5: Urinary tract infections and vesicoureteral reflux Flashcards
What percentage of febrile infections in infants and children are caused by urinary tract infection (UTI)?
a. Up to 2%
b. Up to 5%
c. Up to 8%
d. Up to 10%
c. Up to 8%
Explanation: According to the information provided, up to 8% of febrile infections in infants and children are caused by UTIs.
What symptoms and signs are associated with a “toxic” appearing febrile child?
a. Rash and headache
b. Stomach pain and vomiting
c. Irritability, lethargy, abnormal breathing, tachycardia, and cyanosis
d. Joint pain and muscle weakness
c. Irritability, lethargy, abnormal breathing, tachycardia, and cyanosis
Explanation: According to the information provided, some symptoms and signs of toxicity in a febrile child include irritability, lethargy, abnormal breathing, tachycardia, and cyanosis.
What is the recommended evaluation and treatment for a child with a rectal temperature higher than 38°C?
a. No evaluation or treatment is needed if the child appears healthy.
b. The child should be evaluated for a UTI only if another source of fever and infection cannot be identified.
c. The child should be evaluated for a UTI regardless of whether another source of fever and infection has been identified.
d. The child should be treated with antibiotics for a UTI without further evaluation.
c. The child should be evaluated for a UTI regardless of whether another source of fever and infection has been identified.
Explanation: According to the information provided, the clinician must consider the possibility of a UTI in any febrile infant, even if another source of fever and infection has been identified. A summary of the evaluation and treatment of a child with a rectal temperature higher than 38°C is provided in Fig. 5.1.
What is the current diagnostic guideline for diagnosing a significant UTI in children aged 2-24 months?
a. A blood test showing elevated white blood cell count and a fever
b. A positive urine culture with any level of bacterial growth
c. A urinalysis with pyuria and/or bacteriuria and at least 100,000 CFU/mL of a uropathogen cultured from a urine specimen obtained through urethral catheterization or suprapubic aspiration
d. A urinalysis with pyuria and/or bacteriuria and at least 50,000 CFU/mL of a uropathogen cultured from a urine specimen obtained through urethral catheterization or suprapubic aspiration
d. A urinalysis with pyuria and/or bacteriuria and at least 50,000 CFU/mL of a uropathogen cultured from a urine specimen obtained through urethral catheterization or suprapubic aspiration.
Explanation: According to the information provided, the current diagnostic guideline for diagnosing a significant UTI in children aged 2-24 months from the American Academy of Pediatrics (AAP) requires a urinalysis (UA) with pyuria and/or bacteriuria and at least 50,000 CFU/mL of a uropathogen cultured from a urine specimen obtained through urethral catheterization or suprapubic aspiration.
Fig. 5.2 (A) Uncomplicated urinary tract infections begin when uropathogens that normally reside in the gut colonize the urethra (Step 1). These bacteria then migrate to the bladder (Step 2), where they colonize and invade superficial umbrella cells within the urothelium (Step 3). Innate host inflammatory responses begin to clear bacteria (Step 4). Some bacteria, though, evade the immune system, and these bacteria may then multiply (Step 5) and form a biofilm (Step 6). These bacteria produce toxins and proteases that induce host cell damage (Step 7). They also release nutrients that promote bacterial survival and allow the bacteria to ascend to the kidneys (Step 8). Kidney colonization (Step 9) results in bacterial toxin production and host tissue damage (Step 10). UTIs can ultimately progress to bacteremia if the pathogen crosses the tubular epithelial barrier in the kidneys (Step 11). (B) Uropathogens that cause complicated UTIs follow the same initial steps, including periurethral colonization (Step 1) and migration to the bladder (Step 2). However, for the pathogens to cause infection, the bladder must be compromised. The most common cause of a compromised bladder is an indwelling urinary catheter. There is a robust immune response induced by catheterization (Step 3), resulting in fibrinogen accumulation along the catheter, providing an ideal environment for the attachment of uropathogens that express fibrinogen-binding proteins. This infection induces neutrophil infiltration (Step 4), but after their initial attachment to the fibrinogen-coated catheters, the bacteria multiply (Step 5), form biofilms (Step 6), promote epithelial damage (Step 7), and can seed infection of the kidneys (Steps 8 and 9), where toxin production induces tissue damage (Step 10). These uropathogens can also progress to bacteremia by crossing the tubular epithelial cell barrier (Step 11).
