Infection control. focus

Transcription

1 Infection control focus By reading this article and writing a practice profile, you can gain ten continuing education points (CEPs). You have up to a year to send in your practice profile. Guidelines on how to write and submit a profile are featured at the end of this article. Diagnosis and management of urinary tract infection in children NS143 Poole C (2002) Diagnosis and management of urinary tract infection in children. Nursing Standard. 16, 38, Date of acceptance: May Aims and intended learning outcomes The aim of this article is to unravel the complexities linked to the diagnosis, management and investigation of urinary tract infection (UTI) in children. It also aims to explore the research base associated with the collection of urine samples, as this is the fundamental nursing skill connected with the diagnosis of UTI. After reading this article you should be able to: Debate the advantages and disadvantages of the different methods of urine collection from children. Discuss the usefulness of urine-dip testing and urine microscopy as diagnostic investigations. Profile the radiological and non-radiological techniques that might be used to identify high-risk renal tracts. Give an overview of the principles of prophylactic antibiotic use. Appreciate the importance of early diagnosis of UTI in children. Introduction UTI causes significant illness, particularly in the first two years of life, and has the potential to cause permanent renal damage for those children in whom a renal tract abnormality is subsequently identified (Benador et al 1997, Risdon 1993, Sreenarasimhaiah and Hellerstein 1998), such as vesico-ureteric reflux, posterior urethral valves, neuropathic bladder or pelvi-ureteric junction obstruction. Diagnosis of UTI in children is dependent on the collection of an uncontaminated, freshly voided urine sample. While this seems a simple concept, in reality it poses a significant dilemma both in the hospital and community setting and is the key to the future management and follow-up of these patients. This difficulty in obtaining a clean, uncontaminated urine sample from children is reflected in the ongoing literature searching for a reliable method (Al-Orifi 2000, Beeram and Dhanireddy 1997, Buys et al 1994, Farrell 2002, Feasey 1999, Rees et al 1996, Vernon et al 1994). Prevention of long-term renal damage remains a priority. TIME OUT 1 Before reading on try to answer the following questions. This will allow you to reflect on your current level of knowledge of the topic. How many children experience UTI? What percentage of children will have an associated renal tract abnormality? How many methods of urine collection are employed in the paediatric setting? Which method of urine collection has the highest risk of contamination? Which chemical reagent pads are primarily used to aid the diagnosis of UTI? Which radiological investigations should children undergo following their first confirmed UTI? Why are prophylactic antibiotics used for some children and not for others? Diagnosis and management of urinary tract infection in children Multiple-choice questions and submission instructions 54 Practice profile assessment guide 55 A reader s practice profile 25 In brief Author Catherine Poole RGN, RSCN, MSc, PgDip (Education), is Lecturer Practitioner, University of Central England, Edgbaston, Birmingham. Summary Urinary tract infection (UTI) causes significant illness, particularly in the first two years of life, and has the potential to cause permanent renal damage. Diagnosis of UTI in children is dependent on the collection of an uncontaminated freshly voided urine sample, which is key to the future management and follow-up of these patients. Prevention of possible long-term renal damage remains a priority. Key words Children Paediatric nursing Urinary system Disorders These key words are based on subject headings from the British Nursing Index. This article has been subject to double-blind review. Online archive For related articles visit our online archive at: and search using the key words above.

