Acute pyelonephritis is a nonspecific inflammatory lesion of the kidney parenchyma. The pathology is characterized by high fever with chills and sweating, headache, myalgia, arthralgia, general malaise, lower back pain, changes in urine by type of leukocyturia and pyuria. Diagnostics includes microscopic and bacteriological examination of urine, ultrasound of the kidneys; if necessary, excretory urography, radioisotope studies, tomography. A diet, copious drinking, antibiotics, nitrofurans, antispasmodics are prescribed. In obstructive pyelonephritis, the installation of a ureteral catheter-stent or puncture nephrostomy is indicated; in purulent-destructive processes, kidney decapsulation or nephrectomy is indicated.
ICD 10
N10 Acute tubulointerstitial nephritis
Meaning
Acute pyelonephritis is the most common kidney disease in modern urology. Pathology often occurs in childhood, when the load on the kidneys is very intense, and their morpho-functional development has not yet been completed. Girls suffer 10 times more often than boys. Women predominate among patients under the age of 40, and male patients prevail in the older age group. One or both kidneys may be affected.
Causes
Acute pyelonephritis develops with endogenous or exogenous penetration of pathogenic microorganisms into the kidney. Usually pathology is caused by E. coli (in 50% of cases), proteus, Pseudomonas aeruginosa, less often by Staphylococci or streptococci. In the primary process, the infection can enter the kidney hematogenically from the primary foci of inflammation in the genitourinary organs (with adnexitis, cystitis, prostatitis, etc.) or from distant organs. Less often, infection occurs by an ascending mechanism, along the wall or lumen of the ureter (with vesicoureteral reflux).
Secondary acute pyelonephritis is associated with impaired passage of urine against the background of ureteral strictures, ureteral obstruction by a stone, urethral strictures and valves, prostate adenoma, prostate cancer, phimosis, neurogenic bladder. The predisposing factors for the development of this form of the disease are hypothermia, dehydration, hypovitaminosis, fatigue, respiratory infections, pregnancy, diabetes mellitus.
Pathogenesis
Inflammation is associated not only with microbial invasion, but also with the ingress of the contents of the pelvis into the interstitial tissue, which is due to the reverse flow of urine, i.e., fornic reflux. The kidneys are full-blooded, somewhat enlarged. The mucous membrane of the renal pelvis is swollen, inflamed, ulcerated; inflammatory exudate may be present in the pelvis. In the future, numerous ulcers or abscesses may form in the cerebral and cortical layer of the kidney; sometimes purulent-destructive melting of the renal parenchyma is noted. The stages of acute pyelonephritis correspond to morphological changes occurring in the kidney.
The initial phase of serous inflammation is characterized by an increase and tension of the kidney, edema of the parotid fiber, perivascular infiltration of the interstitial tissue. With timely appropriate treatment, this stage undergoes reverse development; otherwise, it passes into the stage of purulent–destructive inflammation. In the stage of purulent inflammation, phases of apostematous pyelonephritis, carbuncle and kidney abscess are distinguished. Apostematous (pustular) pyelonephritis proceeds with the formation of multiple small pustules 1-2 mm in size in the cortical layer of the kidney.
In the case of fusion of pustules, a local suppurative focus may form – a kidney carbuncle that does not have a tendency to progressive abscess formation. Carbuncles have a size from 0.3 to 2 cm, can be single or multiple. With purulent melting of the parenchyma, a renal abscess is formed. The danger of a kidney abscess lies in the possibility of emptying the formed abscess into the paranephral tissue with the development of purulent paranephritis or retroperitoneal phlegmon.
With a favorable outcome, the infiltrative foci gradually dissolve, being replaced by connective tissue, which is accompanied by the formation of cicatricial retractions on the surface of the kidney. The scars initially have a dark red, then a white-gray color and a wedge-shaped shape, reaching to the pelvis at the incision.
Classification
Acute pyelonephritis can be primary (non-obstructive) and secondary (obstructive). The primary variant of the disease occurs against the background of normal outflow of urine from the kidneys; the secondary is associated with a violation of the patency of the upper urinary tract due to their external compression or obstruction. By the nature of inflammatory changes, the pathology may be serous or purulent-destructive (pyelonephritis apostematous, abscess or carbuncle of the kidney).
Symptoms
The course is characterized by local symptoms and signs of a pronounced general infectious process, which differ depending on the stage and form of the disease. Serous pyelonephritis proceeds more calmly; with purulent inflammation, pronounced clinical manifestations develop. In acute non–obstructive process, general symptoms of infection prevail; in obstructive – local symptoms.
The clinic of acute non-obstructive pyelonephritis develops at lightning speed (from several hours to one day). There is malaise, weakness, tremendous chills with a significant increase in temperature to 39-40 ° C, profuse sweating. Headache, tachycardia, arthralgia, myalgia, nausea, constipation or diarrhea, flatulence significantly worsens the state of health.
