postpartum urinary tract infection

Introduction

Introduction to postpartum urinary tract infection Postpartum urinary tract infection is a common complication after childbirth. Urinary tract infection (UTI) is a disease caused by various pathogens invading the urinary system. According to the pathogen type can be divided into bacterial UTI, fungal UTI and viral UTI; according to the infection site can be divided into upper urinary tract infection (pyelonephritis, ureteritis) and lower urinary tract infection (cystitis, urethritis; according to clinical Symptoms can be divided into symptomatic UTI and asymptomatic UT; according to the presence or absence of urinary tract abnormalities (such as obstruction, calculus, malformation, vesicoureteral reflux, etc.) are further divided into complex UTI and non-complex UTI. basic knowledge The proportion of illness: 0.12% Susceptible population: multiple catheterization and pelvic urethra are more congested during childbirth, and women's resistance during puerperium is reduced, so it is frequent. Mode of infection: non-infectious Complications: septic shock Pregnancy with acute pyelonephritis Anemia Pulmonary edema Hypotension

Cause

Causes of postpartum urinary tract infection

(1) Causes of the disease

UTI more than 95% caused by a single bacterium, Gram-negative Enterobacter is the main pathogen, of which Escherichia coli is the most common, about 90% of outpatients and 50% of hospitalized patients are Escherichia coli, more common in Asymptomatic bacteriuria, non-complex UTI and primary UTI, Klebsiella pneumoniae, Pseudomonas and Proteus infections are common in recurrent UTI, and nearly 10% to 15% of UTI can also be caused by Gram-positive bacteria Caused by Staphylococcus and Enterococcus faecalis, among which Staphylococcus aureus is an important cause of acute UTI in women (especially young women). A survey of female UTI patients with symptomatic UTI found that the infection rate is second only to the large intestine. Hepatitis, fungal infections (mainly Candida) occur in indwelling catheters, diabetes, patients with broad-spectrum antibiotics or immunosuppressive agents, some viral infections can involve the urinary tract, clinically asymptomatic, but adenovirus type II Infection can cause acute hemorrhagic cystitis in school-age children. Mycoplasma infection is rare, but it can cause acute urethral syndrome. Mixed infections of various pathogens are only found in long-term placement of catheters, urethra (Stone or tumor), with recurrent urinary retention inspection equipment, and urethra - vagina (intestinal) fistula the patient.

(two) pathogenesis

Due to pregnancy:

1 ureter, renal pelvis and renal pelvis expansion;

2 The incidence of vesicoureteral reflux is increased, and reflux can cause bacteria in the bladder to rise with the urine;

3 The amount of carbohydrates in the urine increases during pregnancy, which becomes a good medium for bacteria and contributes to the growth of bacteria;

4 In the third trimester, the fetal head compresses the lower end of the bladder and the ureter, resulting in poor urination. Therefore, pregnant women have susceptibility to urinary tract infection. In addition, after the delivery, the urethra may be damaged. During the delivery process, the catheter is inserted multiple times, and the pelvic urethra is inserted. More congestive, women's resistance during puerperium is reduced, easy to cause bacterial invasion, it is more likely to occur infection, the pathogen is mainly Escherichia coli, followed by streptococcus and staphylococcus, clinically often mixed infection.

Prevention

Postpartum urinary tract infection prevention

For patients with chronic pyelonephritis, it is necessary to enhance physical fitness, improve the body's defense ability, eliminate various predisposing factors such as diabetes, kidney stones and urinary tract obstruction, and actively seek and remove inflammatory lesions, paraurethralitis, vaginitis and cervicitis. Reduce unnecessary catheterization and urinary tract device operation, such as the need to retain catheterization should be preventive application of antibacterial drugs, female recurrence and sexual life related, should urinate after sexual life, and take a dose of SMZ-TMP, pregnant During the period and menstrual period, attention should be paid to the cleanliness of the vulva.

Complication

Postpartum urinary tract infection complications Complications septic shock pregnancy with acute pyelonephritis anemia pulmonary edema hypotension

1. Although acute cystitis does not have complications, it can be caused by ascending infection, which quickly affects the upper urinary tract. 40% of patients with acute pyelonephritis during pregnancy have symptoms of lower urinary tract infection before onset.

2. Pregnancy with acute pyelonephritis can lead to life-threatening complications, dysfunction of multiple organ systems, including:

(1) endotoxemia and septic shock: clinical signs of excessive temperature drop (less than 35 ° C) and other adverse signs, often a precursor to endotoxemia and septic shock aura.

(2) Anemia and thrombocytopenia: Escherichia coli endotoxin contains lipopolysaccharide which destroys red blood cells and causes anemia.

(3) Renal dysfunction: glomerular filtration rate decreased, and creatinine clearance decreased.

(4) Lung damage: endotoxin damages the alveoli and causes pulmonary edema (respiration dysfunction and even adult dyspnea syndrome).

