Chronic pyelonephritis in the elderly

Introduction to chronic pyelonephritis in the elderly Urinary tract infection is a common disease in the elderly, and pyelonephritis is an important clinical type in urinary tract infection. It is a infection of the renal pelvis and renal parenchyma caused directly by bacteria (very few fungi, viruses, protozoa, etc.). Sexual inflammation, pyelonephritis multiple episodes or prolonged unhealed disease, the course of disease for more than 6 months, and there are renal pelvis and renal pelvis deformation, narrowing, the size of the two kidneys, the shape of the uneven or the tubular function continues to decline can diagnose chronic Pyelonephritis, the course of the disease is not clear, and patients with renal dysfunction after acute symptom control can also be diagnosed as chronic. Some scholars reported 181 cases of chronic pyelonephritis, only 11% have an acute history. basic knowledge The proportion of sickness: 0.01% Susceptible people: the elderly Mode of infection: non-infectious Complications: anemia, renal failure, hypertension, proteinuria

Causes of chronic pyelonephritis in the elderly

Decreased immune function (20%):

Insufficient resistance to infection, which plays an important role in the pathogenesis of urinary tract infections, the responsiveness of the elderly to stress is reduced, and the incidence of malnutrition (such as vitamin or zinc deficiency) is high, which may lead to cellular immune responses in the elderly. The cause of decline or delay, polymorphonuclear leukocyte function may have a more direct relationship with the defense of urinary tract infections. The elderly with diabetes have intermittent abnormalities in cell function, and patients with myeloproliferative and lymphoproliferative diseases have Persistent abnormalities have been found to reduce circulating IgM levels in the elderly. The level of antibodies produced by the elderly to a variety of vaccines is generally lower than that of young people, plus a normal sterile urinary system containing only a small amount of immunoglobulin ( IgA), macrophages and phagocytic cells, so the resistance to bacterial invasion is very low, so not only the urinary system is prone to infection, difficult to cure, and often recurrent, long-term prolongation, has become one of the important reasons for the induction of renal failure.

Various chronic diseases (20%):

Increase the incidence of chronic pyelonephritis, neurological diseases such as stroke and senile dementia patients with poor personal hygiene, and easily lead to incontinence, perineal pollution increases the incidence of bacteriuria in older women, the incidence of diabetic pyelonephritis is higher The cause may be hyperglycemia-related polymorphonuclear leukocyte dysfunction, recurrent vaginitis and bladder insufficiency. Intrarenal infection in patients with chronic kidney disease may be related to local defense defects in the kidney itself.

Physiological hunger decline (20%):

To this end, drinking water is reduced, while the elderly often abuse painkillers due to illness, non-sterol anti-inflammatory drugs, etc., easily lead to chronic pyelonephritis and chronic interstitial nephritis.

Pathogenesis

The disease is an infectious kidney disease caused directly by bacteria. In recent years, there is also an immune reaction that is thought to be caused by bacterial antigen, which may be involved in the occurrence and development of chronic pyelonephritis.

Pathogenic bacteria

Escherichia coli, Proteus most, followed by E. coli, Staphylococcus, Streptococcus faecalis, Alcaligenes faecalis, Pseudomonas aeruginosa, occasionally anaerobic bacteria, fungi, viruses and protozoal infections, pathogens in the early stages of infection Often single, but chronic or secondary to urinary tract obstruction, mixed infection is more common, the urinary tract infection pathogens obtained in society and hospitals are significantly different, clinical Pseudomonas aeruginosa, staphylococcus Infections are more common in patients with a history of urinary tract examinations or long-term indwelling catheters. Diabetes and immune function are often associated with urinary tract fungal infections. Many Candida albicans infections are often caused by blood. In recent years, cephalosporins have been used. Widely used, the infection caused by E. coli has a downward trend, while Pseudomonas aeruginosa, Enterococcus and Gram-positive cocci infections have an upward trend, L-type bacterial infections also increase significantly, and the basis of urinary structure and function abnormalities On the other hand, some non-pathogenic bacteria and non-urinary pathogens can also cause urinary tract infections. Cryptococcus neoformans mainly invade the kidneys and prostate, in the presence of pyelonephritis In the disease mechanism, the virulence of bacteria also plays an important role. The virulence of Escherichia coli isolated from the urine of patients with pyelonephritis is stronger than that of Escherichia coli isolated from the urine of patients with asymptomatic bacteriuria. The performance is as follows: the bacteria contains a large amount of K antigen; the ability to attach to the urothelial cells (adhesion) is stronger; the surface of the bacteria has cilia, and thereby adheres to the corresponding receptor of the urothelial cells, without following the urine Excreted from the body, and colonization in the urinary tract causes infection, for which the adhesion of bacteria is considered to be an important factor in its toxicity.

