Urinary Tract Infections PDF

10/19/23, 3:41 AM Realizeit for Student Infections of the Urinary Tract Urinary tract infections (UTIs) are caused by pathogenic microorganisms in the urinary tract (the normal urinary tract is sterile above the urethra). UTIs are generally classified by location as infections of the lower urinary...

10/19/23, 3:41 AM Realizeit for Student Infections of the Urinary Tract Urinary tract infections (UTIs) are caused by pathogenic microorganisms in the urinary tract (the normal urinary tract is sterile above the urethra). UTIs are generally classified by location as infections of the lower urinary tract, involving the bladder and structures below the bladder, or upper urinary tract, involving the kidneys and ureters. A UTI is the second most common infection in the body. UTIs account for nearly 25% of all infections and are commonly diagnosed in women visiting emergency departments in the United States. Approximately 8.1 million women are diagnosed with UTIs in the United States annually (Freeman, Martin, & Uithoven, 2017). In addition, UTIs are the cause of more than 100,000 hospital admissions annually (Freeman et al., 2017). Fifty percent of all hospital-acquired infections are UTIs, and in the majority of cases these are catheter-associated urinary tract infections (CAUTI) (Freeman et al., 2017). A CAUTI is a UTI associated with indwelling urinary catheters. The definition used for ongoing monitoring is a UTI that occurs while the patient had an indwelling urinary catheter in place for more than 2 calendar days on the day that the infection was detected. Lower Urinary Tract Infections The sterility of the bladder is maintained by several mechanisms, especially important since the urethra is considered a clean, not a sterile space. The physical barrier of the urethra assists in keeping bacteria away from the bladder, while urine flow helps to carry any bacteria away from the bladder. In addition, ureterovesical junction competence, various antibacterial enzymes and antibodies, and antiadherent effects mediated by the mucosal cells of the bladder all play a major part in protecting the sterility of the bladder. Abnormalities or dysfunctions of any of these mechanisms are contributing risk factors for lower UTIs. Lower UTIs include bacterial cystitis (inflammation of the urinary bladder), bacterial prostatitis (inflammation of the prostate gland), and bacterial urethritis (inflammation of the urethra). https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IcdpKuauTn1W0lrWmCsonBYnaQIwEDgwdbmVgOEy99af… 1/7 10/19/23, 3:41 AM Realizeit for Student Pathophysiology For infection to occur, bacteria must gain access to the bladder, attach to and colonize the epithelium of the urinary tract to avoid being washed out with voiding, evade host defense mechanisms, and initiate inflammation. Many UTIs result from fecal organisms ascending from the perineum to the urethra and the bladder and then adhering to the mucosal surfaces. Bacterial Invasion of the Urinary Tract By increasing the normal slow shedding of bladder epithelial cells (resulting in bacteria removal), the bladder can clear large numbers of bacteria. Glycosaminoglycan (GAG), a hydrophilic protein, normally exerts a nonadherent protective effect against various bacteria. The GAG molecule attracts water molecules, forming a water barrier that serves as a defensive layer https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IcdpKuauTn1W0lrWmCsonBYnaQIwEDgwdbmVgOEy99af… 2/7 10/19/23, 3:41 AM Realizeit for Student between the bladder and the urine. GAG may be impaired by certain agents (cyclamate, saccharin, aspartame, and tryptophan metabolites). The normal bacterial flora of the vagina and urethral area also interfere with adherence of Escherichia coli. Urinary immunoglobulin A (IgA) in the urethra may also provide a barrier to bacteria. Reflux An obstruction to free-flowing urine is a condition known as urethrovesical reflux, which is the reflux (backward flow) of urine from the urethra into the bladder (see Fig. 49-1). With coughing, sneezing, or straining, the bladder pressure increases, which may force urine from the bladder into the urethra. When the pressure returns to normal, the urine flows back into the bladder, bringing into the bladder bacteria from the anterior portions of the urethra. Urethrovesical reflux is also caused by dysfunction of the bladder neck or urethra. The urethrovesical angle and urethral closure pressure may be altered with menopause, increasing the incidence of infection in postmenopausal women. Ureterovesical or vesicoureteral reflux refers to the backward flow of urine from the bladder into one or both ureters (see Fig. 49-1). Normally, the ureterovesical junction prevents urine from traveling back into the ureter. The ureters tunnel into the bladder wall so that the bladder musculature compresses a small portion of the ureter during normal voiding. When the ureterovesical valve is impaired by congenital causes or ureteral abnormalities, the bacteria may reach the kidneys and eventually destroy them. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IcdpKuauTn1W0lrWmCsonBYnaQIwEDgwdbmVgOEy99af… 3/7 10/19/23, 3:41 AM Realizeit for Student Uropathogenic Bacteria Bacteriuria is the term used to describe the presence of bacteria in the urine. Because urine samples (especially in women) can be easily contaminated by the bacteria normally present in the urethral area, a clean-catch midstream urine specimen is the measure used to establish bacteriuria. In men, contamination of the collected urine sample occurs less frequently. Routes of Infection Bacteria enter the urinary tract in three ways: by the transurethral route (ascending infection), through the bloodstream (hematogenous spread), or by means of a fistula from the intestine (direct extension). The most common route of infection is transurethral, in which bacteria (often from fecal contamination) colonize the periurethral area and subsequently enter the bladder by means of the urethra (Freeman et al., 2017; Norris, 2019). In women, the short urethra offers little resistance to the movement of uropathogenic bacteria. Penile-vaginal intercourse forces the bacteria from the urethra into the bladder. This accounts for the increased incidence of UTIs in women who engage in penile-vaginal intercourse. Bacteria may also enter the urinary tract by means of the blood from a distant site of infection or through direct extension by way of a fistula from the intestinal tract. