Postpartum urinary tract infection

　　1. Etiology

　　UTI is caused by a single bacterium in more than 95% of cases, with Gram-negative enterobacteria as the main pathogen, among which Escherichia coli is the most common, accounting for about 90% of outpatients and 50% of inpatients. Escherichia coli is more common in asymptomatic bacteriuria, non-complex UTI, and first-time UTI. Infections caused by Klebsiella pneumoniae, Pseudomonas, and Proteus are common in recurrent UTI. In recent years, 10% to 15% of UTIs can also be caused by Gram-positive bacteria, mainly Staphylococcus and Enterococcus faecalis, among which saprophytic Staphylococcus is an important cause of acute UTI in women (especially young women). A survey of symptomatic UTI patients among college students found that the infection rate is second only to Escherichia coli. Fungal infections (mainly Candida) are more common in patients with indwelling catheters, diabetes, use of broad-spectrum antibiotics or immunosuppressants. Some viral infections can affect the urinary tract, often without symptoms, but adenovirus type II infection can cause acute hemorrhagic cystitis in school-age children. Mycoplasma infection is rare but can cause acute urethritis. Mixed infections of multiple pathogens are only seen in patients with long-term indwelling catheters, urethral foreign bodies (calculi or tumors), urinary retention with repeated instrumental examination, and urethro-vaginal (intestinal) fistulas, etc.

　　2. Pathogenesis

　　Due to pregnancy: ① The ureters, renal pelvis, and renal calyces dilate; ② The incidence of vesicoureteral reflux increases, which allows bacteria in the bladder to ascend with urine; ③ The carbohydrate content in urine during pregnancy increases, becoming a good culture medium for bacteria, which promotes bacterial growth; ④ In the late pregnancy, the fetal head compresses the bladder and the lower end of the ureter, leading to dysuria, so pregnant women are susceptible to urinary tract infections. In addition, there is a possibility of urethral injury after delivery, frequent catheter insertion during labor, pelvic urethra congestion, reduced resistance of women during the postpartum period, which are easy to lead to bacterial invasion, thus making infections more likely to occur. The main pathogens are Escherichia coli, followed by Streptococcus and Staphylococcus, and clinical infections are often mixed infections.

　　1. Although acute cystitis does not usually cause complications, it can quickly involve the upper urinary tract through ascending infection. Among patients with acute pyelonephritis during pregnancy, 40% have symptoms of lower urinary tract infection before onset.

　　2. Women with acute pyelonephritis during pregnancy may develop life-threatening complications, including dysfunction of multiple organ systems such as:

　　(1) Endotoxemia and septic shock: The clinical manifestation of excessive decrease in body temperature (below 35℃) and other adverse signs often indicate the prodromal hypotension of endotoxemia and septic shock.

　　(2) Anemia and thrombocytopenia: Lipopolysaccharide contained in the endotoxin of Escherichia coli destroys red blood cells, causing anemia.

　　(3) Renal function damage: Decreased glomerular filtration rate and decreased creatinine clearance function.

　　(4) Lung damage: Endotoxin injury to alveoli leads to pulmonary edema (degree of respiratory insufficiency ranging from incomplete to adult respiratory distress syndrome).

　　1. Pyelonephritis After delivery, there may be chills and high fever, with body temperature reaching above 39℃, and reflex vomiting, lumbar pain, which is more common on the right side. The pain radiates along the ureter to the bladder, so the patient may complain of lower abdominal pain, and some may have bladder irritation symptoms such as frequent urination, urgency, and dysuria. There may be tenderness or percussion pain in the renal area. Laboratory tests may show a large amount of bacteriuria.

　　2. Cystitis The clinical manifestations of cystitis during the puerperium are basically the same as those of general non-pregnant cystitis, with symptoms such as frequent urination, dysuria, urgency, and sometimes fever. The symptoms of dysuria are more obvious, and the symptoms of urgency are relatively mild, which may be related to the low bladder tension and poor sensitivity after delivery.