When are urinary tract infections (UTIs) more prevalent in boys than in girls?
a. During the first year of life
b. Between ages 1 and 6
c. Between ages 6 and 10
d. After age 10
a. During the first year of life
Explanation: According to the information provided, the only time that UTIs are more prevalent in boys than in girls is at an age younger than 1 year. About 2% of boys and 0.7% of girls experience a UTI during the first year of life.
How much does circumcision reduce the risk of UTI development in the first 6 months of life?
a. By 2-fold
b. By 5-fold
c. By 10-fold
d. By 20-fold
c. By 10-fold
Explanation: According to the information provided, circumcision reduces UTI development in the first 6 months of life by almost 10-fold.
What percentage of children have vesicoureteral reflux (VUR) after their first episode of UTI?
a. 1%-2%
b. 10%-15%
c. 25%-40%
d. 50%-70%
c. 25%-40%
Explanation: According to the information provided, VUR occurs in 1%–2% of all newborns, but it is found in 25%–40% of children after their first episode of UTI.
Does VUR occur in all children with pyelonephritis?
a. Yes, all children with pyelonephritis have VUR
b. No, VUR is not associated with pyelonephritis
c. Approximately 50%–70% of children with pyelonephritis have VUR
d. It is not clear from the information provided.
c. Approximately 50%–70% of children with pyelonephritis have VUR
Explanation: According to the information provided, VUR facilitates ascent of bacteria from the bladder to the kidney; however, approximately 50%–70% of children with pyelonephritis will not have VUR.
Table 5.1 International Classification of Vesicoureteral Reflux
What is bladder and bowel dysfunction (BBD) and how does it affect the risk of UTI?
a. BBD is a bacterial infection that affects the urinary system, and it increases the risk of UTI.
b. BBD is a structural abnormality of the urinary system, and it increases the risk of UTI.
c. BBD is a functional abnormality of the bladder and bowel, and it predisposes to UTI.
d. BBD is a neurological disorder that affects the bladder and bowel, and it increases the risk of UTI.
c. BBD is a functional abnormality of the bladder and bowel, and it predisposes to UTI.
Explanation: According to the information provided, BBD predisposes to UTI, and treatment of BBD reduces recurrent UTIs as well as incontinence and VUR.
What is catheter-associated UTI (CAUTI) and how does it affect the risk of UTI?
a. CAUTI is a bacterial infection that affects the urinary system, and it increases the risk of UTI.
b. CAUTI is a structural abnormality of the urinary system, and it increases the risk of UTI.
c. CAUTI is a functional abnormality of the bladder and bowel, and it predisposes to UTI.
d. CAUTI is a nosocomial infection that occurs with the use of urinary catheters, and it increases the risk of UTI.
d. CAUTI is a nosocomial infection that occurs with the use of urinary catheters, and it increases the risk of UTI.
Explanation: According to the information provided, catheter-associated UTI (CAUTI) is the most common nosocomial infection, and the risk of UTI increases with the duration of the catheter. Removal of urethral catheters in hospitalized patients is recommended as soon as possible.
Why are antibiotics often unable to eradicate bacteria within a biofilm?
a. Because bacteria within a biofilm are not susceptible to antibiotics
b. Because bacteria within a biofilm produce a self-developed polymeric matrix that protects them from antibiotics
c. Because bacteria within a biofilm are in a dormant state and are not affected by antibiotics
d. Because antibiotics are not able to penetrate the self-developed polymeric matrix of a biofilm
d. Because antibiotics are not able to penetrate the self-developed polymeric matrix of a biofilm
Explanation: According to the information provided, antibiotics are often unable to eradicate bacteria within a biofilm because they are not able to penetrate the self-developed polymeric matrix of a biofilm.
What are biofilms?
a. Communities of living organisms that do not produce a polymeric matrix
b. Communities of inert surfaces that are not encapsulated
c. Communities of microorganisms encapsulated with a self-developed polymeric matrix and adherent to a living or inert surface
d. Communities of microorganisms that do not produce a polymeric matrix
c. Communities of microorganisms encapsulated with a self-developed polymeric matrix and adherent to a living or inert surface
Explanation: According to the information provided, biofilms are communities of microorganisms encapsulated with a self-developed polymeric matrix and adherent to either a living or inert surface.