Of the local symptoms, there is pain in the lower back, spreading along the ureter to the hip area, sometimes to the abdomen and back. By nature, the pain can be constant dull or intense. Urination, as a rule, is not disturbed; the daily diuresis is reduced due to the abundant loss of fluid with sweat. Patients may pay attention to the turbidity of urine and its unusual smell.
Secondary pyelonephritis caused by urinary tract obstruction usually manifests with renal colic. At the height of the pain attack, fever with chills, headache, vomiting, thirst occurs. After profuse sweating, the temperature critically decreases to subnormal or normal figures, which is accompanied by some improvement in well-being. However, if the urinary tract obstruction factor is not eliminated in the coming hours, then the attack of colic and fever will recur again.
Purulent forms of pathology occur with persistent pain in the lower back, hectic fever, chills, sharp tension of the muscles of the abdominal wall and lumbar region. Against the background of severe intoxication, confusion and delirium may be noted.
Diagnostics
In the process of recognizing acute pyelonephritis, physical examination data are important. Palpation of the lumbar region and hypochondrium assesses the size of the kidney, consistency, surface structure, mobility, soreness. The kidney is usually enlarged, the muscles of the lower back and abdomen are tense, beating with the edge of the palm along the XII rib is painful, Pasternatsky’s symptom is positive. In men, it is necessary to conduct a rectal examination of the prostate and palpation of the scrotum, in women – a vaginal examination. Differential diagnosis is performed with appendicitis, cholecystitis, cholangitis, adnexitis.
- Laboratory diagnostics. In the urine, there is total bacteriuria, minor proteinuria, leukocyturia, with a secondary lesion – erythrocyturia. Bacterial urine culture allows you to determine the type of pathogen and its sensitivity to antimicrobial drugs. Blood counts are characterized by anemia, leukocytosis, increased ESR, toxic granularity of neutrophils.
- Ultrasound of the kidneys. It is used not only for diagnostics, but also for dynamic control of the treatment process. The value of the echoscopy data lies in the possibility of visualizing destructive foci in the parenchyma, the state of the paranephral fiber, and identifying the cause of obstruction of the upper urinary tract.
- X-ray techniques. When reviewing urography, attention is drawn to the increase in the size of the kidneys, the swelling of the contour with an abscess or carbuncle, the indistinctness of the outlines of the paranephral fiber. With the help of intravenous urography, the restriction of the mobility of the kidney during breathing is determined, which is a characteristic sign of an acute inflammatory process. Accurate detection of destructive foci, causes and level of obstruction in acute purulent pyelonephritis is possible with the help of kidney CT.
Treatment
The patient is hospitalized; treatment is carried out under the supervision of a urologist. Therapeutic tactics for non-obstructive and obstructive acute pyelonephritis, serous and purulent-destructive forms differ. General measures include the appointment of bed rest, copious drinking (up to 2-2.5 liters per day), a fruit and dairy diet, easily digestible protein nutrition.
In the primary case of inflammation, pathogenetic therapy immediately begins, which is based on antibiotics active against gram-negative flora – cephalosporins, aminoglycosides, fluoroquinolones. When choosing an antimicrobial drug, the results of an antibioticogram are also taken into account. Additionally, NSAIDs, nitrofurans, immunocorrectors, detoxification therapy are prescribed.
When an obstruction is detected, decompression is the primary measure – the restoration of urodynamics in the affected kidney. For this purpose, catheterization of the pelvis with a ureteral catheter or a stent catheter is undertaken, in some cases, percutaneous nephrostomy is punctured.
In the presence of purulent-destructive foci, kidney decapsulation and nephrostomy are resorted to, with the help of which a decrease in intrarenal pressure is achieved. Upon detection of formed ulcers, their autopsy is performed. In the case of total damage to the renal parenchyma and the impossibility of organ-preserving tactics, nephrectomy is performed.
Prognosis and prevention
Timely adequate therapy makes it possible to achieve the cure of acute pyelonephritis in most patients within 2-3 weeks. In a third of cases, there is a transition to a chronic form (chronic pyelonephritis) with subsequent sclerosis of the kidney and the development of nephrogenic arterial hypertension. Complications may include paranephritis, retroperitonitis, urosepsis, renal failure, bacteriotoxic shock, interstitial pneumonia, meningitis. Severe septic complications worsen the prognosis and often cause death.
Prevention is the rehabilitation of foci of chronic inflammation, which can serve as sources of potential hematogenic introduction of pathogens into the kidneys; elimination of the causes of possible obstruction of the urinary tract; hygiene of the genitourinary organs to prevent the upward spread of infection; compliance with aseptic and antiseptic conditions during urological manipulations.