Urinary tract infection in the elderly

　　How is urinary tract infection in the elderly caused? Briefly described as follows:

　　1. Causes of onset

　　The main pathogenic strains of urinary tract infection (UTI) in the elderly are Escherichia coli and Proteus, followed by Pseudomonas aeruginosa, Proteus, Klebsiella, Alcaligenes, and other Gram-negative bacteria. In recent years, it has been noted that urinary tract infections in the elderly caused by Gram-positive cocci (such as Staphylococcus, Enterococcus, etc.) are also common. In the elderly with structural or functional abnormalities of the urinary system, fungal infections (mainly Candida albicans) or L-type bacteria are significantly increased. Elderly patients with weakened physical condition or long-term bed rest can also suffer from severe UTI caused by various non-urinary tract pathogenic bacteria or opportunistic pathogens. In addition, some cases of acute urethritis syndrome in elderly females are caused by Chlamydia.

　　The exact mechanism of urinary tract infection (UTI) in the elderly is not yet fully understood. The following factors are known to be possibly related:

　　1. The adhesion sensitivity of the urinary tract epithelial cells in the elderly to bacteria has increased. This phenomenon has been observed in elderly males and females by different scholars, and it is most obvious in females. The cause is not yet clear, and some people speculate that it may be related to changes in estrogen levels. The stimulation of estrogen may increase the density of bacterial receptors on the cell surface and increase the activity of cell adhesion.

　　2. The factors causing urinary tract obstruction and poor urine flow in the elderly have significantly increased, making it easier for bacteria to survive and reproduce. The elderly often suffer from incomplete or complete urinary tract obstruction due to benign prostatic hyperplasia, bladder neck obstruction, urinary tract stones, tumors, and other reasons. At the same time, the probability of neurogenic bladder or flaccid bladder also increases significantly. These factors can lead to poor urine flow, increased residual urine in the bladder, and reduced local antibacterial ability of urothelial cells, making it easier to develop infections.

　　3. Due to aging, the immune response ability of the elderly is reduced both locally and globally. The humoral immune and cellular immune functions of the elderly are significantly weakened, leading to a decrease in their ability to respond to infections and other stress factors. At the same time, the kidneys and bladder membranes of the elderly are in a relatively ischemic state, and conditions such as relaxed pelvic muscles and habitual constipation can further exacerbate the poor blood circulation of local mucous membranes. The reduction in prostatic secretion in elderly males also contributes to the decrease in local resistance. In addition, the degenerative changes of the elderly kidney are also one of the reasons for the decline in the defense mechanism of the urinary tract mucosa.

　　4. Other physiological thirst sensation decline in the elderly, reduced water intake, and changes in the concentrating and diluting functions of renal tubules all have a certain impact on the susceptibility of UTI. At the same time, the elderly often have systemic diseases such as hypertension and diabetes, the incidence of malnutrition and long-term bed rest is increased, and they are often滥用 analgesics, non-steroidal anti-inflammatory drugs, and other drugs due to illness, so they are prone to UTI, and even lead to chronic interstitial nephritis or chronic pyelonephritis.

　　Secondly, pathogenesis

　　The decline in immune function in the elderly, insufficient resistance to infection, plays an important role in the pathogenesis of urinary tract infections. Moreover, the elderly often have systemic diseases such as hypertension, atherosclerosis of renal arteries and renal arterioles, diabetes, and so on. In addition, the function of renal tubules and bladder decreases with age, which also affects urination and defecation. These are all contributing factors to the high incidence, recurrent occurrence, and difficulty in curing urinary tract infections in the elderly. The decline in renal tubular function in the elderly is manifested by a decrease in the function of water and sodium transport, as well as a decrease in urine concentration ability. The increased content of urinary β2-MG detected by radioimmunoassay can sensitively reflect the decline in renal tubular function in the elderly after excluding other diseases. The urinary osmolality of healthy elderly people is 500-700 mmol/L, and the ratio of urine to blood osmolality and the pure water clearance rate (CH2O) are lower than those of middle-aged and young adults. In addition, the elderly have a decline in the metabolism of drugs excreted by the kidneys, which is prone to renal tubular drug intoxication, chemical injury, and is more likely to attract upper urinary tract infections. The lower urinary tract shows functional abnormalities with age, manifesting as irregular urination and an increase in the number of times to urinate at night and during the day. Brocklehurst et al. found that 70% of elderly men and 60% of elderly women have an increased phenomenon of nocturia, with men often having urgency and women often having difficulty urinating, incontinence, and stress urinary incontinence. The speed of urination in asymptomatic elderly people also gradually slows down. The maximum urination speed of elderly people over 65 is >13ml/s, which is within the normal range. The physiological basis that affects the speed of urination in the elderly has not been fully understood, but it is certainly the result of the interaction of multiple factors. In addition, local structural changes such as frequent elderly renal cysts, renal calculi, urinary tract mechanical obstruction, vesicoureteral reflux, decreased cardiac output due to cardiovascular disease, and neurogenic bladder due to cerebrovascular disease all affect the speed and volume of urination in the lower urinary tract and are prone to urinary tract infections.

　　Senior urinary tract infections (UTI) are prone to complications such as sepsis, bacteremia, and septic shock, which are the main causes of sepsis in the elderly (accounting for about 1/3), and should be a matter of alert for clinical physicians. Secondly, elderly urinary tract infections, especially in female patients, can cause vaginal infections due to urinary pollution of the vagina, and the infection can further ascend and merge with cervicitis and endometritis. However, for asymptomatic urinary tract infections, the presence of leukocytes in simple urinalysis is generally without complications in the elderly and does not require treatment.