2. Route of infection

(1) Ascending infection: the most common infection route, when the body's resistance is reduced or the urinary tract mucosal damage (such as high concentration of urine, menstrual period, after sex life, etc.), or the invasive bacteria are highly toxic, sticking to When the urinary tract mucosa and the ability to spread upwards, the bacteria in the urethra and its surrounding areas are prone to invade the urinary tract and cause pyelonephritis. Because the female urethra is much shorter than the male, and the urethral opening is close to the anus, it is often caused by fecal bacteria. Pollution, it is more prone to disease, bacteria along the urinary tract first into the renal pelvis and kidney sputum caused inflammation, and then through the renal pelvis, nipple, renal tubules up to the renal parenchyma.

(2) blood infection: less common, in the body's immune function is low or some trigger factors, the body's chronic infections (such as tonsillitis, sinusitis, caries or skin infections, etc.) bacteria invade the blood circulation to the kidneys In pyelonephritis, when the blood is infected, the bacteria first reach the renal cortex, and a small abscess is formed there, and then spreads down the renal tubule to the renal papilla and renal pelvis, and the renal pelvis mucosa, but the inflammation can also be slightly damaged from the kidney nipple. The nipple collection tube (such as crystallization of urine damage, etc.) begins and then spreads up and down.

(3) Lymphatic infection: It is rare. It is believed that the lymphatic vessels of the lower abdomen and pelvic organs have most traffic branches with lymphatic vessels around the kidney. There is also lymphatic communication between the ascending colon and the right kidney. Therefore, when the pelvic organs are inflamed, In appendicitis and colitis, bacteria can cause pyelonephritis through the lymphatics.

(4) Directly invaded by adjacent organs.

3. Susceptibility factors

Older people are more susceptible to many diseases, and the interaction of multiple factors makes older people susceptible to urinary tract infections.

4. Anatomical factors and urinary physiology abnormalities

Often associated with chronic pyelonephritis:

(1) The renal tubular function and bladder function of the elderly decrease with age, which also affects urinary function. These are the participating factors of high incidence of urinary tract infection in the elderly, recurrent and difficult to cure, and the renal tubular function of the elderly is reduced. It shows a decrease in water, sodium transport function and urine concentrating ability. The radioimmunoassay method measures the increase of urinary 2-MG content. After excluding other various diseases, it can sensitively reflect the decline of renal tubular function in the elderly. The elderly have a decreased metabolism of drugs excreted by the kidneys, which may cause renal tubular drug poisoning and chemical damage. On this basis, it is more likely to cause upper urinary tract infection, and the sensitivity of urinary tract epithelial cells to bacteria adhesion is increased. It is related to changes in estrogen levels.

(2) local structural changes, such as high-grade elderly renal cysts, kidney stones, especially the formation of diverticulum or cysts in the distal convoluted tubules and collecting ducts, as well as the relative ischemic state of the elderly kidney and bladder mucosa, pelvic muscle relaxation, habit Sexual constipation, etc., can further aggravate the bad blood circulation of the local mucosa and reduce the defense mechanism of the urinary tract mucosa.

(3) Urinary outflow obstruction and bladder emptying in the elderly are common causes of urinary tract infection. The causes are urethral stricture (caused by instrument examination or surgery), bladder bulging, urethral prolapse, uterine dislocation caused by pelvic muscle relaxation. Dangling, benign prostatic hyperplasia, bladder diverticulum, bladder tumor, the incidence of neurogenic bladder or bladder is increased at the same time, which makes the residual urine in the bladder increase, which affects the mechanical washing effect. The flushing effect is the most effective mechanism for the bladder to resist infection. Urine accumulation caused by vacancies causes bacteria to multiply, resulting in local infections.