2 C O N T I N U I N G PROFESSIONAL DEVELOPMENT It is estimated that UTI is one of the most common bacterial infections of childhood after ear and throat infection (Bonadio 1990, Marild et al 1989). According to Lee and Verrier Jones (1991), UTI in childhood accounts for 5 per cent of children admitted to hospital with febrile convulsion and for many primary care consultations. Conflicting evidence surrounds the total percentage of children who experience UTI. For example, Bergstrom (1972) estimated that at least 1 per cent of boys and 3 per cent of girls will experience their first UTI under 24 months of age, however, Marild et al (1989) were of the opinion that the incidence was twice as high. There is some evidence to suggest that this discrepancy is, in part, related to the difficulties encountered in the reliable diagnosis of UTI, particularly in the non-toilet-trained age group. It has been suggested (Verrier Jones and Newall 2000) that many UTIs in young children remain undetected for some time. This might lead to avoidable morbidity and predispose the child to renal scarring, also referred to as reflux nephropathy or chronic pyelonephritis. Boys are affected more often than girls during the first month after birth, when incidence is highest. However, this changes over time. By six months of age, UTI is more common in females and interestingly the re-infection rate is also more common in females than males. According to James Ellison et al (1994), several host factors are age related and might explain the relationship between incidence, age and sex. The Swedish promote awareness among parents and health professionals of the issues surrounding the diagnosis and management of UTI in young patients. In Sweden the average age for first UTI is recorded as less than four months in males and less than seven months in females. In contrast the UK records an average age of referral to be 4.8 years (McKerrow et al 1984). TIME OUT 2 The early detection of UTIs in other countries suggests that it is possible to prevent problems much earlier than currently happens in the UK. With reference to the following headings, discuss with your colleagues what might need to be done to improve our diagnosis rates: Education of parents. Education of healthcare professionals. Routine monitoring of children in clinics. Understanding the longer-term significance of untreated UTIs. Diagnostic services. The focus on early diagnosis has had a positive effect on the number of children developing renal scarring because of reflux nephropathy: 0-5 per cent in Sweden compared to per cent of children with proven UTI in the UK. Pathogenesis of UTI With the exception of the distal part of the urethra, the urinary tract is normally sterile. Therefore, it seems strange that UTI is so common in the paediatric population. Some patients appear to have a tendency for repeated UTIs and it is thought that their defence against bacterial entry, persistence and growth in the urinary tract is in some way deficient (Hansson and Jodal 1996). Escherichia coli cause between 80 and 90 per cent of the first UTIs in children. Other common causative organisms include Klebsiella, Proteus and Staphylococcus saprophyticus (Hansson and Jodal 1996). In children who have an underlying urinary tract malformation or dysfunction, it is common for less virulent bacterial species such as enterococci, Pseudomonas, Staphylococcus aureus or Staphylococcus epidermidis, Haemophilus influenzae and streptococcus (Group B) to cause UTI. Viral pathogens appear to be less significant with the exception of adenoviruses, which can cause haemorrhagic cystitis (Miller 1996). Fungal UTIs are rare, but should be considered in immunocompromised patients or those receiving long-term antimicrobial therapy. Bacteria that cause UTIs usually originate in the bowel; however, boys also have a tendency to harbour organisms under the prepuce. Bacteria migrate up the urethra and quickly colonise the bladder. The periurethral area is normally colonised by aerobic and anaerobic bacteria, which form part of the normal defence barrier against pathogens. If for some reason this normal defence barrier is altered (following a course of antibiotics, for example) this increases the risk of pathogens ascending the urethra. The short female urethra and close proximity to the anus provide a suitable invitation to invading organisms. Once in the bladder, further ascent of the bacteria can be facilitated if the child has vesicoureteric reflux (VUR). E coli can invade the upper urinary tract in the absence of VUR. This is thought to be linked to the ability of some E coli to stick to uroepithelial cells (Hansson and Jodal 1996). Urine is an ideal medium for bacterial growth. The bladder has at least two mechanisms that defend against bacterial invasion regular elimination of bacteria through bladder micturition and bacterial destruction by epithelial cells. Therefore, incomplete bladder emptying or urinary stasis has the potential to increase the risk of UTI. According