　　The clinical manifestations of elderly urinary tract infections (UTI) are atypical. Most elderly patients with UTI present with extrarenal non-specific symptoms, such as fever, discomfort in the lower abdomen, lumbosacral pain, decreased appetite, etc.; some elderly patients may only manifest fatigue, dizziness, or confusion of consciousness. Therefore, it is easy to misdiagnose or miss the diagnosis of elderly UTI based solely on clinical manifestations. In addition, most elderly UTI is chronic and refractory, with a high recurrence rate and re-infection rate.

　　The prevention of this disease mainly involves attention to hygiene habits and lifestyle. Good hygiene habits can reduce the opportunity for pathogen infection. A healthy lifestyle can enhance the body's resistance and avoid pathogen infection. Other preventive measures such as drinking plenty of water and tea can increase urine secretion. Due to the increased urine volume, the flushing effect on the bladder and ureters is strengthened, which can also prevent bacterial infection.

　　What examinations should elderly patients with urinary system infections undergo? A brief description is as follows:

　　1, Urinalysis

　　Increased excretion of urinary leukocytes indicates urinary tract inflammation and is also of great significance in diagnosis. The correlation between leukocyte urine and urinary tract infections has long been recognized. The incidence of pyuria in asymptomatic bacteriuria is about 37%, and leukocyte excretion >10/mm3 is considered abnormal.

　　2, Bacterial culture

　　The most common pathogenic bacteria for urinary tract infections are Gram-negative bacilli, among which Escherichia coli accounts for the first place (90%), followed by Pseudomonas aeruginosa and Proteus mirabilis. Interestingly, these bacteria are also common in children, but rare in adults. Some propose that prostatic secretions may shorten the survival period of these bacteria, which can explain the higher incidence of urinary tract infections in elderly males after prostatectomy.

　　3, Imaging technology

　　Imaging technology (including excretory urography and gallium scan) is helpful for identifying the location of elderly urinary system infections.

　　A brief description of the dietary therapy for elderly patients with urinary system infections is as follows:

　　1, Plantain seed grass 100 grams, bamboo leaf heart and raw licorice root each 10 grams, with appropriate amount of sugar, decocted into a soup and taken as tea, one dose per day. This recipe has antibacterial and antiviral effects and has good efficacy for urinary system infections and viral hepatitis.

　　2, Fresh mung bean sprouts 500 grams, juiced with appropriate amount of sugar. Taken frequently as tea, without any restrictions on quantity. This recipe is effective for urinary tract infections, red and hot urine, frequent urination, and other symptoms.

　　3, Fresh bamboo leaves and white grass root each 10 grams, placed in a thermal cup, infused with boiling water, covered for 30 minutes, and taken as tea frequently. This recipe is suitable for urinary tract infections and those with red blood cells in the urine.

　　4, Raw Astragalus membranaceus, white茅根30 grams, Cistanche deserticola 20 grams, watermelon rind 60 grams, decocted with appropriate amount of sugar, taken 2 to 3 times a day. This recipe tonifies the Qi and benefits the kidney, promotes diuresis and reduces swelling, and has a special effect on urinary tract infections.

　　5, Fresh sugarcane 500 grams, peeled and chopped, then squeezed for juice; tender lotus root 500 grams, with the joints removed and chopped, then the juice is mixed with the sugarcane juice, and taken 3 times a day. This remedy can treat symptoms such as red and hot urine.

　　6. Fresh plantain grass 60-90 grams (dried 20-30 grams), pork small intestines 200 grams, a little salt. Cut the pork small intestines into small pieces, add an appropriate amount of water and cook with plantain grass, season with salt, drink the soup and eat the pork small intestines, twice a day. This recipe is effective for cystitis and urethritis.

　　7. Talc 20-30 grams, huai mai 10 grams, sticky rice 50-100 grams. Wrap the talc with cloth and decoct it with huai mai in a pot, remove the dregs, and cook the sticky rice into a thin porridge, taken twice a day, for 3-5 days as a course of treatment. It is suitable for dysuria, frequent urination, urgency, dripping, and burning pain caused by acute cystitis.

　　The following is a brief description of the treatment methods for elderly urinary system infections:

　　1. Treatment

　　The first attention in the treatment of elderly UTI should be paid to the treatment of the underlying disease, removal of obstruction factors, and encouragement of patients to drink more water. Adequate hydration can dilute and flush the local bacteria, and can also reduce the hypertonic state of the renal medulla. For elderly female urethritis patients, it can be tried to use a small amount of estrogen locally, which may be beneficial for restoring the physiological state of the lower urinary tract.

　　It is generally believed that all patients with first-time detection of bacterialuria should be given a single course of antibiotic treatment. Most studies have found that due to the extremely high recurrence rate and reinfection rate of UTI in the elderly, it is unnecessary and cannot reduce the recurrence rate or mortality rate to maintain long-term antibiotic use for asymptomatic bacteriuria. Some people propose that only when there is early bladder infection, progressive renal function damage, and symptoms of upper urinary tract infection, more active treatment should be given to elderly patients with UTI. During the treatment process, the medication should be adjusted in real time according to urine culture and drug sensitivity test. When elderly patients with UTI are difficult to cure, attention should be paid to the existence of drug-resistant strains or special pathogens.

　　It is generally believed that long-term bacteriuria has a definite effect on renal function, but there is no definite opinion on its relationship with mortality and uremia.

　　2. Prognosis

　　There is no completely consistent conclusion about the impact of UTI on prognosis. Some believe that the mortality rate of asymptomatic bacteriuria does not change significantly, but when Dontas observed the 10-year survival status of 342 elderly patients, it was found that the average life span of 76 patients with urinary tract infection at the beginning was significantly lower than that of non-infected patients.