Which of the following is true about asymptomatic bacteriuria (ASB) in children?
a. It occurs in 50% of preschool girls
b. It requires antibiotics to be treated
c. It is associated with a high risk of recurrent symptomatic infections, renal damage, or impaired renal growth
d. Infants with ASB are at risk for developing significant UTIs
d. Infants with ASB are at risk for developing significant UTIs and should be treated with antimicrobial therapy and imaged to evaluate for any congenital abnormalities. ASB is defined as the presence of two consecutive urine specimens yielding positive cultures of the same uropathogen, and it does not require antibiotics in most cases, as children with ASB do not appear to be at any risk for recurrent symptomatic infections, renal damage, or impaired renal growth.
FIG. 5.3 Computed tomography scan demonstrating acute focal pyelonephritis (lobar nephronia).
What are some nonspecific symptoms that may indicate a UTI in children?
a. Coughing and sneezing
b. Headaches and dizziness
c. Fever and irritability
d. Muscle weakness and fatigue
c. Fever and irritability are nonspecific symptoms that may indicate a UTI in children. Other possible symptoms may include poor feeding, jaundice, failure to thrive, vomiting, diarrhea, abdominal distention, or foul-smelling urine.
Which of the following symptoms are most useful in predicting a UTI in children younger than 2 years of age?
a. Abdominal pain and back pain
b. Dysuria and urinary frequency
c. History of a previous UTI and suprapubic tenderness
d. Incontinence and foul-smelling urine
c. History of a previous UTI, suprapubic tenderness, fever higher than 40°C, or an uncircumcised penis are the most useful symptoms and signs in predicting a UTI in children younger than 2 years of age.
What are some classic UTI symptoms in older children?
a. Fever and irritability
b. Poor feeding and jaundice
c. Abdominal pain and back pain
d. Vomiting and diarrhea
c. Abdominal pain, back pain, dysuria, urinary frequency, and incontinence are classic UTI symptoms in older children.
What should be considered in older children and adolescents with symptoms of urethritis?
a. The possibility of sexually transmitted diseases
b. The possibility of food poisoning
c. The possibility of an allergic reaction
d. The possibility of a viral infection
a. The possibility of sexually transmitted diseases such as Neisseria gonorrhoeae, Chlamydia trachomatis, or Ureaplasma urealyticum should be considered in older children and adolescents with symptoms of urethritis.
What should be evaluated during the examination of the external genitalia in girls?
a. Signs of trauma
b. Local inflammation
c. Urethral meatal stenosis or discharge
d. All of the above
d. During the examination of the external genitalia in girls, signs of trauma, local inflammation, urethral meatal stenosis or discharge, phimosis, foreign body, and anatomic abnormalities such as an ectopic ureteral orifice or urethral mass from a prolapsing ureterocele should be evaluated.
What is the most reliable urine collection method in an older girl or a circumcised boy?
a. Urine collection bag
b. Clean-catch midstream urine sample
c. Catheterization
d. Suprapubic aspiration
b. A clean-catch midstream urine sample is the most reliable urine collection method in an older girl or a circumcised boy. For nontoilet-trained febrile children younger than 2 years of age, the AAP guidelines recommend catheterization or suprapubic aspiration (SPA).
What is the sensitivity and specificity of the nitrite test in detecting UTIs?
a. Sensitivity of 50% and specificity of 64%-92%
b. Sensitivity of 50% and specificity of 98%
c. Sensitivity of 80% and specificity of 64%-92%
d. Sensitivity of 80% and specificity of 98%
b. The sensitivity of the nitrite test is 50%, and the specificity is very high at 98%, meaning a positive nitrite test likely reflects a true UTI. The sensitivity of leukocyte esterase for detecting UTI is estimated at 80% with specificity ranging from 64%–92%.
What is the recommended imaging strategy for all children less than 2 years of age with a febrile UTI according to revised AAP guidelines?
a. Routine voiding cystourethrogram (VCUG)
b. Routine renal ultrasound
c. Both VCUG and renal ultrasound
d. No imaging is recommended
b. Routine renal ultrasound.
Explanation: According to revised AAP guidelines, a renal ultrasound is recommended for all children less than 2 years of age with a febrile UTI, but a VCUG is not recommended if the ultrasound is normal.
When is a VCUG recommended following a first febrile UTI according to the Section of Urology of the AAP?
a. Never
b. Always
c. Only if an RBUS demonstrates structural renal anomalies
d. Only if the ultrasound is abnormal
c. Only if an RBUS demonstrates structural renal anomalies.