3 to Hansson and Jodal (1996), the role of specific immunity for resistance against UTI in humans remains an issue of debate. It has been suggested that the natural resistance to infection depends more on the inflammatory reaction than on a specific immune response. Diagnosis of UTI This is dependent on four key procedures: urine collection, urine analysis, urine microscopy and urine culture. Urine in the normal bladder is sterile, however, urine can become contaminated during micturition and collection in an appropriate sampling container. Contamination has the potential to lead to a false-positive diagnosis of UTI and subsequent inappropriate investigation and treatment. Conversely, failure to accurately identify the child with UTI might have an associated risk of renal scarring (Benador et al 1997). The crux of diagnosis, therefore, hinges on the collection of a clean uncontaminated urine sample that can be processed by the microbiology department. Confirmation of a positive culture can then be a reliable diagnostic tool. Urine collection Healthcare professionals faced with a child who is unwell have for many years searched for a reliable urine collection method. Urine sampling needs to be timely, easy to carry out in hospital and community settings, cost-effective, and most importantly have the ability to reduce the risk of bacterial contamination rates. Box 1 lists the methods of urine collection currently available. Midstream specimens These remain the method of choice because only social cleanliness and dryness are required. However, in practice this method is only of use in a co-operative toilet-trained child. The significance of a midstream collection is grounded in the theory that the first urine, which contains most of the contaminating bacteria from the periurethral area, is omitted, thereby reducing the contamination rate. Clean-catch Macfarlane et al (1999) reported only a 12 per cent contamination rate using the cleancatch technique. Ramage et al (1999) also reported on the efficiency of the clean-catch technique. However, other authors report this method to be time consuming and technically difficult (Feasey 1999, Lewis 1998, Vernon 1995). This method also requires cleanliness and dryness of the urethral and perineal area. As little as 1ml of urine caught during micturition is adequate for microbiological purposes. In infants, micturition occurs as a reflex stimulated by bladder fullness. This reflex is often provoked during exposure to cold, and the astute parent or nurse, well prepared with a sterile container, is often able to collect a cleancatch urine sample when the infant is being undressed (Poole 1999). Adhesive bag This method of urine collection is fraught with complications (Al-Orifi et al 2000, Waddington and Watson 1997, Vernon et al 1994). The contamination rates far outweigh any other validated method and are reported to be as high as 45 per cent (Al-Orifi et al 2000). Other criticisms of this method include difficulty in application, leakage prompting reapplication, discomfort for the child and cost (up to 1 each). Despite this evidence, adhesive urine bags remain available from NHS Supplies. Suprapubic aspiration This remains the gold standard for urine collection from non-toilet-trained infants (Buys et al 1994, Miller 1996). Catheter sample This method, while efficient, is seldom used perhaps because of the risk of introducing infection into the bladder and concern about psychological effects on children above one year of age (Hoberman et al 1994). Disposable nappies Disposable nappies have been assessed for their suitability as a method of urine collection (Ahmad et al 1991, Beeram and Dhanireddy 1990). Both studies concluded that this method could be used, however there was evidence that the nappy fibres filtered out some of the urinary sediment and that caution should be adopted if this method was being used for the diagnosis of UTI. Some brands of nappies contain bleaching agents, which are E. coli inhibitors and place further caution on their use. Since the addition of gel beads during the manufacturing process of nappies, the increased absorptive properties have rendered this technique almost impossible. Urine collection pad Since their launch in 1994 (Vernon et al 1994) this method of urine collection has been debated. Ease of use, low cost (59p for a pack containing syringe, bottle and two pads) and availability from NHS Supplies have increased the use of urine collection pads (Feasey 1999, Lewis 1998, Vernon 1995). However, caution has been raised with regard to the filtering effect of the pad fibres and the high contamination rates of up to 68 per cent (Farrell 2002, Macfarlane et al 1999). Washed-up potties In a quest to develop a urine collection method that had relevance in hospital and community settings, Rees et al (1996) examined the efficacy of removing bacteria from the surface of children's potties using what they describe as the 'washed-up' method. They advocate that this method is reliable if the potty is first cleaned in hot water with detergent, thus removing the bacteria rather than attempting to sterilise it. This method would benefit from further evaluation. Box 1. Urine collection methods Midstream specimen Clean-catch Adhesive bag Suprapubic aspiration Catheter sample Disposable nappies Urine collection pad Washed-up potties Cotton wool balls