　　For patients with chronic pyelonephritis, it is necessary to enhance physical fitness, improve the body's defense ability, eliminate various triggering factors such as diabetes, renal calculi, and urinary tract obstruction, actively seek and remove inflammatory foci, paraurethral glanditis, vaginitis, and cervicitis, reduce unnecessary catheterization and urinary tract instrument operations, and if necessary to retain catheterization, prophylactic use of antimicrobial agents should be considered. For women with recurrent infections related to sexual life, urination should be performed immediately after sexual intercourse, and 1 dose of SMZ-TMP should be taken. Pay more attention to the cleanliness of the vulva during pregnancy and menstruation.

　　1. Urinalysis

　　It is the simplest and most reliable detection method, and it is recommended to collect the first morning urine for testing. Any urine with more than 5 white blood cells per high-power field (>5 cells/Hp) is called purulent urine. More than 96% of symptomatic UTI patients can have purulent urine. Direct microscopic examination is very unreliable. The detection of urinary white blood cell excretion rate is relatively accurate, but it is too cumbersome. Currently, it is advocated to use the white blood cell lipase test, which shows a positive reaction when the white blood cell count per milliliter exceeds 10. Its sensitivity and specificity are 75% to 96% and 94% to 98%, respectively. In addition to purulent urine in acute urinary tract infections, white blood cell casts, bacteriuria, and sometimes microscopic or gross hematuria may be found. Especially in the case of Brucella, Nocardia, and Actinomycetes (including tuberculosis bacilli) infections,微量proteinuria may occasionally be seen. If there is a lot of proteinuria, it suggests involvement of the glomeruli.

　　2. Urinary Bacterial Examination

　　More than 95% of UTIs are caused by Gram-negative bacteria, in sexually active women, saprophytic Staphylococcus aureus and Enterococcus faecalis may occur, while some bacteria that寄生 in the urethral orifice, skin, and vagina, such as Staphylococcus epidermidis, Lactobacillus, anaerobic bacteria, and Bacillus cereus (diphtheria bacillus), rarely cause UTIs. In most cases, the presence of two or more bacteria in urine culture suggests sample contamination. In the past, it was believed that colony counts of more than 100,000 per milliliter of clean midstream urine had clinical significance, per milliliter

　　3. UTI Localization Examination

　　Including invasive and non-invasive examinations, bilateral ureteral catheterization has a high accuracy, but it must be performed through cystoscopy or percutaneous puncture of the renal pelvis to collect urine, so it is a traumatic examination and not commonly used. Cystoclysis is simple and easy to perform, commonly used in clinical practice, and has an accuracy of over 90%. The specific method is to inject 40ml of 2% neomycin solution into the bladder through the catheter to sterilize the bladder, then rinse with saline, and then collect the urine flowing into the bladder for culture. Urine samples are taken every 10 minutes, for a total of 3 times. If it is cystitis, the bacterial culture should be negative; if it is pyelonephritis, it will be positive, and the number of colonies will increase sequentially. Non-invasive examinations include urine concentration function, urine enzymes, and immune response detection. Acute and chronic pyelonephritis often accompany tubular concentration dysfunction, but this test is not sensitive enough to be used as a routine examination. Some patients with pyelonephritis may have elevated lactate dehydrogenase or N-acetyl-β-D-glucosaminidase in urine, but they lack specificity. To date, the urine enzymes that can help locate UTI are still under study. Recently, more applications have been detected in urine for antibody-coated bacteria. Bacteria from the kidneys have antibody coating, while bacteria from the bladder do not have antibody coating, so they can be used to distinguish between upper and lower urinary tract infections, but the accuracy is only 33%. Contamination from vaginal or rectal flora, large amounts of proteinuria, or infection invading the urethral epithelium outside the kidney (such as prostatitis, hemorrhagic cystitis, etc.) can all lead to false positives. 16% to 38% of adult acute pyelonephritis and most children can appear false negatives, so it is not routine. In addition, the determination of urine β2-microglobulin can also help distinguish between upper and lower urinary tract infections. Upper urinary tract infections are more likely to affect the reabsorption of small molecular proteins by the renal tubules, resulting in an increase in urine β2-microglobulin, while lower urinary tract infections do not increase urine β2-microglobulin. Some literature reports that serum C-reactive protein is significantly increased during pyelonephritis and can reflect the therapeutic effect, while it does not increase during acute cystitis. However, due to the increase in C-reactive protein in other infections, it affects the reliability of this test.