Symptom

Symptoms of postpartum urinary tract infections Common symptoms Urinary pain bacteria Urinary urgency Urinary frequency Bladder stimulation Postpartum body aches Pain Postpartum fever High fever Abdominal pain Lower abdominal pain

1. Pyelonephritis has chills and fever after childbirth, body temperature can reach above 39 °C, there may be reflex vomiting, low back pain, more common on the right side, pain radiates along the ureter to the bladder, so patients sometimes complain of lower abdominal pain, and some have Bladder irritation symptoms, such as frequent urination, urgency, dysuria, etc., there is tenderness or sputum pain in the kidney area, and a large amount of bacteriuria can be found in laboratory tests.

2. The clinical manifestations of cystitis in the puerperic period are basically the same as those in general non-pregnancy cystitis. There are frequent urination, dysuria, urgency, fever, frequent urination, dysuria, urgency, fever, but urinary pain. Symptoms are more obvious, urgency symptoms are milder, which may be related to low postpartum bladder tension and poor sensitivity.

Examine

Postpartum urinary tract infection check

In the acute phase, there may be acute inflammatory manifestations, such as increased white blood cell count and increased neutrophil percentage, but the following tests are more meaningful for diagnosis.

1. Urine routine examination is the easiest and most reliable test method. It is advisable to leave the first urine in the morning for testing. More than 5 (>5/Hp) white blood cells in each high power field are called pyuria, about 96% or more. Patients with symptomatic UTI may have pyuria. Direct microscopy is unreliable. The detection of leukocytic excretion rate is more accurate, but it is too cumbersome. It is now advocated to use leukocyte lipase test. When white blood cells exceed 10 per ml, it is positive. Sexuality and specificity are 75% to 96% and 94% to 98%, respectively. In addition to pyuria, acute urinary tract infections can often be found in leukocyte casts, bacteriuria, sometimes with microscopic hematuria or gross hematuria, especially cloth. When there is infection with Brucella, Nocardia and actinomycetes (including Mycobacterium tuberculosis), occasionally micro-proteinuria, if there is more proteinuria, it indicates glomerular involvement.

2. Urinary bacteriological examination More than 95% of UTI is caused by Gram-negative bacteria. In sexually active women, saprophytic staphylococcus and Enterococcus faecalis can occur, while some bacteria that are parasitic in the urethra, skin and vagina, such as Staphylococcus epidermidis, Lactobacillus, anaerobic bacteria, coryneform bacteria (diphtheria bacilli), etc., rarely cause UTI, except for special cases, there are more than two kinds of bacteria in the urine culture, indicating that the specimens are contaminated. In the past, the number of colonies in the middle of clean culture was >100,000 per ml. It has clinical significance, and it is caused by pollution of <10000/ml per ml. It is now found that many UTI patients have low colony counts, even 100/ml. The reasons may include: acute urethral syndrome; saprophytic staphylococcus and candida infection. Antibiotic treatment has begun; rapid diuresis; extreme acidification of urine; urinary tract obstruction; extraluminal infection, etc., the American Society of Infectious Diseases recommends the following criteria: symptoms of lower urinary tract infection, colony count 1000/ml; pyelonephritis Symptoms, colony count 10000 / ml can consider infection, the sensitivity and specificity of the former are 80% and 90%, the latter are 95%.

3. UTI positioning examination includes invasive examination and non-invasive examination. Bilateral ureteral catheterization method is highly accurate, but urine must be taken through cystoscopy or percutaneous puncture, so it is not commonly used for traumatic examination. It is simple and easy to use, clinically used, and the accuracy is >90%. The specific method is to inject 20ml of 2% neomycin solution into the catheter to sterilize the bladder, then rinse it with salt water, then collect the urine flowing into the bladder for culture. Take the urine specimen once every 10 minutes for 3 times. If it is cystitis, the bacterial culture should be negative; if it is pyelonephritis, it is positive, and the number of colonies rises, the non-invasive test includes urine concentration function. Urine enzyme and immune response test, acute and chronic pyelonephritis often accompanied by tubular dysfunction, but this test is not sensitive enough, can not be used as a routine examination, some patients with pyelonephritis urinary lactate dehydrogenase or N-acetyl--D amino grape Enzymes can be elevated, but lack specificity. Urine enzymes that have been able to contribute to UTI localization are still under investigation. Recently, more applications have been made to detect antibodies in the urine, and bacteria from the kidneys have antibody wraps. The bacteria from the bladder are not coated with antibodies, so they can be used to distinguish upper and lower urinary tract infections, but the accuracy is only 33%, vaginal or rectal flora contamination, large amounts of proteinuria or infection invading the urethral epithelium (such as prostatitis, hemorrhagic cystitis) Others can lead to false positives, 16% to 38% of adults with acute pyelonephritis and most children can have false negatives, so it is not routinely used. In addition, urine 2 microglobulin determination also helps identify upper and lower urinary tract infections. Upper urinary tract infection may affect the reabsorption of small molecule proteins by renal tubules, urinary 2 microglobulin is elevated, and urinary 2 microglobulin is not elevated in lower urinary tract infection. It has been reported in the literature that serum C-reactive protein is in pyelonephritis. The time is obviously increased, and can reflect the therapeutic effect, but the acute cystitis does not increase, but the C-reactive protein can also be increased due to other infections, thus affecting the reliability of the test.

