Primary nocturnal enuresis is common, affecting approximately 15% to 20% of children at 5 years of age and decreasing spontaneously thereafter (Elder, 2011f). It occurs more frequently in boys and in children with a family history of bed-wetting. Most children eventually outgrow bed-wetting without therapeutic intervention. Some children have diurnal (daytime) enuresis without nocturnal enuresis. Waiting until the last minute to void and not being able to access a bathroom quickly may be a factor in diurnal enuresis, but the main cause is an overactive bladder, a condition in which the child experiences bladder spasms or increased urgency (Elder, 2011f). Primary enuresis often resolves spontaneously.

Treatment of primary nocturnal enuresis may begin with general interventions, such as explaining theories underlying the problem in terms the child can understand. The child is reassured that, with assistance, the problem can resolve. Commonsense approaches of limiting fluids after supper and voiding just before bedtime are encouraged. Diet modifications include avoiding extraneous sugar and caffeine intake after 4 PM, because these can act as bladder stimulants as well as diuretics (Elder, 2011f). Also, the child can be trained to use imagery; thinking about what a full bladder feels like and picturing waking up and going to the bathroom. This imagery is done as the child lies in bed before drifting off to sleep. The child should keep a record of the number of dry and wet nights to measure progress.

Reward systems assume that bed-wetting is a voluntary behavior and have had varying results for the child with primary nocturnal enuresis. The child may be given a roll of favorite stickers to mark the dry nights on the calendar. The family decides on a special reward or outing when the child has achieved a certain number of consecutive dry nights.

Behavioral conditioning with use of alarms has been successful in the older child with nocturnal enuresis. A device worn on the child’s pajamas contains a moisture-sensitive alarm. As the child starts to void, the alarm goes off, awakening the child. The alarm system may need to be used consistently over 15 weeks for resolution.

Desmopressin acetate (deamino-d-arginine vasopressin [DDAVP]) has also been helpful because of its antidiuretic effect. Desmopressin acetate is given as a tablet and is taken at bedtime. Pharmacologic treatment is not recommended for children under 6 years of age.

Voiding frequently to keep urine volume in the bladder low may benefit children who are affected by uninhibited bladder contractions during the day. The use of an anticholinergic such as oxybutynin chloride, which relaxes the smooth muscle of the bladder, can be helpful for children with diurnal enuresis related to underlying bladder instability or small bladder capacity. Biofeedback may also help children with diurnal enuresis, particularly those with dysfunctional voiding.

Fecal bacteria cause most UTIs. Escherichia coli are the bacteria implicated in 75% to 90% of all UTIs in girls (Elder, 2011d). Other bacteria known to cause UTIs are group B streptococci, Klebsiella pneumoniae, Proteus species, Enterobacter species, enterococci, and Staphylococcus species. Viruses and fungi, specifically Candida species, can rarely cause infections.

The following conditions predispose the infant or child to UTI:

The overall prevalence of UTIs in the United States is 3% to 5% in girls and 1% in boys. In girls, the first UTI generally occurs before 5 years of age with an increase in the number of cases seen during infancy and toilet training. For boys, most UTIs occur during the first year of life with a higher incidence in uncircumcised infants (Elder, 2011d). Symptoms of a UTI may be missed in children with coexisting gastrointestinal or respiratory symptoms, so UTI should be considered as a cause in any child with significant illness, especially if febrile (National Institute for Health and Clinical Excellence [NICE], 2007). It is important to diagnose UTIs quickly, as an ascending UTI can result in renal scarring. VUR is a frequently seen underlying anatomic abnormality in children with UTIs.

UTIs are more prevalent in white, Asian, and Hispanic children and less prevalent in African-American children (Shaikh, Morone, Lopez, et al., 2007). Breastfeeding has been found to significantly reduce the risk of UTIs in both boys and girls because of the protective factors observed in human milk that prevent microbial attachment to the mucosa (Marild, Hansson, Jodal, et al., 2004).

Clinical manifestations of UTI vary widely; factors include the child’s age, sex, underlying anatomic or neurologic abnormalities, and frequency of recurrence. Signs in the young child and infant are more vague and nonspecific. Fever (100.4° F [38° C]) without a known focus for infection in infants and young children 2 to 24 months of age suggests a UTI. Suprapubic tenderness may be an accompanying sign in an infant. Signs and symptoms in a verbal child include abdominal pain, frequency, urgency, and dysuria (Shaikh et al., 2007).

An abdominal mass can suggest hydronephrosis in an infant (Elder, 2011c). Other signs and symptoms of hydronephrosis are similar to those for an infant with a UTI (Box 44-1).