4 Box 2. Specific and non-specific symptoms of UTI in children Specific symptoms Dysuria Enuresis Urgency Loin pain Frequency of micturition Non-specific symptoms Diarrhoea and vomiting Prolonged neonatal jaundice Irritability Lethargy Poor feeding Failure to thrive Abdominal pain Fever REFERENCES Ahmad T et al (1991) Urine collection from disposable nappies. Lancet. 338, 8768, Al-Orifi F et al (2000) Urine culture from bag specimens in young children: are the risks too high? The Journal of Pediatrics. 137, 2, American Academy of Pediatrics (1982) Simplified urinary microscopy to detect significant bacteriuria. Pediatrics. 70, 1, Barratt T et al (1996) Pediatric Nephrology. Fourth Edition. Baltimore MD, Lippincott Williams and Wilkins. Bayer 1998 A Practical Guide to Urine Analysis. Newbury, Bayer plc Diagnostic Division. Beeram M, Dhanireddy R (1990) Urinalysis: direct versus diaper collection. Clinical Pediatrics. 30, 5, Benador D et al (1997) Are younger children at highest risk of renal sequelae after pyelonephritis? Lancet. 349,9044, Bergstrom T (1972) Sex differences in childhood urinary tract infection. Archives of Disease in Childhood. 47, 252, Bonadio W (1990) Evaluation and management of serious bacterial infections in the febrile young infant. Pediatric Infectious Disease Journal. 9, 12, Buys H et al (1994) Suprapubic aspiration under ultrasound guidance in children with fever of undiagnosed cause. British Medical Journal. 308, 6930, Collier J (1997) The management of urinary tract infection in children. Drug and Therapeutics Bulletin. 35, 9, Dick P, Feldman W (1996) Routine diagnostic imaging for childhood urinary tract infections: a systematic overview. Journal of Pediatrics. 128, 1, Cotton wool balls These can be used to collect urine for a variety of biochemical markers (Roberts and Lucas 1985); however, there is evidence to suggest that the manufacturing process produces fatty acids that are antibacterial (Shea 1992) and render them unsatisfactory for microbiological processing. TIME OUT 3 The important criteria for urine collection methods are that they obtain a urine specimen that includes any evidence of infection, are relatively not traumatic for the child, practical to conduct (for example, in the community) and reasonably inexpensive. Create a table using these headings and 'score' the urine collection methods described above. Which of these criteria appear to dominate current local practice and what are the implications for child health? Specific and non-specific signs and symptoms of UTI Adults developing UTIs can clearly verbalise the characteristic signs and symptoms of UTI: urinary frequency, dysuria and urgency to micturate. This is not so in the case of children. This is further complicated by the development of non-specific symptoms, as it appears that the younger the patient, the less likely the symptoms are related to the urinary tract. This might be a compounding reason for the delay in diagnosis in the very young. Box 2 lists the specific and non-specific symptoms related to UTI in children (Poole 1999). When the signs and symptoms are indicative of UTI in a child and a clean uncontaminated urine sample has been obtained, the nurse is able to perform urinalysis. This is a simple test that can aid the diagnosis of UTI. TIME OUT 4 This Time Out offers you a choice. Either construct two to three questions that you believe would help you to ascertain the urinary symptoms that a nursery-age child was experiencing. For example, how would you ask about dysuria? Ask a colleague to evaluate the complexity of your language and revise as necessary. Or make a list of all the abnormalities that you believe can be detected using urine reagent strips. Reflect on how you would explain each of these abnormalities to an anxious mother standing beside you. Urine analysis Urine analysis is one of the first clinical skills nurses are taught to perform. It is a simple, quick and reliable method of monitoring known disease and identifying new illness. Urine testing is not a new concept. As early as 1500 BC Egyptian writings refer to polyuria. By the 7th century AD Protospharis suggested diagnosis through colour. By 1830 routine urine analysis consisted of visual observation, a test for protein and a test for urea. Ensuing years have seen the refinement of chemical reagent testing through the application of a variety of tablets. By the middle of 1960 developments led to the use of chemically impregnated multi-sticks in the clinical area, the so-called 'near patient' testing method. The past four decades have seen further development of the near patient testing methods and this has culminated in a range of automated instruments to enhance the quality of urine testing results (Bayer 1998). Infections of the urinary tract usually produce pus cells that release an esterase (leucocyte esterase) which reacts with the leukocyte reagent pad. The presence of leukocytes in the urine is therefore an indication of UTI. Nitrite is not normally present in urine. If nitrite is positive on dip-testing, this is indicative of bacteriuria. Nitrites are produced in urine by the bacterial