Bacteria harboring urinary tract or prostatic calculi (usually composed of ammonium magnesium phosphate or calcium phosphate) are often difficult to eradicate. The infection is prone to recurrence. Urinary tract obstruction causes septicemia and renal parenchymal destruction. Adult ureteral reflux often suggests Congenital malformation or severe bladder filling, reflux causes infection from the lower urinary tract into the upper urinary tract and kidney. The renal medulla is particularly prone to infection. The medulla hypertonic inactivates C4, prevents inflammation and inhibits granulocyte chemotaxis. Sexual and phagocytosis, colonic fistula perforation or colon cancer caused by colonic bladder spasm is also the cause of urinary tract infections.

Catheterization is more common in the elderly. It is used for diagnosis and treatment. Patients who use a closed drainage system to indwell catheterization have a 50% risk of bacteriuria on the 10th day. Over time, bacteriuria occurs in all cases.

In chronic pyelonephritis, the shape of the kidney is reduced, the surface of the surface is rough, the unevenness is formed, the cortex and medulla are thinned, the renal pelvis, the renal pelvis and the nipple are scar-formed, and the renal pelvis and the renal pelvis are deformed due to scar contraction. Narrow, inflammatory lesions and fibrous tissue hyperplasia in the renal parenchyma, microscopic tubular epithelial cells atrophy, degeneration, and different degrees of fibrosis around the renal tubules. With the development of inflammation, fibrous tissue increases, renal parenchymal damage increases, and eventually becomes "Pyelonephritis and pyknosis", clinical renal insufficiency.

Elderly chronic pyelonephritis prevention

Third-level prevention

Chronic pyelonephritis is an important disease leading to the death of the elderly, so it should pay attention to its prevention work. The so-called early prevention, also known as "primary prevention" refers to prevention before the occurrence of chronic pyelonephritis, should drink plenty of water, diet Should be light, avoid fatty greasy dry, spicy products, pay attention to the perineal health, pay attention to proper rest, avoid urinating, indulge in overwork, to enhance physical fitness, improve the body's defense ability, is an important aspect of prevention of this disease, second Level prevention, that is, "three early" (early detection, early diagnosis, early treatment) prevention, through epidemiological screening countermeasures, sound prevention network, annual urine routine, urine culture, kidney ultrasound examination, third level Prevention, also known as rehabilitation therapy, should be actively treated for chronic pyelonephritis that has already occurred, preventing it from developing into chronic renal failure. For frequent recurrence, low-dose long-term bacteriostatic treatment can be used.

2. Risk factors and interventions

At the same time of antibacterial treatment, especially for patients with poor efficacy or frequent recurrence, it is necessary to find and remove the susceptibility factors, and actively seek and remove inflammatory lesions, such as male prostatitis, female vaginitis and cervicitis, reducing unnecessary Catheterization and urinary tract device operation, if it is necessary to retain catheterization, preventive application of antibacterial drugs, women who are related to sexual life, should urinate after sex, and take a compound sulfamethoxazole, Menopausal intravaginal nylestriol 1 ~ 2mg, 1 ~ 2 times / d, to enhance local resistance, bladder-ureteral reflux patients, to develop 2 urination habits, that is, every few urination after a few minutes, then Repeat urination once, eliminate various incentives such as diabetes, relieve poor urine flow, urinary tract obstruction, and correct renal and urinary tract malformations.

Chronic pyelonephritis complications in the elderly Complications anemia renal failure hypertension proteinuria

Can be complicated by anemia, electrolyte imbalance, advanced glomerular sclerosis, renal failure and so on.

Elderly chronic pyelonephritis symptoms common symptoms chronic renal insufficiency proteinuria fatigue hematuria polyuria loss of appetite bacteria urinary back acid renal dysfunction edema

The clinical manifestations of chronic pyelonephritis in the elderly are mostly atypical, often complicated and diverse. In severe cases, severe symptoms may be similar to acute pyelonephritis, which may have obvious symptoms of systemic infection. The common symptoms are general malaise and weight loss. , low fever, urinary incontinence, dysuria, urinary retention, polyuria, nocturia, etc., a small number of patients with low back pain, abdominal pain or renal colic, light can be asymptomatic, only urine changes, individual patients only have high blood pressure Chronic pyelonephritis should be suspected in patients with chronic bacteriuria when there is urinary obstruction, indwelling catheterization or neurogenic bladder. The following 5 types are common:

1. Relapsing type: often with acute attacks, symptoms of systemic infection, local urinary tract manifestations and changes in urine are similar to acute pyelonephritis.