PATHOPHYSIOLOGY

Vesicoureteral Reflux

A valvelike mechanism at the junction of the ureter and bladder prevents urine reflux into the ureters. As urine fills the bladder or as the bladder contracts during voiding, pressure in the bladder occludes the opening to the ureter. When a defect occurs at the vesicoureteral junction, vesicoureteral reflux (VUR) results. The defect at the vesicoureteral junction is considered a congenital abnormality, although transitory VUR associated with a lower urinary tract infection (UTI) is also possible.

In VUR, two mechanisms contribute to UTI. Bacteria in the urine can be carried up to the kidney, causing pyelonephritis and renal damage with scarring. Also, when urine reflux into the lower ureter occurs, urine can return to the bladder, leaving urine residual that becomes a medium for bacterial growth.

The severity of VUR determines the potential risk for pyelonephritis and kidney damage. The International Classification of Reflux grades reflux on a scale of I through V. Grade I describes reflux into the ureter only with no dilation. Grade V, the most severe, includes gross dilation and reflux involving the kidney.

Urine culture is the single determining diagnostic study for a UTI. Any bacterial growth of a single-strain bacterium exceeding 100,000 colony-forming units/mL in a clean-catch urine specimen establishes a diagnosis of UTI. Obtaining a sterile urine sample is difficult in children, especially children who are not yet toilet trained. A child who can void on demand can provide a midstream clean-catch urine specimen. In infants and children who are not toilet trained, a sterile pediatric urine collection bag attached to the perineum can collect a urine specimen (see Chapter 37). Collecting urine by this method is less invasive but is clearly not as accurate for obtaining a culture as by other methods, and the urine specimen must be plated as quickly as possible. If the urine cannot be plated within 10 minutes of collection, it should be refrigerated.

When accurate determination of bacteria is the goal, more intrusive methods of bladder catheterization (see Chapter 37) or suprapubic aspiration are the collection methods of choice. If suprapubic aspiration is necessary, the area above the pubis is cleaned with an antiseptic solution, a needle attached to a syringe is inserted by the physician at a 90-degree angle into the bladder, and urine is aspirated. If catheterization or suprapubic aspiration is used to obtain a urine culture, the growth of any bacteria indicates infection.

More intensive evaluation for underlying structural abnormalities is necessary for certain infants and children with UTIs. Evaluative studies include ultrasonography to detect kidney dilation resulting from obstruction and a voiding cystourethrography or radionuclide cystography to detect VUR.

A 3- to 5-day course of oral antibiotics is the treatment of choice for an uncomplicated UTI without systemic symptoms (Elder, 2011d). The antibiotic chosen should be one to which the specific bacterium (identified by culture) is sensitive, should be easily administered, and should have minimal adverse effects. Oral trimethoprim-sulfamethoxazole, nitrofurantoin, and cephalosporins are frequently used.

Children with pyelonephritis often require initial treatment with parenteral antibiotics followed by oral antibiotic treatment. The older child who does not need hospitalization can receive daily intramuscular ceftriaxone for 1 to 2 days, followed by 10 to 14 days of oral antibiotics. Infants and children admitted to the hospital for treatment usually receive IV ampicillin and a cephalosporin or an aminoglycoside (e.g., gentamicin). Some children are treated with a cephalosporin alone. Oral antibiotics may follow this initial treatment with parenteral antibiotics.

When anatomic abnormalities are detected or UTIs recur, prophylactic antibiotic therapy might be initiated, although recent studies suggest that the risk for antibiotic resistance may be higher than the therapeutic value of prophylaxis (Agency for Healthcare Research and Quality, 2008). Prophylactic antibiotics are sometimes given to children after their initial course of treatment while they are waiting for imaging studies to confirm an underlying structural abnormality.

Because the majority of children with grades I through III VUR have a spontaneous resolution of the reflux, most physicians choose nonsurgical management of this condition (Elder, 2011e). Children are often given prophylactic antibiotics, although this has become controversial (Montini, Rigon, Zuchetta, et al., 2008), and screened for UTI every 2 to 4 months and when febrile. A voiding cystourethrogram (VCUG) is performed every 12 to 18 months to monitor resolution of reflux (Elder, 2011e).

First-line surgical treatment for children with persistent grade I through III VUR is the endoscopic injection of bulking material into the submucosa of the affected ureter. The material, Deflux injectable gel, builds a protective wall inside the ureter to prevent the backflow of urine. Open surgical repair, reimplantation of the ureter into the bladder, is indicated for children who continue to have reflux and breakthrough UTIs despite antibiotic therapy, severe grade IV or V reflux, or two to three failed Deflux treatments (Elder, 2011e).