria in our country, an erroneous diagnosis of acute pyelonephritis was often made. In areas where malaria is endemic, chills accompanied by a rise in temperature and subsequent heavy sweating naturally suggested malaria. The absence of plasmodium in the blood and pyuria allow us to establish the correct diagnosis.

Differential diagnosis with typhoid fever carried out on the basis of changes in the tongue, bradycardia, rash, enlarged spleen, leukopenia, etc., characteristic of typhus.

Acute pyelonephritis can be one of the manifestations of sepsis or a single consequence of infection entering the kidney from a distant purulent focus. In the first case, there are other localizations of the disease process, in the second, the picture develops like acute pyelonephritis. Identifying and eliminating the source of infection is of great importance.

Difficulty in differential diagnosis between pyonephrosis and acute pyelonephritis occurs during periods of ureteral obstruction with impaired outflow of pus from the pyelonephrotic sac. From questioning patients, it is possible to clarify the duration of kidney disease during pyonephrosis; patients often report that their urine was always cloudy, but became clear when their condition worsened, chills and fever appeared.

In such cases, when examining urine, a decrease in the number of leukocytes is noted, despite the deterioration general condition. The kidney may be enlarged. A comparative leukocytosis test (determining the number of leukocytes in blood taken from the skin of a finger, the skin of the lumbar region in the area of ​​the right and left kidneys) can provide a very significant help in diagnosing pyelonephritis.

In every patient with acute pyelonephritis or suspected acute pyelonephritis, the lower urinary tract and prostate gland must be carefully examined. The cause of chills, fever, and pyuria may be an acute purulent disease of these organs. We should not forget that acute prostatitis can be complicated by acute pyelonephritis.

Symptoms and clinical course. The clinical course of chronic pyelonephritis is characterized by a persistent course and a tendency to exacerbations. During the remission phase, there are no symptoms of the disease. With active inflammation, there is a picture of acute pyelonephritis with all its inherent symptoms. Exacerbation of chronic pyelonephritis can be facilitated by cooling and changes in climatic living conditions, increased physical and even mental stress, and disturbances in urodynamics.

As the disease progresses and morphological changes in the kidney worsen, the appearance of clinical symptoms and beyond the exacerbation of the disease. They can be divided into general and local. Local symptoms include a feeling of heaviness or dull ache in the lumbar region and cloudy urine. Among the general symptoms, weakness and fatigue, headache, dry mouth, decreased performance, occasional low-grade fever, pallor of the skin, and a decrease in the relative density of urine stand out, which is increasingly noticeable to the patient.

Over time, the functioning kidney parenchyma is replaced by connective tissue, and this becomes a condition for kidney shrinkage. In the case of bilateral localization of the pathological process, the total function of the kidneys is disrupted and, in the end, patients die from uremia.

According to the activity of the inflammatory process in the kidney, chronic pyelonephritis is divided into three phases: the active inflammatory process phase, the latent inflammatory process phase and the remission phase. Each of these phases is characterized by the severity of clinical symptoms of the disease and laboratory parameters. At latent phase inflammation, clinical symptoms of the disease are absent, and only the presence of a large number of leukocytes in the urine with the detection of active leukocytes among them indicates the presence of pyelonephritis. During the active phase of chronic pyelonephritis, low-grade fever is observed, and sometimes more heat body, malaise, increased fatigue, pain in the lumbar region, chills, leukocyturia over 25,000 in 1 ml of urine, bacteriuria over 100,000 or more in 1 ml of urine, the presence of active leukocytes and Sternheimer-Malbin cells, an increase in the number of medium molecules in the blood two to three times, an increase in ESR. The remission phase is sometimes called the clinical recovery phase, in which there are no complaints and laboratory values ​​are within normal limits. Characteristics of the clinical course of chronic pyelonephritis according to the Research Institute of Urology of the Russian Ministry of Health are given in Table. 7.2.

Table 7.2. Characteristics of the clinical course of chronic pyelonephritis

Diagnostics. In almost half of patients, chronic pyelonephritis occurs without pronounced urological symptoms. In such cases, for the correct diagnosis of the disease, a carefully collected anamnesis is of particular importance, allowing one to establish the presence of primary diseases or anomalies of the genitourinary organs, purulent foci in the body or recently suffered acute infectious diseases.

Among all laboratory tests aimed at identifying chronic pyelonephritis, priority is given to urine tests. If conventional microscopy of its sediment does not reveal an increased number of leukocytes, then studies are necessary to detect hidden leukocyturia: the Kakovsky-Addis test (the number of leukocytes in daily urine), the Amburger test (the number of leukocytes released in 1 minute), the Almeida-Nechiporenko test (the number leukocytes in 1 ml of freshly released urine). No less important for identifying chronic pyelonephritis is determining the degree of bacteriuria. The presence of at least 10 5 colony-forming units (CFU) of microorganisms in 1 ml of urine confirms pyelonephritis.

