What Is Chronic Pyelonephritis?

Pyelonephritis (pyelonephritis) refers to inflammation that occurs in the kidney and pyelone, mostly caused by bacterial infections, and is divided into acute and chronic pyelonephritis according to the course of the disease. It is generally believed that chronic pyelonephritis refers to pyelonephritis with a duration of more than six months or one year. But this definition is currently controversial. The pathological manifestations of chronic pyelonephritis are: chronic inflammation of the renal pelvis and calyces, enlarged and deformed renal pelvis, scar formation in the renal cortex and papilla, deformation of the renal medulla, thickening of the renal pelvis, calyx mucosa, and ureteral duct wall, serious Renal parenchyma was extensive. Chronic pyelonephritis is an important cause of chronic renal insufficiency.

Basic Information

English name: Chronic Pyelonephritis
Visiting department: Nephrology
Common locations: kidney

Common causes: Bacterial infections
Common symptoms: Fatigue, low fever, anorexia, backache, low back pain, frequent urination, urgency, dysuria; polyuria, thirst, dehydration; end-stage renal insufficiency, edema, anemia, fatigue, etc.

Causes of chronic pyelonephritis

Some people have proposed that acute and chronic pyelonephritis are classified according to the duration of the disease (more than half a year or one year), but follow-up studies at home and abroad have found that most patients have multiple recurrent urinary tract infections without complicated urinary tract conditions. After years of follow-up, he did not develop chronic pyelonephritis. Therefore, chronic pyelonephritis is closely related to complicated urinary tract conditions. Chronic pyelonephritis is rarely seen without urinary tract complications. Common urinary tract complications include reflux nephropathy and obstructive nephropathy. Reflux nephropathy refers to kidney disease caused by bladder ureteral reflux and intrarenal reflux; obstructive nephropathy refers to kidney disease caused by urinary flow disorders caused by various reasons (such as urinary tract stones, tumors, enlarged prostate, etc.). Both of these may be co-infected. Long-term prolongation can cause renal fibrosis and deformation, and chronic pyelonephritis will occur, eventually affecting renal function.

Clinical manifestations of chronic pyelonephritis

The manifestations of chronic pyelonephritis are very different from acute pyelonephritis, and its onset and duration are very hidden. Divided into three parts:

Manifestations of urinary tract infection

Not obvious, may have fatigue, hypothermia, anorexia, etc., intermittent pyelonephritis symptoms such as backache and low back pain, may be accompanied by symptoms of lower urinary tract infection such as frequent urination, urgency, dysuria. Can be expressed as intermittent asymptomatic bacteriuria.

2. Performance of chronic interstitial nephritis

If urine concentration decreases, polyuria and nocturia may occur, and prone to thirst and dehydration; decreased renal tubular reabsorption capacity may be manifested as hyponatremia, hypokalemia, and hyperkalemia may occur during renal insufficiency ; Renal tubular acidosis is common. Chronic pyelonephritis is mainly manifested by impaired renal tubular function, which is often more prominent than impaired glomerular function.

3. Chronic Renal Insufficiency <br /> Renal insufficiency may develop to the end stage, and may have edema, fatigue, loss of appetite, and anemia.

Chronic pyelonephritis

Routine urine test

The easiest and most reliable method. Where more than 5 (> 5 / HP) white blood cells become pyuria in each high-power field, sometimes white blood cell casts, bacteriuria, and microscopic hematuria can be found. Occasionally a small amount of proteinuria, if more proteinuria indicates that glomeruli may be involved.

2. Urine bacteriological examination

More than 95% of urinary tract infections are caused by Gram-negative bacteria, and other parasitic bacteria such as Staphylococcus epidermidis, lactic acid bacteria, anaerobic bacteria, coryneform bacteria, etc. rarely cause urine sensation. It is clinically significant to have a cleaned mid-urinary colony count greater than 105 / ml. The American Academy of Infectious Diseases recommends criteria: symptoms of pyelonephritis and a colony count of 104 / ml or more can be considered infection. Urine bacterial culture can help identify pathogenic strains and perform drug sensitivity tests to improve antibiotic treatment.

3.X-ray inspection

Intravenous or retrograde pyelography has characteristic signs, that is, deformation, dilation or narrowing of the renal pelvis and calves, and contraction of the renal papilla.

4. Ultrasound

The most widely used and easiest imaging method. The shape of the kidney is uneven, the size of the two kidneys is different, the structure of the collective system is disordered, and the renal pelvis is separated or dilated. Later, cortical echo enhancement and thinning can be seen.