4. X-ray examination Because acute urinary tract infection itself is prone to vesicoureteral reflux, intravenous or retrograde pyelography should be performed 4 to 8 weeks after infection is eliminated. Acute pyelonephritis and uncomplicated recurrent UTI are not advocated. Routine pyelography, for patients with chronic or long-term treatment, urinary tract stenosis, intravenous pyelography, retrograde pyelography and urinary ureteroscopy can be performed as needed to check for obstruction, calculi, ureteral stricture or compression, kidney Drooping, urinary congenital 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, kidney tumors, renal angiography can show small blood vessels of chronic pyelonephritis Different degrees of distortion, if necessary, can do a kidney CT scan or magnetic resonance scan to rule out other kidney diseases.

5. Radionuclide renal examination can understand the renal function, urinary tract obstruction, vesicoureteral reflux and bladder residual urine. The renal pattern of acute pyelonephritis is characterized by a peak shift, and the secretory segment is delayed by 0.5-1.0 min. The excretion segment decreased slowly; the slope of the secretory segment of chronic pyelonephritis decreased, the peak became blunt or widened and moved backward, and the beginning of the excretory segment was delayed, parabolic, but the above changes were not significantly specific.

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

Diagnosis

Diagnosis and diagnosis of postpartum urinary tract infection

Acute pyelonephritis usually has typical symptoms and abnormal urine findings. It is not difficult to diagnose. If there is only high fever and the urinary tract symptoms are not obvious, it should be differentiated from various febrile diseases. Abdominal pain and low back pain should be associated with cholecystitis and appendicitis. , pelvic inflammatory disease, perirenal abscess and other identification, generally after repeated urine tests can be diagnosed, the urinary tract symptoms of chronic pyelonephritis are not obvious, no significant changes in urine routine or intermittent urine abnormalities, easy to be misdiagnosed, in women Anyone with unexplained fever, backache, fatigue, mild urinary tract symptoms should consider the possibility of this disease, repeated examination of urine routine and culture to find evidence, chronic pyelonephritis with hypertension and essential hypertension Identification, in addition, must be identified with the following diseases.

1. Kidney tuberculosis Urinary tract tract tuberculosis is often accompanied by, is the most common extrapulmonary tuberculosis, multiple bloodline infections, acute fever (low fever), night sweats, fatigue, low back pain, frequent urination, urgency, dysuria, Hematuria and other symptoms, about 20% of cases can be no clinical manifestations, also known as silent UTI, several years after the destruction of renal parenchyma, tuberculous granulomatous cheese-like changes involving the medulla and nipple area, followed by nipple necrosis, renal pelvis and renal pelvis deformation, Thinning of the cortex, occasionally involving the surrounding tissues of the kidney, impaired renal function in the late stage of renal tuberculosis, bladder contracture, X-ray examination of the lungs, detection of the prostate, epididymis and pelvic tuberculosis contribute to the diagnosis of the disease, urine test may have Hematuria (microscopic hematuria or gross hematuria) and pyuria, positive for urinary tuberculosis culture, the detection rate is more than 90%, polymerase chain reaction (PCR) can also be used for the detection of urinary tuberculosis, the positive rate is as high as 95%, but should Note false positives, and intravenous pyelography can only find more advanced cases.

2. Chronic glomerulonephritis If there is edema, a large number of proteinuria is not difficult to identify, the urinary protein content of pyelonephritis is generally below 1 ~ 2g / d, if > 3g are mostly glomerular lesions, but the disease and hidden It is difficult to identify nephritis, the latter has more red blood cells in the urine, 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, late nephritis secondary Urinary tract infection, identification is difficult, at this time can be detailed in the history of the disease, combined with clinical characteristics to analyze.

3. Prostatitis Men over 50 years old have prostatic hyperplasia, hypertrophy, catheter placement, cystoscopy, etc., susceptible to this disease, acute prostatitis in addition to chills and fever, increased total white blood cells, may have lumbosacral and Perineal pain and frequent urination, dysuria, urine examination have pus cells, and easy to be confused with acute cystitis. Chronic prostatitis is not obvious except for abnormal urine test. The number of white blood cells in prostatic fluid obtained by prostate massage is >10/HP And prostate B ultrasound helps differential diagnosis.

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