At asymptomatic For chronic pyelonephritis, provocative tests (prednisolone or pyrogenal) can be used to identify it for special indications. The rationale for the presence of chronic pyelonephritis will be more convincing if leukocyturia is detected after provocation. A decrease in the relative density of urine, a decrease in the rate of tubular secretion and reabsorption have some diagnostic value, since in chronic pyelonephritis the function of the tubules is primarily impaired.

Radiological symptoms characteristic of the initial stage of development of chronic pyelonephritis have not yet been described. In case of long-term chronic pyelonephritis, an overview urogram shows a decrease in size and an increase in the density of the kidney shadow, caused by cicatricial changes in its parenchyma.

As with a number of other diseases, with pyelonephritis two processes simultaneously occur in the kidney: destruction and scarring. Depending on the predominance of one of the processes in the excretory urograms, the cups can be moved apart and their necks narrowed (the predominance of infiltration processes), or vice versa - the cups acquire a club-shaped shape and come closer together (the predominance of scarring processes). On delayed urograms, one can see a delay in the removal of the radiopaque substance from the diseased kidney.

If you connect the cups of the diseased kidney on the excretory urogram of a patient with chronic pyelonephritis, you may get a broken line, whereas normally it should be convex, parallel to the outer contour of the kidney. This is Hodson's symptom, which is found in approximately every third patient with chronic pyelonephritis.

The decrease in the amount of functioning parenchyma in patients with chronic pyelonephritis can be assessed by the percentage ratio of the area of ​​the collecting system to the area of ​​the entire kidney. If this figure is above 40%, then there is reason to talk about chronic pyelonephritis.

Characteristic arteriographic signs of chronic pyelonephritis are a decrease in the number and even complete disappearance of small segmental arteries, a decrease in length and a conical narrowing to the periphery of large segmental arteries, which “lose” their branches (“burnt tree”). As the process of kidney shrinkage worsens, its shadow on the nephrogram becomes smaller, and the number of kidney vessels also decreases (Fig. 7.4).

Radionuclide diagnostics does not give an exact answer to the question of the presence or absence of chronic pyelonephritis. At the same time, radiorenography makes it possible to evaluate the secretory function of the tubules and the function of urine excretion by each kidney separately and characterize these processes in the dynamics of monitoring the patient. Scintigraphy sometimes reveals a defect in the accumulation of radiopharmaceuticals according to the localization of scar-sclerotic changes in the kidney. In the latter case, differential diagnosis with a kidney tumor is necessary.

Rice. 7.4. Aortogram. Chronic pyelonephritis. Shrinkage of the right kidney

Differential diagnosis. Differential diagnosis of chronic pyelonephritis, in addition to kidney neoplasms, must be carried out with hypoplasia, tuberculosis, glomerulonephritis, and amyloidosis of the kidney.

When the kidney shrinks, differential diagnosis with renal hypoplasia is necessary, for which an X-ray examination is performed. On radiographs with kidney hypoplasia, a miniature pelvis and cups are identified, but without signs of their deformation, the contours of a small kidney are smooth, while when the kidney shrinks, its uneven contours, deformation of the pelvis and cups, a change in the renalcortical index, a significant decrease in kidney function are revealed, and on angiograms - a decrease in the number of blood vessels and the “burnt wood” symptom.

Chronic glomerulonephritis differs from chronic pyelonephritis by the predominance of erythrocytes over leukocytes in the urine, the presence of cylindruria and the glomerular type of proteinuria. In case of kidney tuberculosis, Mycobacterium tuberculosis is detected in the urine, and signs characteristic of kidney tuberculosis are found on x-rays.

Treatment should provide:

Elimination of causes causing disturbances in the outflow of urine or renal circulation;

Carrying out etiotropic antibacterial therapy;

Prescription of immunocorrective agents.

To restore the outflow of urine, surgical interventions are performed depending on the “primary” disease - nephrolithiasis, BPH, nephroptosis, hydronephrosis, etc.

Antibiotics and chemotherapeutic agents are prescribed taking into account the sensitivity of the urine microflora to antibacterial drugs. Semi-synthetic penicillins, cephalosporins, aminoglycosides, tetracyclines, macrolides, fluoroquinolones, and chemotherapy are used for treatment. Doses of drugs and duration of treatment for patients with chronic pyelonephritis depend on the phase of activity of the inflammatory process and functional state kidneys One of the principles of treating patients with chronic pyelonephritis is the frequent change of antibacterial agents due to the rapid development of resistance of pathogens to them.

Forecast in chronic pyelonephritis depends on the duration of the disease and becomes unfavorable with the development of chronic renal failure and nephrogenic arterial hypertension.