2. Low-heat type: The main performance is long-term low fever, which may be associated with fatigue, backache, loss of appetite and weight loss.

3. Hematuria type: can be hematuria as the main performance, microscopic or gross hematuria, with low back pain, backache and urinary tract irritation.

4. Concealed type: no systemic or local symptoms, only urine changes, urinary bacteria culture can be positive, also known as asymptomatic bacteriuria.

5. Hypertension: Hypertension occurs in the course of the disease, and even develops into hypertensive hypertension, often accompanied by anemia, but no obvious proteinuria and edema.

In addition to the above types, a small number of cases can still be characterized by loss of sodium nephropathy, potassium loss nephropathy, renal tubular acidosis and chronic renal insufficiency.

Elderly pyelonephritis often has urinary retention factors, easy to cause urinary tract sepsis, should be vigilant, Posito et al reported 100 cases of senile sepsis, 34% caused by pyelonephritis, of which only 7 cases have urinary tract irritation, 8 cases have History of urinary intubation, Tunn et al reported that 55% of Gram-negative bacilli sepsis is from urinary tract infection, urinary tract sepsis is easy to have shock, and the mortality rate is very high.

Chronic pyelonephritis is relatively well preserved compared with early renal dysfunction and GFR. Since the bacteria in the medulla often cause a wide range of inflammatory reactions, eventually scars and tubular structures are distorted, which interferes with the medullary transport mechanism. These changes can cause Polyuria, nocturia, renal diabetes insipidus and electrolyte perforation, lesions involving the cortex, and extensive renal scar formation leading to renal failure.

Recurrence is a clinical feature of pyelonephritis. Recurrence can be recurrence or reinfection of the original disease. The nature of the two is different, and the treatment and prognosis are different. It must be distinguished. Recurrence refers to pyelonephritis that is not cured, but the condition is temporarily relieved. Some factors cause the latent bacteria to cause inflammation and the disease; re-infection is the original disease has been cured, the bacteria have been destroyed, caused by the invasion of new pathogenic bacteria.

The results of urinary bacterial culture are consistent with true bacterial urinary or pyelonephritis for more than half a year. One of the following conditions can be diagnosed as chronic pyelonephritis: imaging examination reveals that the renal pelvis is deformed and narrowed; the two kidneys vary in size and the kidney surface is uneven. Uneven; renal tubular function has sustained damage.

Examination of chronic pyelonephritis in the elderly

Urine routine

Microscopic examination of leukocytosis, if you see white blood cells (or pus cells) cast, it suggests that the lesions in the upper urinary tract, red blood cells can also increase, hematuria type even for gross hematuria, urine protein can increase, but generally <2.0g / d, Mostly small protein, when the renal tubular function is impaired, the urine specific gravity may decrease, and the morning urine pH will increase.

Increased urinary leukocyte excretion suggests urinary tract inflammation, which is also important in diagnosis. The incidence of pyuria in asymptomatic bacteriuria is about 37%, leukocyte excretion >5/mm3 is abnormal, and pyuria and bacteriuria are extremely significant. Sexuality can be used as the initial screening method. The sensitivity of leukocyte esterase test paper to predicting microscopic bacteriuria and positive urine culture is 100%. For example, combined with microscopic pyuria and bacteriuria, the specificity is also 100%.

Treated with antibiotics or chemotherapy drugs, aseptic pyuria will soon appear, aseptic pyuria is also a phenomenon of kidney tuberculosis, stones, analgesic abuse, a small number of aerobic and anaerobic infections, urinary tract injuries such as chlamydia urethritis Aseptic pyuria can also be seen in glomerulonephritis and kidney disease.

Urinary tract infections without pyuria are seen in leukopenia caused by drugs and regenerative disorders, and distal infectious diseases of the renal collecting system (such as renal cortical abscess), occasionally in obstructive uropathy.