breakdown of dietary nitrate, which is a waste product of protein metabolism. The majority of urinary pathogens reduce urinary nitrate to nitrite, except for certain pseudomonads and streptococcus Group B (Poole 1999). According to Woodward and Griffiths (1993), the absence of both leucocytes and nitrite in a fresh urine sample confirms its sterility, while the presence of one of the markers indicates a possible UTI, and positive detection of leucocytes and nitrite confirms infected urine. Evidence suggests that the conversion of nitrate to nitrite bacteria requires at least a four-hour incubation period in the bladder (Bayer 1998). Therefore, it is not uncommon for non-toilettrained infants and children to have nitrite negative urine test results when they might later be found to have a nitrite forming UTI following urine culture results. According to Powell et al (1987), this suggests that frequency of micturition in patients with UTI could be a possible cause of false negative nitrite reactions. Powell et al also report considerable difference in the sensitivity of the nitrite test as an indicator of UTI in patients with both symptomatic and asymptomatic infection. It is not uncommon for haematuria to be detected in patients who have a UTI. Haematuria is therefore a useful marker of infection and/or urinary tract disease. Proteinuria can also be evident in patients with UTI. While it is less significant if detected in isolation,

5 proteinuria might be a marker of upper urinary tract disease, which would warrant further investigation. Urine microscopy Microscopy on uncentrifuged fresh urine samples at the bedside has been shown to be useful in speeding up the diagnosis of UTI (AAP 1982, Poole 1999, Vickers et al 1991). Urine microscopy can be reliably performed within a minute by an experienced microscopist. Sediment, such as red blood cells, white blood cells, bacteria, casts and crystals, can be identified. This method of urine assessment is also useful in determining whether the urine sample is likely to be contaminated. For example, the presence of squamous epithelial cells is highly indicative of contamination and suggests the need for repeat sampling. If urine microscopy reveals a mixture of organisms (rods, chains of cocci or single cocci) this is also a high indicator of a contaminated urine sample. It is not uncommon to find cotton fibres, talcum powder or oil droplets (from barrier creams) in paediatric urine samples, which suggest a poor quality urine sample and the need for a repeat sample. Urine samples should be processed for culture if they contain >ten white blood cells with or without organisms, >100 white blood cells without organisms, and if organisms alone are seen (RCP 1991). White blood cell counts are known to reduce over time due to cell lysis (Bayer 1998). Urine culture In the majority of laboratories the main criterion for the confirmation of UTI is the presence of a pure growth of >105 colony forming units per ml on a urine culture plate. This is based on the work of Kass (1956) who undertook a prospective epidemiological study of asymptomatic bacteriuria in adult women with Gram-negative infections. Kass s (1956) criterion has been challenged in the paediatric arena (Buys et al 1994, Hansson et al 1998, Hellerstein 1994). Evidence is emerging that lower bacterial counts might be significant in young children, especially in children who are not toilettrained (Buys et al 1994, Hansson et al 1998, Hellerstein 1994). TIME OUT 5 As previously indicated some children are at an increased risk of developing permanent upper urinary tract damage following UTI. What underlying renal tract abnormalities place this group of children at higher risk than those children with anatomically normal urinary tracts? Management of UTI following diagnosis The primary aim in treating UTI is to avoid delay in starting antibiotic therapy, thus minimising the risk of associated renal scarring. Infants are at high risk of developing sepsis, electrolyte abnormalities and shock as serious sequelae of UTI. This age group is, therefore, ideally treated with intravenous antibiotics, which should be started before culture results are available. Gentamicin or ampicillin are the drugs of choice. However, a reduced dosing regimen might be required in infants known to have renal scarring, and it is essential that gentamicin levels are monitored. This ensures that therapeutic levels are achieved and reduces the risks of renal toxicity and ototoxicity (damage to the eighth cranial nerve causing deafness). Alterations in antibiotic therapy might be required when urine culture results are available. Antibiotic regimes may vary in differing hospital and community settings. Oral antibiotics are usually effective in the majority of children, provided the child is not vomiting. The most common drugs for treating UTI in children are trimethoprim, cephalexin, nitrofurantoin, and ampicillin (co-amoxiclav) (Barratt et al 1996). Because of their tolerance and wide use, antibiotics such as trimethoprim are increasingly becoming resistant to common pathogens. It has been reported that up to 20 per cent of E. coli isolates are resistant