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IcdpKuauTn1W0lrWmCsonBYnaQIwEDgwdbmVgOEy99af… 4/7 10/19/23, 3:41 AM Realizeit for Student Clinical Manifestations Signs and symptoms of UTI depend on whether the infection involves the lower (bladder) or upper (kidney) urinary tract and whether the infection is acute or chronic. Signs and symptoms of an uncomplicated lower UTI include burning on urination, urinary frequency (voiding more than every 3 hours), urgency, nocturia (awakening at night to urinate), incontinence, and suprapubic or pelvic pain. Hematuria and back pain may also be present (Martin, Wingo, & Holland, 2019). In older adults, these symptoms are less common (see Gerontologic Considerations section). In patients with complicated UTIs, manifestations can range from asymptomatic bacteriuria to gram-negative sepsis with shock. Complicated UTIs often are caused by a broader spectrum of organisms, have a lower response rate to treatment, and tend to recur. Many patients with CAUTIs are asymptomatic; however, any patient with a catheter who suddenly develops signs and symptoms of septic shock should be evaluated for urosepsis (the spread of infection from the urinary tract to the bloodstream that results in a systemic infection). Gerontologic Considerations The incidence of bacteriuria in older adults differs from that in younger adults. Bacteriuria increases with age and disability, and women are affected more frequently than men. UTI is the most common infection of older adults and increases in prevalence with age. UTIs occur more frequently in women than in men at younger ages but the gap between the sexes narrows in later life, which is due to reduced penile-vaginal intercourse in women and a higher incidence of bladder outlet obstruction secondary to benign prostatic hyperplasia in men (Eliopoulos, 2018). In older adults, structural abnormalities secondary to decreased bladder tone, neurogenic bladder (dysfunctional bladder) secondary to stroke, or autonomic neuropathy of diabetes may prevent complete emptying of the bladder and increase the risk of UTI (Eliopoulos, 2018). When indwelling catheters are used, the risk of CAUTI increases dramatically. Older women often have incomplete emptying of the bladder and urinary stasis. In the absence of estrogen, postmenopausal women are susceptible to colonization and increased adherence of bacteria to the vagina and urethra. Oral or topical estrogen has been used to restore the glycogen content of vaginal epithelial cells and an acidic pH for some postmenopausal women with recurrent cystitis. The antibacterial activity of prostatic secretions that protect men from bacterial colonization of the urethra and bladder decreases with aging. The use of catheterization or cystoscopy in evaluation or treatment for prostatic hyperplasia or carcinoma, strictures of the urethra, and neuropathic bladder may contribute to the higher incidence of UTIs in men. The incidence of https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IcdpKuauTn1W0lrWmCsonBYnaQIwEDgwdbmVgOEy99af… 5/7 10/19/23, 3:41 AM Realizeit for Student bacteriuria also increases in men with confusion, dementia, or bowel or bladder incontinence. The most common cause of recurrent UTIs in older males is chronic bacterial prostatitis. Resection of the prostate gland may help reduce its incidence. Chart 49-2 lists other factors that may contribute to UTI in older patients. Diligent hand hygiene, careful perineal care, and frequent toileting may decrease the incidence of UTIs. The organisms responsible for UTIs in older adults residing in institutions may differ from those found in patients residing in the community; this is thought to result in part from the frequent use of antibiotic agents by patients in long-term care facilities. Escherichia coli is the most common organism seen in older patients in the community or hospital. However, patients with indwelling catheters are more likely to be infected with organisms such as Proteus, Klebsiella, Pseudomonas, or Staphylococcus. Patients who have been previously treated with antibiotics may be infected with Enterococcus species. Frequent reinfections are common in older adults. Early symptoms of UTI in postmenopausal women and older adults include malaise, nocturia, urinary incontinence, or a complaint of foul-smelling urine. Additional early symptoms include burning, urgency, and fever (Eliopoulos, 2018; Freeman et al., 2017). Some patients develop incontinence and delirium with the onset of a UTI. Antibiotics are prescribed when bacteriuria is present (Eliopoulos, 2018). Treatment regimens are generally the same as those for younger adults, although age-related changes in the intestinal absorption of medications and decreased kidney function and hepatic flow may necessitate alterations in the antimicrobial regimen. Kidney function must be monitored, and medication dosages should be altered accordingly. The nurse carefully monitors fluid intake and output. Increasing fluid intake is advisable, provided that the patient’s cardiac status does not contraindicate this action (Eliopoulos, 2018). https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IcdpKuauTn1W0lrWmCsonBYnaQIwEDgwdbmVgOEy99af… 6/7 10/19/23, 3:41 AM Realizeit for Student Example Video: YouTube: Urinary Tract Infection Nursing NCLEX | UTI Symptoms Treatment Cystitis, Pyelone https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IcdpKuauTn1W0lrWmCsonBYnaQIwEDgwdbmVgOEy99af… 7/7