A urinary tract infection (UTI) is a bacterial invasion of the urinary tract. They are among the commonest bacterial infections managed in general practice, and are the reason for 1–3% of all GP consultations (National Institute for Health and Care Excellence (NICE), 2015).
The urinary tract is constantly exposed to bacteria from the exterior environment, particularly because of the anatomical placement of the urethra in the vicinity of the rectum in females (Okragla et al, 2014). In the USA, for example, a UTI is a common medical condition that accounts for 7 to 8 million clinic visits by women per year (Robinson et al, 2015). Recent studies have shown that women are more frequently affected with a UTI than men, often requiring antibiotic treatment (Babar et al, 2018).
A UTI is a debilitating condition in severe cases and can produce the onset of painful urination (dysuria), urinary frequency, the inability to start urinating (hesitancy) and the sensation of the sudden need to urinate (urgency) (Bono and Reygaert, 2018).
Bladder physiology and infection
The lower urinary tract consists of the ureters, the bladder, the trigone and the urethra (Watson, 2011). The bladder has three distinct layers (Patel and Chapple, 2008):
Mysorekar and Hultgren (2006) reported that an infection of the lower urinary tract occurs when bacteria invade the urethra, migrate to the urothelium and colonise the cells of the epithelium of the bladder. When the superficial bladder cells have been invaded, the uropathogens rapidly begin to replicate inside the bladder cells, forming intracellular communities, also known as intracellular colonisation. Intracellular pathogens such as Escherichia coli hijack bladder cells that line the urothelium, allowing pathogens to reach an appropriate intracellular position for their survival and replication (Panek et al, 2014).
The process of intracellular colonisation has been related to the development of urinary biofilms, which is the process in which infected bladder cells form a protective barrier, hindering the suppression of infected cell multiplication and promoting the progression of the UTI (Flores-Mireles et al, 2015). The multiplication of biofilms in the bladder cells hinders bladder function, triggering lower urinary tract symptoms (LUTS) such as urinary hesitancy, reduced urinary stream, bladder pain and incomplete bladder emptying, also known as urinary retention (Rosen and Klumpp, 2014).
Symptoms and assessment
In most cases when patients report LUTS, this is indicative of a sudden or worsening onset of a UTI, also known as an acute flare. It may present as storage, voiding and incontinence symptoms (Haylen et al, 2010).
Using a validated tool to make an assessment of symptoms offers a systematic method for measuring and assessing the presence of urinary frequency, urgency, urinary incontinence, voiding symptoms and bladder pain (Al-Buheissi et al, 2008), as well as the impact of these on a patient's quality of life. Available tools include the Female Lower Urinary Tract Symptoms (FLUTS) questionnaire (Jackson et al, 1996) and the quality-of-life questionnaire for urinary incontinence (I-QOL) (Wagner et al, 1996).
It is good practice for nurses to use a validated assessment tool and, depending on the clinical setting, such as hospital, community or outpatient department, local assessment tools may have been developed based on the concept of the FLUTS and I-QOL questionnaires.
Urine samples and diagnostic testing
A UTI is often diagnosed by examining a urine sample. In nursing practice, there are two main methods for obtaining a specimen (Dougherty et al, 2015):
Collection-method selection depends on the patient's clinical case, but an MSU is the more common method for testing.
A dipstick urinalysis is generally used in clinical practice, because it is a rapid and inexpensive diagnostic test. It is performed in conjunction with, or in place of, a urine culture (Huysal et al, 2013). A dipstick urinalysis measures the markers of pyuria and bacteriuria, the two diagnostic factors often associated with a UTI (Turner et al, 2014).
When interpreting a dipstick urinalysis, pyuria is the measurement of urinary leukocytes and bacteriuria is the presence of nitrites (Pappas, 1991). Not all dipstick tests are sensitive enough to detect the presence of both leukocytes and nitrites, but identifying either one of these signs increases the positive predictive value of the urinalysis (Raza-Khan et al, 2006).
Although it is a standard method for routinely screening for the presence of infection, the usefulness of the dipstick has been questioned owing to its lack of sensitivity in detecting the presence of a UTI in comparison with urine microscopy (Khasriya et al, 2010).
Urine microscopy has been used to identify urinary leukocytes since the early 1890s. Dukes (1928) introduced another method of assessing urine using a counting chamber to enumerate the white cells in a fresh unspun specimen. Later studies investigated the use of urinary microscopy for identifying bacteriuria as an alternative to relying on urine cultures (Hällström et al, 1975; Vickers et al, 1991; Hiraoka et al, 1993).
Urine microscopy is also used to detect the presence of haematuria (Yeoh et al, 2013) and uroepithelial cells, which originate from the bladder wall and indicate inflammation in the bladder and exfoliation of infected bladder cells into the urinary stream (Horsley et al, 2013; Khasriya et al, 2013).
More recent studies advocate the use of light microscopy as a standard screening practice for detecting pyuria and bacteriuria in males and females (Sorrentino et al, 2015; Gill et al, 2018). Nurses in some clinical settings undertake urinary microscopy after adequate training.
Urine cultures have been recommended as the gold standard for diagnosing the pathogens that are responsible for a UTI (Davies and Lewis, 2004) and, although nurses are not trained to perform urine cultures, the ability to promptly send a urine specimen for microbiological testing, culture and antibiotic sensitivity is an important task.
Bacterial infections are recognised as the most common aetiological cause of a UTI, and account for 75–90% of diagnosed cases in both outpatient and inpatient settings (Kashef et al, 2010). Research has shown that a bacterial infection of the bladder can disrupt the function of the urothelium, the bladder's protective lining, triggering an inflammatory response that causes the parasitised transitional cells to migrate to the surface of the bladder, exfoliate and pass out as part of the urinary stream (Anderson et al, 2003; Reigstad et al, 2007; Khasriya et al, 2013).
These exfoliated urothelial cells, detected on microscopy, are regarded as important diagnostic markers of infection. Some methods of analysis would interpret these cells as a contaminants (Collier et al, 2014), but novel methods of cell identification have shown these cells to originate from the bladder and are a reflection of the infection (Horsley et al, 2013).
Nursing management of a UTI
Nurses have the ability to assess and identify the presence of UTI with appropriate training. When a UTI has been identified, nurses should refer the patient to a doctor or a nurse prescriber who will then proceed with treatment options.
Acute and chronic UTIs are often managed by prescribing antibiotics. Methenamine hippurate is an effective bladder antiseptic for preventing the progression of a UTI (Lee et al, 2012). Treatment cessation is usually permitted when there is a reduction in LUTS and a visible reduction in urinary pyuria (Swamy et al, 2018).
It is important that nurses encourage patients to report the initial onset of bladder symptoms, as early intervention often helps to prevent the progression of the infection. The fundamental role of the nurse when managing a UTI is to conduct a comprehensive symptom assessment. An assessment using validated questionnaires is an integral part of urology practice and is a structured method to record the duration of symptoms, triggers and exacerbating factors (Betschart et al, 2018).
Understanding the symptom characteristics will support nurses when educating the patient on recognising these and the importance of early reporting of any symptoms. Examining a specimen of urine will determine whether an infection is present and promptly reporting the findings will hasten the facilitation of the treatment process (Nik-Ahd et al, 2018).
Conclusion
UTIs are a common debilitating condition, with women being more often affected than men. Understanding the anatomy of the urinary system provides a clearer perspective of how bacteria invades the bladder, causing the infection.
The assessment and identification of the infection is crucial and nurses have a fundamental role when assessing symptoms, examining a specimen of urine and promptly reporting the findings.