to trimethoprim (Collier 1997). Children with renal tract abnormality who are diagnosed with UTI are said to have 'complicated UTI', which usually involves the upper urinary tract (pyelonephritis). Children with normal urinary tracts who experience UTI are said to have uncomplicated UTI (cystitis). Children with complicated UTI should receive antibiotic therapy for a minimum of ten days (RCP 1991). However, children with uncomplicated UTI will be free from symptoms after one or two doses of an antibiotic, therefore treatment for three to five days might be sufficient (Tran et al 2001). Concern has been raised over the use of prophylactic antibiotics as this is a variable and nonevidence-based area. However, low-dose antibacterial prophylaxis should be commenced for all children following confirmation of their first UTI. This prophylaxis should be started following completion of their treatment dose of antibiotic therapy. It should be continued until radiological assessment of their urinary system has been undertaken. If normal renal tract anatomy is identified, prophylaxis is usually stopped. However, children who are diagnosed as having VUR (bilateral or unilateral), neuropathic bladders, posterior urethral valves, Drug and Therapeutics Bulletin (1997) The management of urinary tract infection in children. Drug and Therapeutics Bulletin. 35, 9, Farrell M (2002) A method comparison study to assess the reliability of urine collection pads as a means of obtaining urine specimens from non-toilet-trained children for microbiological examination. Journal of Advanced Nursing. 37, 4, Feasey S (1999) Are Newcastle urine collection pads suitable as a means of collecting specimens from infants? Paediatric Nursing. 11, 9, Hansson S et al (1998) Low bacterial counts in infants with urinary tract infection. Journal of Pediatrics. 132, 1, Hansson S, Jodal U (1996) Section VIII: urinary tract disease. 52. Urinary tract infection. In Barratt T et al (Eds) Pediatric Nephrology. Fourth edition. Baltimore, Lippincott Williams & Wilkins. Hellerstein S (1994) Evolving concepts in the evaluation of the child with a urinary tract infection. Journal of Pediatrics. 124, 4, Hoberman A et al (1994) Pyuria and bacteriuria in urine specimens obtained by catheter from young children with fever. Journal of Pediatrics. 124, 4, James Ellison M et al (1994) Urinary tract infection, vesico-ureteric reflux and pyelonephritis. Pediatric Adolescent Medicine. 5, Kass E (1956) Asymptomatic infections of the urinary tract. Transactions Association of American Physicians. 69, Lee P, Verrier Jones K (1991) Urinary tract infection in febrile convulsions. Archives of Disease in Childhood. 66, 11, Lewis J (1998) Clean-catch versus urine collection pads: a prospective trial. Paediatric Nursing. 10, 19, Macfarlane P et al (1999) Pad urine collection for early childhood urinary tract infection. Lancet. 354, 9178, 571. Mahant S et al (2001) Timing of voiding cystourethrogram in the investigation of urinary tract infections in children. Journal of Pediatrics. 139, 4, Marild S et al (1989) Fever, bacteriuria and concomitant disease in children with urinary tract infection. Paediatric Infectious Disease Journal. 8,1, McKerrow W et al (1984) Urinary tract infection in children. British Medical Journal Clinical Research Edition. 289, 6440, Miller K (1996) Urinary tract infections; children are not little adults. Pediatric Nursing. 22, 6, Poole C (1999) The use of urinary dipstix in children with high-risk renal tracts. British Journal of Nursing. 8, 8,

6 Powell H et al (1987) Urinary nitrate in symptomatic and asymptomatic urinary infection. Archives of Disease in Childhood. 62, Ramage I et al (1999) Accuracy of clean-catch urine collection in infancy. Turkish Journal of Pediatrics. 135,6, Rees J et al (1996) Collection of urine from washed-up potties. Lancet. 348, 9021, 197. Risdon R (1993) The small scarred kidney in childhood. Pediatric Nephrology. 7, 4, Roberts S, Lucas A (1992) A nappy collection method for measuring urinary constituents and 24-hour urine output in infants. Archives of Disease in Childhood. 60, 11, Royal College of Physicians (1991) Guidelines for the Management of Acute Urinary Tract Infection in Childhood. Report of a Working Group of the Research Unit. Journal of Royal College of Physicians in London. 25, 1, Shea Y (1992) Specimen collection and transport. In Isenberg H (Eds) Clinical Microbiology Procedures Handbook. Washington, American Society for Microbiology. Sreenarasimhaiah S, Hellerstein S (1998) Urinary tract infections per se do not cause end-stage kidney disease. Pediatric Nephrology. 12,3, Stark H (1997) Urinary tract infections in girls: the cost-effectiveness of currently recommended investigation routines. Pediatric Nephrology. 11, 2, Tran D et al (2001) Short-course versus conventional length antimicrobial therapy for uncomplicated lower urinary tract infection in children: a meta-analysis of 1279 patients. Journal of Pediatrics. 139, 1, Vernon S (1995) Urine collection from infants: a reliable method. Paediatric Nursing. 7, 6, Vernon S et al (1994) Urine collection on sanitary towels. Lancet. 