肾皮质脓肿

　　1、发病原因

　　本病以上尿路结石引起梗阻，继发感染为最常见；其次是肾和输尿管畸形引起感染性肾积水；亦可继发于肾盂肾炎。致病菌以大肠埃希杆菌属为多见。肾皮脂组织遭到严重损坏，肾全部或一部分成为脓性囊。

　　2. Pathogenesis

　　When an infected and purulent kidney occurs due to urinary tract obstruction, renal pyelonephritis complicated with acute obstruction can manifest as sudden fever, chills, and lumbar pain. It usually rapidly develops into sepsis. When the infection of an atonic kidney develops into purulent pyelonephritis, if not diagnosed and treated in time, it will lead to complete destruction of the kidney.

　　Pain may occur when the patient bends over. Painful mass in the lumbar area and skin redness are late signs of renal cortical abscess. If renal pyelonephritis is not treated in time, it can penetrate the renal capsule to form a perinephric abscess. Perinephric abscess is mainly formed by the rupture of renal abscess into the perinephric space. It is caused by bacteria from other parts of the body spreading to the renal cortex through the blood circulation, forming small abscesses on the cortex surface. In about 25% of cases, the abscess can be cultured with various pathogenic bacteria. Bacteria can enter the blood circulation to cause sepsis.

　　Renal cortical abscess is more common in middle-aged and young adults aged 20 to 40, with a male-to-female ratio of 3:1. Typical clinical features include acute onset, chills, fever, lumbar pain, costovertebral angle tenderness. In the early stage of the disease, before the abscess breaks into the renal pelvis and calyces, urinary system symptoms do not occur. Physical examination may reveal lumbar swelling, painful mass in the lateral abdomen, and disappearance of physiological kyphosis of the spine.

　　When an infected and purulent kidney occurs due to urinary tract obstruction, renal pyelonephritis complicated with acute obstruction can manifest as sudden fever, chills, and lumbar pain. It usually rapidly develops into sepsis. Therefore, early detection, early diagnosis, and early and effective treatment are of great significance in preventing the progression of the disease.

　　1. Laboratory examination:Blood tests show moderate to severe leukocytosis and nuclear left shift. Before the abscess breaks into the renal pelvis and calyces, the urine is normal, and urine culture is sterile. Blood culture is often negative. According to the severity of renal lesions and renal function damage, serum creatinine and blood urea nitrogen may be normal or elevated. Patients with renal lesions concurrent with diabetes mellitus may have positive urine sugar and elevated blood sugar.

　　2. Imaging examination:The diagnosis and differential diagnosis of renal cortical abscess require imaging examinations. Excretory urography can usually only reveal some non-specific changes. When the renal cortical abscess increases in size, imaging of space-occupying lesions can be detected. Gallium (Ga67) citrate and indium In111 labeled leukocytes in radioactive isotope scanning are helpful for diagnosis. When the renal cortical abscess fuses and forms a thick-walled mass filled with pus, renal B-ultrasound examination can confirm the diagnosis, but in the early stage of abscess formation, renal ultrasound examination is prone to misdiagnose renal abscess as renal tumor. Similarly, renal arteriography cannot differentiate renal abscess from ischemic or cystic renal tumors. The most accurate imaging examination for diagnosing renal abscess is CT scan. Puncture and aspiration under ultrasound or CT guidance can not only make a definite diagnosis and determine the causative bacteria, but also establish a drainage channel for treatment.

　　Pay attention to eating light and easily digestible food, and avoid forbidden foods. Make the patient understand the importance and necessity of correct diet, and avoid eating hard, cold, and overeating rich in fat. To protect the kidneys, it is necessary to consume protein and carbohydrates, and it is not advisable to eat foods with too much fat. Excessive fat in the diet can easily lead to atherosclerosis of the renal arteries, causing atrophy and变性 of the kidneys, and leading to atherosclerotic kidney disease. Alkaline foods are beneficial to the kidneys and can prevent and treat urinary tract stones. It is also appropriate to eat some winter melon, white grass root, red bean, mung bean, etc., which are beneficial for diuresis, clearing heat, and protecting the kidneys.

　　The traditional treatment measures are the combination of antibiotics and surgical drainage. Recently, the use of antibiotics alone has successfully cured renal cortex abscess (especially caused by Staphylococcus aureus). The recommended antibiotics for Staphylococcus aureus infection are Novocillin II and Novocillin III, 100-200mg/kg, intravenous injection, once every 4 hours. Vancomycin, 1g intravenous injection, once every 12 hours. Cephalosporin V, 2g intravenous injection, once every 8 hours. The above antibiotics can be rotated, intravenous injection for 10-14 days, then switched to oral administration, for 14-28 days continuously. If there is no improvement in the condition after 48 hours of treatment, it should be considered as drug-resistant strain infection or accompanied by other diseases, such as perirenal abscess. At this time, under the guidance of ultrasound or CT, skin abscess puncture and drainage should be performed through the skin. If there is still no significant improvement in the condition after drainage, surgical operation is needed.