　　4. X-ray Examination

　　Due to the fact that acute urinary tract infection itself is prone to cause vesicoureteral reflux, intravenous or retrograde pyelography should be performed 4 to 8 weeks after the infection is eliminated. There is no routine recommendation for pyelography in acute pyelonephritis and uncomplicated recurrent UTI. For patients with chronic or refractory diseases, urinary tract plain film, intravenous pyelography, retrograde pyelography, and bladder ureteral reflux imaging during micturition can be performed as needed to check for obstruction, calculi, ureteral stenosis or compression, nephropexy, congenital malformations of the urinary system, and vesicoureteral reflux phenomena. In addition, it can also understand the morphology and function of the renal pelvis and calyces, thereby distinguishing from kidney tuberculosis, kidney tumors, etc. Renal angiography can show varying degrees of tortuosity of small blood vessels in chronic pyelonephritis. If necessary, renal CT scan or magnetic resonance imaging can be performed to rule out other kidney diseases.

　　5. Radionuclide renal scan

　　It can understand the function of the divided kidney, urinary tract obstruction, vesicoureteral reflux, and residual urine in the bladder. The renal scan characteristics of acute pyelonephritis are a peak shift after the peak, the secretion segment appears slower than normal by 0.5-1.0 minutes, and the excretion segment decreases slowly; the secretion segment of chronic pyelonephritis has a reduced slope, the peak becomes blunt or widened and shifted, the starting time of the excretion segment is delayed, and it presents in a parabolic shape, but the above changes have no obvious specificity.

　　6. Ultrasound examination

　　It is the most widely used and simplest method. It can screen for incomplete urinary tract development, congenital malformations, polycystic kidney disease, renal artery stenosis, uneven kidney size, kidney stones, severe renal pelvis积水, tumors, and prostatic diseases, etc.

　　Firstly, diet

　　Prescription 1

　　Composition: 15g adzuki beans or red beans, 15g Job's tears.

　　Preparation and usage: Cook adzuki beans or red beans with Job's tears into porridge, and add one spoon of rock sugar for consumption.

　　Indications: Urinary tract infection.

　　Prescription 2

　　Composition: 15g Dianthus chinensis, 60g Job's tears, rock sugar.

　　Preparation and usage: Boil Dianthus chinensis for juice, cook Job's tears into porridge for 2 bowls, mix the above ingredients with the medicine juice, and add one spoon of rock sugar. Take regularly.

　　Effects: Relieving heat, detoxifying, and diuretic.

　　Indications: Urinary tract infection.

　　Prescription 3

　　Composition: 6g light core grass, 4 bamboo leaves, 30g Job's tears, rock sugar.

　　Preparation and usage: Boil and squeeze the juice of light core grass or bamboo leaf, add Job's tears to cook porridge, and then add one spoon of rock sugar for consumption.

　　Effects: Diuretic and detoxifying.

　　Indications: Urinary tract infection.

　　Prescription 4

　　Composition: 15g螺 meat, 6g chopped green onions, Job's tears.

　　Preparation and usage: Add chopped green onions, wine, soy sauce, salt, and monosodium glutamate to the螺 meat, stir-fry until done, then add Job's tears and cook into porridge for consumption.

　　Indications: Urinary tract infection.

　　Prescription 5

　　Composition: 200g grass root, 200g rice.

　　Preparation and usage: Clean the fresh grass root, boil in an appropriate amount of water for half an hour, remove the dregs and take the juice, then cook with rice to make porridge. Eat for breakfast.