344, 8922, 612. Verrier Jones K, Newall R (2000) Urinary Tract Infection in Infancy and Early Childhood. Proceedings of a workshop. Stoke Poges. November Vickers D et al (1991) Diagnosis of urinary tract infection in children: fresh urine microscopy or culture? Lancet. 338, 8770, Waddington P, Watson A (1997) Which urine collection bag? Paediatric Nursing. 9, 2, Williams G et al (2001) Antibiotics for the prevention of urinary tract infection in children: a systematic review of randomized controlled trials. Journal of Pediatrics. 138, 6, Woodward M, Griffiths D (1993) Use of dip-sticks for routine analysis of urine from children with acute abdominal pain. British Medical Journal. 306, 6891,1512. Box 3. Royal College of Physicians guidelines for renal investigations following childhood UTI Children under one year: Ultrasound examination of the kidneys and bladder Plain abdominal X-ray Micturating cystourethrogram Dimercaptosuccinic acid (carried out at least three months after the infection has been treated) Children between one and seven years: Ultrasound examination of the kidneys and bladder Dimercaptosuccinic acid (as above) (RCP 1991) solitary refluxing kidneys, hydro-nephrosis or pelviureteric junction obstruction are at increased risk of developing recurrent urinary tract infections and renal scars. This group of patients might continue prophylactic antibiotics for up to two years or more. There is disagreement among healthcare professionals as to the mean duration of prophylaxis. Use of prophylaxis is thought to reduce the recurrence rate of UTI and, therefore, has the potential to reduce renal scarring. However, some infants who demonstrate VUR are born with renal scars. This suggests that reflux alone might be responsible for scar development. This raises the question of the usefulness of long-term prophylaxis. Williams et al (2001) undertook a systematic review of the literature and discovered that only five comprehensive studies had been undertaken to assess the outcome of prophylaxis. They identified methodologic and applicability problems with the published trials and recommended that further randomised, placebo-controlled trials should be undertaken. Diagnostic imaging following childhood UTI The main aim of imaging the urinary tract following a first confirmed UTI in childhood is to identify those patients who are at an increased risk of developing progressive renal damage. Four key radiological imaging techniques are generally undertaken, however the timing of these investigations following the index UTI is an issue for debate (Dick and Feldman 1996, Mahant et al 2001) as is the need for such invasive tests (Stark 1997). Box 3 outlines the Royal College of Physicians' guidelines on the minimum investigations for children with UTI. Renal ultrasound scan This simple non-invasive test should be performed as a minimum for children following their first UTI. It is effective in the detection of dilatation of the upper and lower urinary tract, can reveal severe renal scarring, identify duplex kidneys, solitary kidneys, horseshoe kidneys, estimation of renal size, and can be useful in the detection of major bladder anomaly. This method does not expose the child to radiation, as ultrasound waves are used. Micturating cystourethrogram This test should only be performed when the urine is sterile. It is an invasive test that can be extremely unpleasant for some children as it requires urethral catheterisation to allow radio opaque dye to be instilled into the child s bladder. The child s bladder is filled with dye, which stimulates micturition in the non-toilettrained age group. Older, co-operative children are asked to micturate while they are lying down on the X-ray table. While micturition takes place a series of X-rays are taken to identify any VUR or bladder obstruction. Dimercaptosuccinic acid This is a radioactive isotope study that allows the assessment of renal scars, differential renal function, excretory function and details of anatomy. It is also useful in the identification of ectopic kidneys and confirmation of solitary kidneys. The amount of radiation in the isotope, which is given as an injection, is small and quickly excreted. Plain abdominal X-ray This investigation is simple to perform and non-invasive, but it is not as productive as the other investigations in yielding abnormalities. It is, however, a useful method in visualisation of the spinal column and thus has a role to play in the identification of neurological abnormalities such as spina bifida. It is also useful in the detection of some urinary calculi (stones). Conclusion Childhood UTI is a common finding, however, confirmation of diagnosis is dependent on the collection of a clean uncontaminated urine sample. Paediatric nurses play an important role in the collection of urine samples from this group of patients and have a key educative role for children and their parents. Parents commonly ask nursing staff questions related to all aspects of urine infection, therefore, nurses should be able to provide reliable evidencebased answers TIME OUT 6 Now that you have completed the article, you might like to write a practice profile. Guidelines to help you are on page 55.