White blood cell urine is not a constant feature of urinary tract infection. The white blood cell count of urine samples varies several times. The single urine sample cannot detect white blood cells should not be regarded as evidence of sterile urine. Pyuria depends on urine flow and urine pH. The urine bacteria count can also be different within one day. Generally speaking, it is advisable to check the morning urine specimen.

Leukocyte cast is a reliable evidence of inflammatory disease of the upper urinary tract, but it is not unique to infections like the granular cast. These casts are often not found in active pyelonephritis, and fresh urine specimens must be used for tube counts.

Microscopic hematuria is not a reliable evidence of bacterial infection. No proteinuria can exclude urinary tract infection. Most urinary tract infection patients have urinary protein excretion of less than 2.0g/24h.

2. Urine bacteria test

Significant bacteriuria refers to the bladder urine obtained directly by the diameter (bladder puncture) confirmed by bacterial reproduction (regardless of the count) or the mid-stage urine culture count is greater than 105/ml, when there is urinary tract obstruction, frequent urination, improper use of specimens and use The antibiotics can affect the culture results. However, if the same results are obtained for three consecutive times, the diagnostic value will increase from 80% to more than 95%. The evaluation criteria for quantitative culture of urine bacteria is that the number of bacteria in the urine is greater than 105. /ml is positive, less than 104/ml is pollution, between 104 ~ 105 / ml need to be reviewed or combined with clinical comprehensive consideration to make a diagnosis, but the cocci reproduction rate is slow, the number of bacteria containing bacteria is 103 ~ 104 / ml, has Diagnostic significance, according to clinical needs, in addition to the cultivation of common bacteria, it is highly suspected that the original pulp type strain can be used for high-permeability culture, which can improve the positive rate of L-type strain culture, and the chronic pyelonephritis which is positive for multiple urine common bacteria culture. Diagnosis is of great significance. L-type bacteria are bacteria without solid cell walls. When bacteria come into contact with substances that damage their surface, such as antibiotics or antibody-complement-lysozyme, they can be converted into L-type bacteria, and the high tension of renal medulla. The state is conducive to its survival, the L-type bacteria have low virulence, and the virulence can be restored to normal after conversion to normal bacteria. The necessary fashion can be used for anaerobic culture, fungal culture, and drug sensitivity test should be used to guide clinical practice. Select antibacterial drugs, do not centrifuge urine. If you have a microscopic examination, you will find that there is one bacteria in each high-power microscope. It is also 100% specific and 78% sensitive for judging meaningful bacteriuria. This method is simple and has a high positive rate. Can be determined to be bacillus or cocci, is Gram positive or negative, which is of great value for timely selection of effective drug treatment.

The method of urine specimens directly affects the accuracy of diagnosis. The first mid-stage urinary still has the preferred method in the morning, followed by catheterization and pubic bladder puncture to take urine, but 40% to 60% of the elderly have The urinary incontinence of different severity can be collected by the outer cannula. The method has 100% sensitivity and 94% specificity compared with the catheterization method. The specimen should be stored in the refrigerator without being cultured immediately after the specimen is taken. The bacteria can be proliferated by leaving the bacteria for more than 2 hours at room temperature.

3. Urine cell count

In recent years, more than 1h urinary cell counting method has been applied. The criterion is that the white blood cell is 300,000/h positive, less than 200,000/h is negative, and between 200,000 and 300,000/h is combined with clinical judgment. Urine cell count is often used in this disease. In the chronic phase, especially in the urine routine, there was no obvious abnormality. There were no positive results in multiple urine cultures, and there was no specific clinical manifestation.

4. Blood routine examination

In the acute phase, white blood cell counts and neutrophils can be increased, and chronic red blood cell counts and hemoglobin can be slightly reduced.

5. Serological examination

More clinically significant:

1 urine antibody-encapsulated bacteria examination, under the fluoroscopy to observe urinary bacteria treated with fluorescein-labeled anti-human protein antibody, if the surface is coated with antibodies, most of them belong to pyelonephritis, which is helpful for the diagnosis of urinary tract infection.

2 Identification of the serotype of urinary bacteria, help to distinguish the nature of recurrent pyelonephritis, if recurrence and the previous blood type is the same recurrence, and 2 times for different serotypes are re-infection.