　　Indications: Urinary tract infection.

　　Prescription 6

　　Composition: 50g adzuki beans, 100g glutinous rice, 100g bamboo leaf vegetables.

　　Preparation and usage: Add 1000ml of water to the pot, bring to a boil with adzuki beans and glutinous rice, and cook until the beans and rice are blooming. Boil with bamboo leaf vegetables (cleaned and chopped). Eat regularly.

　　Indications: Urinary tract infection.

　　Prescription 7

　　Composition: 60-90g of plantain seed grass, 200g of pig small intestines.

　　Preparation and usage: Cut pig small intestines into small pieces, cook with 60-90g of fresh plantain seed grass (20-30g of dried product) and an appropriate amount of water. Add a little salt for seasoning. Drink the soup and eat the pig small intestines.

　　Indications: Urinary tract infection.

　　Prescription 8

　　Composition: 500g sugarcane, 500g fresh lotus root.

　　Preparation and usage: Fresh sugarcane is peeled, chopped, and juiced. Young lotus root is chopped and juiced. Mix the two juices evenly. Drink 3 times a day.

　　Indications: Urinary tract infection.

　　Secondly, what to eat for postpartum urinary tract infection:

　　1. Drinking an adequate amount of water, at least 3000cc per day, can be replaced by other liquids. Try to finish drinking it during the day to avoid frequent urination at night.

　　2. Increasing the acidity of urine can prevent recurrence. This can be achieved by consuming meat, eggs, cheese, plums, grains, prunes, and dried grapes, or by drinking cranberry juice, hawthorn juice, and also by supplementing with Vitamin C.

　　III. What not to eat for postpartum urinary tract infection:

　　1. Avoid spicy and刺激性 food.

　　2. Avoid cold and cold food.

　　3. Avoid spicy and刺激性 food.

　　I. Drug Treatment

　　1. Pyelonephritis:For acute pyelonephritis, SMZ-Co, twice a day, two tablets per time; norfloxacin (fluorofurazone, flumethazine), three times a day, 400mg per time, not for breastfeeding mothers; cefametin (cefalexin), four times a day, 1g per time; for severe cases, sensitive antibiotics should be chosen for intramuscular or intravenous administration according to the results of urine bacterial culture, such as penicillin, carbenicillin (ampicillin) for enterococcus and Proteus, carbenicillin (carbenicillin) or piperacillin (oxazepam penicillin) or third-generation cephalosporin drugs for patients infected with Pseudomonas aeruginosa and Escherichia coli; for patients with normal renal function, aminoglycoside antibiotics such as amikacin (butylpencillin) or tobramycin can also be chosen. If the pathogen is a fungus, ketoconazole or flucytosine should be chosen, and if the drug is ineffective after 48 hours of administration, the drug should be changed. The duration of treatment is generally 10-14 days, and routine urine examination and urine culture should be re-examined once a week after stopping the drug. The standard for cure is the disappearance of symptoms and signs, normal urine routine, and continuous negative urine culture for three times, and it is necessary to follow up for half a year without recurrence before it can be considered cured.

　　2. Cystitis:There is no special treatment, the same as during pregnancy. Generally, oral ampicillin (ampicillin) or nitrofurantoin can be taken.

　　II. Prognosis

　　If the recurrence of UTI occurs 3 times or more within one year, it is also called recurrent UTI, and long-term low-dose treatment can be considered. Generally, low-toxicity antibacterial drugs such as trimethoprim-sulfamethoxazole or nitrofurantoin, one tablet per night, can be taken for one year or longer, and about 60% of patients will have negative bacteriuria. If the urine culture remains positive after two courses of adequate antibacterial treatment, long-term low-dose treatment can be considered. Generally, cotrimoxazole or nitrofurantoin can be taken once a night, which can be taken for one year or longer, and about 60% of patients will have negative bacteriuria. Treatment of recurrent UTI in women.