Apostematous pyelonephritis – suppuration of the renal parenchyma with the development of multiple small pustules (apostem) in it, is one of the late stages of acute pyelonephritis.
Etiology and pathogenesis
Regardless of the location of the primary purulent focus in the body, the infection penetrates the kidney hematogenically. Inflammatory infiltrates spread through the interstitial perivenous tissue, reaching the surface of the kidney into the subcapsular space. This leads to the appearance of pustules on the surface of the kidney. Unilateral apostematous pyelonephritis occurs as a result of obstruction of the upper urinary tract. The kidney affected by apostematous pyelonephritis is enlarged, congestive and full-blooded, a large number of small pustules are visible through the fibrous capsule; with the progression of apostematous pyelonephritis, the pustules merge, forming an abscess or carbuncle; when the process spreads to the parotid tissue, purulent paranephritis develops.
The clinic of the disease depends on the presence and degree of violation of the passage of urine. Characterized by general weakness, pain throughout the body, decreased appetite, nausea, sometimes vomiting, dry tongue, rapid pulse corresponding to body temperature, terrific chills followed by fever to 39-40 ° C and torrential sweats, pain in the kidney area; there are symptoms of irritation of the peritoneum, muscle tension of the anterior abdominal wall. Exudative pleurisy may develop if the infection spreads through the lymphatic pathways. The patient’s condition is severe, kidney function is impaired in the later stages, renal-hepatic syndrome with jaundice develops.
The diagnosis is justified by laboratory and radiological data: high blood leukocytosis with a shift of the leukocyte formula to the left, bacteriuria, leukocyturia. An overview urogram reveals a curvature of the spine towards the disease and the absence of a shadow of the lumbar muscle on this side. Kidney sizes are enlarged. When the upper segment of the kidney is affected, an effusion into the pleural cavity is determined. Excretory urography during the patient’s breathing or at the height of inhalation and exhalation determines the limitation of mobility of the affected kidney, its function is reduced. In the later stage of apostematous pyelonephritis and in violation of the passage of urine, these symptoms are more pronounced, the function of the affected kidney is sharply impaired, significant bacteriuria and leukocyturia are detected. Impaired function of the affected kidney can be established by excretory urography and chromocystoscopy. The renograms show a violation of vascularization, secretion and excretion. Differential diagnosis is carried out with infectious diseases, acute pancreatitis, acute cholecystitis, retrocecally located appendicular process.
Surgical treatment consists in decapsulation of the kidney, opening of ulcers, drainage of the paranephral space, and in case of impaired passage of urine – the renal pelvis by applying pyelo- or nephrostomy. In some cases, there is a need to remove the affected kidney. Broad-spectrum antibiotics, sulfonamides, nitrofurans are used. There is a change of antibiotics, infusion therapy, vitamin therapy, analgesics, antispasmodics. Cranberry juice, a decoction of plantain, horsetail, eleutherococcus extract are also useful.
The medical examination of patients who have undergone apostematous nephritis is reduced to monitoring the function of the remaining kidney if the patient has had a nephrectomy.
Treatment is carried out even after the patient is discharged for 4-6 months.
The prognosis is always serious due to the high mortality rate, reaching 5-10%, and the subsequent development of a chronic inflammatory process in the kidney.