5. Urine concentration function test

Low specific gravity urine, urine glucose positive, decreased urine freezing point osmotic pressure and other manifestations may appear, but lack specificity.

6. Renal function test

In the later stages, renal dysfunction may occur, such as an increase in creatinine, urea nitrogen, and cystatin C, also known as cystatin C; the glomerular filtration rate decreases.

Diagnosis of chronic pyelonephritis

A clinical diagnosis can often be made based on a history of chronic urinary tract infection combined with specific manifestations of renal imaging. The current pathological diagnostic criteria are: in addition to changes in chronic interstitial nephritis, there are also renal calves, pyelitis, fibrosis and deformation, and a history of urinary tract infections in history or bacteriological history.

Differential diagnosis of chronic pyelonephritis

Renal tuberculosis

Renal tuberculosis may also have low fever, fatigue, low back pain, frequent urination, urgency, and dysuria. A few years later, casein-like changes can cause renal parenchymal damage, deformation of the renal pelvis and calves, and impaired renal function. However, the detection of pulmonary tuberculosis, prostate, epididymis, and pelvic tuberculosis by X-ray examination of the lung helps to distinguish this disease. Positive urine tuberculosis culture and detection of urinary tuberculosis by polymerase chain reaction are helpful for differential diagnosis.

2. Chronic glomerulonephritis

If it shows edema and a lot of proteinuria, it is not difficult to identify it. The amount of urinary protein in pyelonephritis is generally less than 1-2 g / day, and glomerular disease should be considered if it is greater than 3 g / day. Occult nephritis usually has more red blood cells in urine, while pyelonephritis is mainly white blood cells. In addition, symptoms such as urine culture, chronic low fever, and frequent urination can also help in the differential diagnosis. The diagnosis of advanced chronic glomerulonephritis complicated with urinary tract infection is difficult. At this time, detailed medical history and clinical characteristics can be analyzed to identify the disease.

3. Prostatitis

Mostly occur in men over 50 years of age, prostatic hypertrophy, urinary tube placement, cystoscopy and other conditions are prone to occur. May have lumbosacral and perineal pain as well as frequent urination, dysuria, white blood cells are routinely found in urine. However, in addition to abnormal urine tests, other clinical manifestations of prostatitis are often not obvious. Checking the number of white blood cells in the prostate fluid> 10 / HP and prostate B ultrasound is helpful for differential diagnosis.

Chronic Pyelonephritis Treatment

General treatment

Encourage more water and frequent urination. Have fever and other symptoms of systemic infection should stay in bed. Active treatment of predisposing factors, such as kidney stones, ureteral deformities, reflux nephropathy, etc.

2. Anti-infective treatment

The pathogenic bacteria of chronic pyelonephritis are often complicated, it is best to determine the bacterial type by urinary bacterial culture, and antibiotic treatment under the guidance of drug sensitivity test.

3. Efficacy judgment

(1) The clinical cure symptoms disappeared. After 72 hours of discontinuation of the drug, urine routine and bacterial culture were performed every 2 to 3 days, and the results were negative for 3 consecutive times.

(2) After the clinical cure, the urine routine and bacterial culture are reviewed once or twice a month, and the results are negative for six months in a row.

(3) Recurrence refers to bacteriuria turning negative after treatment, but recurrence within 6 weeks after stopping the drug, and the pathogenic bacteria are exactly the same as the previous infection. Common causes of recurrence are: urinary tract dysfunction caused by abnormal urinary tract anatomy or function. Should actively remove the obstruction and correct anatomical abnormalities. If it cannot be corrected, choose the appropriate antibiotic for 6 weeks according to the sensitivity of the drug. Improper selection of antibiotics or insufficient treatment course. Drugs were selected based on drug sensitivity and treated for 4 weeks. Scar formation, poor blood supply and insufficient antibacterial concentration in the lesion. Large doses of bactericidal antibiotics such as cephalosporins and ampicillin can be used for 6 weeks.

(4) Bacterial urine turned negative after re- treatment, and two different bacterial infections, that is, re-infection, occurred within 6 weeks after discontinuation. It can be treated according to the treatment method of the first episode, and prevention is emphasized. At the same time, the presence of susceptible factors should be thoroughly checked and removed.

Prevention of chronic pyelonephritis

Strengthen your physique and improve your defenses. Actively treat susceptible factors such as diabetes, kidney stones and urinary tract obstruction. Reduce urinary catheterization and urinary tract device operation. Pay attention to clean the vulva. Women who have recurrence related to sexual life, urinate after sex, and take compound sulfamethoxazole orally once. Menopause can take 1 to 2 mg of nilestriol, 1 to 2 times a month, which can enhance local resistance.