Obstructive nephropathy in the elderly

Introduction to obstructive nephropathy in the elderly Obstructive nephropathy (obstructive nephropathy) refers to obstruction of any part of the urinary tract caused by various reasons, resulting in increased pressure above the obstruction, resulting in renal parenchymal damage and dysfunction. It is one of the common causes of acute and chronic renal failure, and is a common predisposing factor for recurrent urinary tract infections. basic knowledge The proportion of the disease: the incidence of the disease in the elderly over 60 years old is about 0.08% Susceptible people: the elderly Mode of infection: non-infectious Complications: urinary retention, hematuria, renal insufficiency

Etiology of obstructive nephropathy in the elderly

(1) Causes of the disease

There are many causes of obstructive nephropathy, and there are many methods for classification. At present, most scholars advocate classification according to the cause, that is, according to the etiology of the obstruction site, it is divided into endoluminal, intramural and extraluminal.

According to different causes, the lesion can be unilateral or bilateral.

(two) pathogenesis

Obstructive nephropathy caused by any cause can lead to obstructive renal structure and functional lesions; 1 week of obstruction, intrarenal changes are reversible lesions, and glomerular filtration rate (GRF) can be restored to obstruction when obstruction is relieved 2/3; if the obstruction is relieved after 4 weeks, the GRF can only recover to 20% to 25% of the original; if the complete obstruction exceeds 4 to 6 weeks, it will cause irreversible damage to the structure and function of the kidney. Sexual obstruction, acute renal failure can occur.

In the early stage of obstruction, the renal pelvis and ureteral wall muscles compensatory hypertrophy, renal edema and hemorrhage, if the obstruction continues to exist or worsen, due to the continuous increase of intra-renal pressure, tissue compression, blood flow is reduced, leading to renal cell necrosis; 4-8 After the week, the surface was purple-blue, the volume was obviously atrophied, and the wedge-shaped congestive necrosis or ischemic scar was seen on the cut surface. The medulla was almost completely destroyed, and the cortex became thin and became a hardened ring. Under the microscope, the collecting tube, the far and near convoluted tubules were atrophied and necrotic. Chronic inflammation of the interstitial, glomerular degeneration, and the results are similar to glomerular sclerosis.

After urinary tract obstruction, urine continues to form, so that the pressure in the urinary system continues to increase, and the proximal urinary tract is dilated. When the pressure in the urinary system is close to the glomerular filtration pressure (0.8 to 1.6 kPa), the glomerular filtration The rate of passing is getting lower and lower. In the early stage, the balance of the internal environment can be maintained through a series of compensation mechanisms.

1. Renal tissue compensatory hypertrophy and hyperplasia.

2. Urine reflux absorption, the route is:

1 renal pelvis lymphatic reflux;

2 renal pelvis venous return;

3 renal pelvis renal tubular reflux.

3. Kidney confrontation balance

When one side of the kidney is stagnant and the kidney function is damaged, the contralateral normal kidney can be compensated for hypertrophy; if the hydronephrosis of the obstructed side is relieved and the renal function is restored, the hypertrophied kidney is reduced again. This phenomenon is against the balance. The obstruction time is too long, the renal tissue has been severely damaged, and its renal function is difficult to recover.

4. Renal function after obstruction

The effect of urinary tract obstruction on renal function depends mainly on the extent of the obstruction and the duration of the obstruction. The obstructive kidney can reduce the GFR through hemodynamic changes, and can directly cause the renal tubular function disorder.

Prevention of obstructive nephropathy in the elderly

For the active treatment of the cause, when the medical treatment is invalid, surgery should be performed as soon as possible.

Complications of obstructive nephropathy in the elderly Complications, urinary retention, hematuria, renal insufficiency

Common infections, urinary retention, hematuria, renal insufficiency, etc.

Symptoms of obstructive nephropathy in the elderly Common symptoms Weak ascites, hematuria, nausea, erythrocytosis, hypertension, anal sphincter, gastrointestinal symptoms, high fever

Due to the etiology, nature, location, length of time and complications of obstructive nephropathy, the clinical manifestations are more complicated.

Symptom

(1) lower urinary tract symptoms: due to urethral stricture, prostate lesions, bladder neck obstruction, neurogenic bladder, etc., often manifested in dysuria, urinary flow is fine, urinary dripping is not complete, etc., combined infection, There may be symptoms of lower urinary tract irritation and hematuria or pyuria.

(2) upper urinary tract symptoms: due to ureteral stricture, stones, blockage of blood clots or miscarriage of the ureter and other obstructive nephropathy, renal colic, hematuria, combined infection, in addition to urinary tract irritation, can be accompanied by chills, High fever and gastrointestinal symptoms.

(3) systemic symptoms: increased or decreased urine output, if there is renal insufficiency, may appear poor, nausea, vomiting, lack of energy, fatigue, lethargy.

2. Signs

(1) lower urinary tract obstruction: anterior urethral stricture, local access to the urethral hardening or scar area; prostate lesions, anal finger examination can touch the enlarged prostate; neurogenic bladder can be expressed as perineal sensation disappear, anus Sphincter relaxation, severe obstruction can reach the bladder with excessive urine retention.

(2) Upper urinary tract obstruction: the kidney in the affected side can be touched, and the kidney area is sore; the infected person can have tenderness in the abdomen; due to abdominal swelling or inflammatory mass compression, sometimes the corresponding part can be found. Block.

(3) systemic manifestations: high blood pressure, ascites can occur, a few cases can appear cherry lips (erythrocytosis).

The diagnosis of typical cases is not difficult, but the nature, location and cause of the obstruction are often determined by systematic examination. The repeated urinary tract infection or abdominal mass is the main complaint, which is easily misdiagnosed.

Medical history and signs: those with typical symptoms and signs can be diagnosed by selective screening.

Examination of obstructive nephropathy in the elderly

The following tests can be used as an objective indicator for the diagnosis of obstructive nephropathy and its extent.

Urine

Protein or cast type may appear in the urine, early urinary osmotic pressure is increased, late urine specific gravity is low and fixed, and those infected may be red, white blood cells, and urine culture can detect pathogenic bacteria.

2. Blood

When the infection is combined, the blood picture can be increased. When the bilateral obstruction is dysfunctional, there may be different degrees of anemia, blood urea nitrogen and creatinine increase, carbon dioxide binding capacity and blood calcium decrease, and blood phosphorus is increased.

Special examination: The following examinations can be used to understand the location, extent, nature and renal function of the obstruction.

1.B type ultrasound

Can understand the extent of urinary tract expansion, the size of the kidney and the size of the cortex, the presence or absence of residual urine in the bladder, the presence or absence of lumps around the urinary tract, and indirectly predict residual renal function.

2. X-ray film

X-ray abdominal plain film can help to find kidney, ureteral positive stones, understand the size of the kidney, malignant tumors and the presence or absence of bone metastases, found that spina bifida may have a neurogenic bladder.

3. Radionuclide map

Obstructive kidneys can present a typical high-level extension line, and the extent of collateral renal obstruction and unilateral renal function can be understood.

4. Intravenous pyelography and retrograde angiography

Can help to understand the location of the water, the extent, and can find negative urinary stones and space-occupying lesions.

5.CT and MRI

It can accurately diagnose the location, cause and kidney of urinary obstruction.

6. Bladder and urethra mirror

Can directly understand the existence, location, nature of lower urinary tract lesions, some patients can use this to relieve obstruction.

Diagnosis and diagnosis of obstructive nephropathy in the elderly

Clinical need for urinary tract infection, stone, prostate disease identification.

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