Explanation: The Section of Urology of the AAP recommends that a VCUG remain an accepted option following a first febrile UTI, but only if an RBUS demonstrates structural renal anomalies.
What is the sensitivity of RBUS for the detection of VUR, even in children with high grades of VUR?
a. Very high
b. High
c. Moderate
d. Very low
Answer: d. Very low.
Explanation: RBUS has a very low sensitivity for the detection of VUR, even in children with high grades of VUR. Therefore, other imaging modalities such as VCUG may be necessary to detect VUR.
What is the percentage of children with a history of UTI that exhibit an abnormality on RBUS requiring additional evaluation?
a. 5%–10%
b. 1%–2%
c. 20%–25%
d. 50%–60%
b. 1%–2%.
Explanation: Only 1%–2% of children with a history of UTI exhibit an abnormality on RBUS requiring additional evaluation. However, RBUS is used to follow renal growth in children with a history of UTIs or VUR with kidney size referenced to standard renal growth curves.
FIG. 5.4 Radionuclide cystogram showing right-sided reflux that worsens with bladder filling. The upper collecting system drains fully with voiding.
FIG. 5.5 International classification of vesicoureteral reflux.
What is the preferred method of evaluation for VUR according to many experts, and when is a radionuclide cystogram (RNC) typically used?
a. Preferred method: RNC; used for follow-up imaging: VCUG
b. Preferred method: contrast-enhanced voiding urosonography; used for follow-up imaging: RNC
c. Preferred method: VCUG; used for follow-up imaging: RNC
d. Preferred method: contrast-enhanced voiding urosonography; used for follow-up imaging: VCUG
c. Preferred method: VCUG; used for follow-up imaging: RNC.
Explanation: Many experts prefer to use a contrast VCUG as the initial method of evaluation for VUR because of the improved anatomic resolution, and reserve a radionuclide cystogram (RNC) for follow-up imaging.
When should a VCUG be performed after treating a UTI?
a. Immediately
b. 1 day after treatment
c. At least 1 week after treatment
d. At least 2 weeks after treatment
c. At least 1 week after treatment.
Explanation: The timing of obtaining a VCUG is delayed at least 1 week after treating a UTI to allow for recovery from the infection, but may be performed earlier once the urine is sterile and the child has clinically improved.
What is the gold standard for identification of lesions in the renal parenchyma?
a. Renal ultrasound
b. Voiding cystourethrogram (VCUG)
c. 9mTc-dimercaptosuccinic acid (DMSA) scan
d. Contrast-enhanced voiding urosonography
c. 9mTc-dimercaptosuccinic acid (DMSA) scan.
Explanation: Cortical renal scan with DMSA, especially when combined with single-photon emission computed tomography (SPECT), is the gold standard for identification of lesions in the renal parenchyma.
What does the uptake of DMSA provide a good proportional representation of?
a. VUR
b. Bladder volume
c. Renal function
d. Ureteral dilation
Answer: c. Renal function.
The uptake of DMSA provides a good proportional representation of glomerular filtration and can be used to assess renal function.
What percentage of patients with acute pyelonephritis (APN) have an abnormal DMSA scan within the first 10 days, and how does this change over time?
a. 30%, stays the same
b. 30%, increases over time
c. 49%–79%, decreases over time
d. 49%–79%, stays the same
c. 49%–79%, decreases over time.
Explanation: An abnormal DMSA scan occurs in 49%–79% of patients within the first 10 days of APN, but decreases to 30% after 1 month.
When should assessment of irreversible renal damage and scar be performed after APN?
a. Immediately
b. 1 week after APN
c. 1 month after APN
d. Not earlier than 6 months after APN
d. Not earlier than 6 months after APN.
Explanation: Assessment of irreversible renal damage and scar should not be performed earlier than 6 months after APN.
What can make it difficult to distinguish between acquired postinfection pyelonephritic scars and renal maldevelopment/congenital dysplasia?
a. Interobserver variability
b. Bladder volume
c. Grade of VUR
d. Radiographic appearance
d. Radiographic appearance.
Explanation: VUR, particularly higher grades, is associated with renal maldevelopment/congenital dysplasia that often appears identical to acquired postinfection pyelonephritic scars on radiographic imaging, which can make it difficult to distinguish between the two.
FIG. 5.6 A refluxing ureter with significant dilation of the lower segment but no distortion of the collecting system may be different from the typical system with grade II reflux.