6. Renal function test

Persistent functional impairment can occur in the chronic phase:

1 renal dysfunction decreased, such as nocturia, morning urine penetration decreased.

2 renal acidification decreased, such as morning urine pH increased, urine HCO3- increased, urine NH4 + decreased.

3 glomerular filtration dysfunction such as decreased endogenous creatinine clearance, blood urea nitrogen, creatinine and so on.

7. X-ray inspection

For chronic or long-term treatment, urinary tract film, venous pyelography, retrograde pyelography, urinary ureter ureteroscopy may be performed as needed to check for obstruction, calculi, ureteral stricture or compression, renal ptosis, urinary system congenital Sexual malformation and vesicoureteral reflux phenomenon, in addition, can also understand the renal pelvis, renal pelvis morphology and function, in order to distinguish with renal tuberculosis, renal tumor, chronic pyelonephritis, renal pelvis is slightly dilated or sputum, and can be scarred Malformation, renal insufficiency need to use 2 times or 3 times dose of iodine contrast agent for rapid intravenous infusion, this test may aggravate the further deterioration of renal function, please pay attention to and take multiple films to achieve satisfactory results of angiography, renal angiography It can be shown that the small blood vessels of chronic pyelonephritis have different degrees of distortion, and if necessary, can be used for renal CT scan or MRI scan to exclude other kidney diseases.

8. Isotope kidney chart examination

Can understand renal function, urinary tract obstruction, vesicoureteral reflux and residual bladder urine, acute pyelonephritis, the renal pattern is characterized by peak shift, the secretion segment appears to be delayed by 0.5 to 1.0min, the excretion segment declines slowly; chronic pyelonephritis The slope of the secretory segment decreased, the peak became blunt or broadened and moved back, and the beginning of the excretion segment was delayed, parabolic, but the above changes were not significantly specific.

9. Ultrasound examination

It is currently the most widely used and simplest method. It can screen urinary tract dysplasia, congenital malformation, polycystic kidney disease, renal artery stenosis caused by uneven kidney size, stones, severe hydronephrosis, tumor and prostate diseases, etc. .

Diagnosis and differential diagnosis of chronic pyelonephritis in the elderly

Differential diagnosis

The disease still needs to be identified with the following diseases:

Kidney tuberculosis

The disease may have fever, urinary tract irritation and pyuria and other symptoms, similar to pyelonephritis, but the symptoms of bladder irritation during renal tuberculosis are very obvious and lasting, urinary sediment smear can find acid-fast bacilli, urinary bacteria culture tuberculosis positive, etc. Identification, if necessary, for intravenous pyelography, such as the discovery of renal parenchymal destructive defects can help diagnose kidney tuberculosis.

2. Chronic glomerulonephritis

If there is edema, a large amount of proteinuria is not difficult to identify, the urinary protein content of pyelonephritis is generally below 1 ~ 2g / d, if more than 3g are mostly glomerular lesions, but this disease and occult glomerulonephritis is more difficult Identification, the latter has more red blood cells in the urine routine, and pyelonephritis is mainly white blood cells. In addition, urine culture, long-term observation of patients with low fever, frequent urination and other symptoms can also help identify, end nephritis secondary urinary tract infection, identification Difficulties, at this time you can ask the medical history in detail, combined with clinical characteristics to analyze.

3. Lower urinary tract infection

The treatment of upper and lower urinary tract infections is different from the prognosis. Therefore, the diagnosis of location is very important. When the systemic symptoms such as high fever of pyelonephritis and low back pain, renal pain such as kidney pain are not obvious, the clinical susceptibility to lower urinary tract infection, urine Sampling antibody-coated bacteria positive is helpful for diagnosing pyelonephritis. If necessary, it can be used for bladder irrigation and sterilization. If the bladder is sterilized for 100 minutes, the number of bladder urinary bacteria is small, suggesting cystitis, such as the number of bacteria before and after sterilization. Similar, it is pyelonephritis.

Clinically, there is a kind of urethral syndrome, which occurs in middle-aged women. It is mainly characterized by frequent urination and poor urination. It is often mistaken for atypical chronic pyelonephritis and long-term blind application of antibiotics or even adverse consequences. Identification, urinary white blood cells can also be increased in the intrinsic patients, but negative urine culture can be identified.

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