FIG. 5.7 Dimercaptosuccinic acid renal scintigraphy. Pinhole images show a normal left kidney and a right kidney with multiple cortical defects.
Table 5.2
Details of Common Antibiotic Dosing
What are some typical findings associated with renal infection and inflammation on CT imaging?
a. Dilated ureters and bladder
b. Calcifications in the renal parenchyma
c. Cortical regions of hypoattenuation, wedge-shaped defects, loss of corticomedullary differentiation, and striations
d. Multiple renal cysts
c. Cortical regions of hypoattenuation, wedge-shaped defects, loss of corticomedullary differentiation, and striations.
Explanation: Typical findings associated with renal infection and inflammation on CT imaging include cortical regions of hypoattenuation, wedge-shaped defects, loss of corticomedullary differentiation, and striations.
What is the benefit of early antibiotic treatment in pediatric UTI management?
a. It can prevent VUR from developing
b. It can provide detailed anatomic imaging
c. It can prevent renal involvement and subsequent scarring
d. It can eliminate the need for imaging studies
c. It can prevent renal involvement and subsequent scarring.
Explanation: Early antibiotic treatment of febrile UTI can limit renal involvement and subsequent scarring, which is an important goal in pediatric UTI management.
When should antibiotics be started in a child suspected of having a UTI?
a. After imaging studies are performed
b. After the child is confirmed to have a fever
c. Routinely and empirically
d. After the urine culture results are available
c. Routinely and empirically.
Explanation: Antibiotics should be routinely started empirically in a child suspected of having a UTI to prevent delay in treatment and limit the development of renal involvement.
What is the incidence of acute scintigraphic renal lesions when antibiotics are started 2 days after the onset of UTI symptoms?
a. 11%
b. 22%
c. 59%
d. 76.5%
b. 22%.
Explanation: The incidence of acute scintigraphic renal lesions increased in one series from 22%–59% when the start of antibiotics went from 2 to 3 days after the onset of symptoms.
What is the rate of ultimate scar formation when antibiotics are started 6 days after the onset of UTI symptoms?
a. 11%
b. 22%
c. 59%
d. 76.5%
d. 76.5%.
Explanation: The rate of ultimate scar formation also increased from 11%–76.5% when the start of antibiotics went from 2 to 6 days, respectively.
When can infants older than 2 months and nontoxic children with suspected pyelonephritis be treated as outpatients?
a. When there is compliance with and tolerance to oral antibiotics
b. When there is a history of recurrent UTIs
c. When the child has high fever and dehydration
d. When there is suspected VUR
a. When there is compliance with and tolerance to oral antibiotics.
Explanation: Infants older than 2 months and nontoxic children with suspected pyelonephritis can be treated as outpatients if compliance with and tolerance to oral antibiotics is not an issue.
Table 5.3
Commonly Used Prophylactic Antibiotics and Their Dosages
FIG. 5.8 (A) Percent chance of persistence of grades 1, 2, and 4 reflux for 1 to 5 years after initial evaluation. (B) Percent chance of persistence of grade 3 reflux by age for 1 to 5 years after initial evaluation. Source: (Data from Elder JS, Peters CA, Arant BS Jr, et al. Pediatric Vesicoureteral Reflux Guidelines Panel summary report on the management of primary vesicoureteral reflux in children. J Urol 1997;157:1846-1851.)
FIG. 5.9 Robotic extravesical nonrefluxing (tunneled) ureteral reimplantation. A tunnel is made in the detrusor muscle for the ureter, completing the antirefluxing mechanism. (A) After anastomosis of the spatulated ureter to the bladder mucosa, detrusorrhaphy is initiated. (B) Completed extravesical reimplantation. Source: (From Gundeti MS, Kojima Y, Haga N, Kiriluk K. Robotic-assisted laparoscopic reconstructive surgery in the lower urinary tract. Curr Urol Rep 2013;14:333-341.)
FIG. 5.10 Reflux and ureteropelvic junction (UPJ) obstruction. (A) Significant reflux fills the left ureter to the level of the UPJ. Minimal filling of the pelvis can be a sign of obstruction at this level. (B) In a different patient, reflux is seen as the bladder fills. (C) Significant kinking of the UPJ occurs with voiding
FIG. 5.11 Reflux into both ureters of a complete duplication, as shown here, is less common than reflux into the lower pole ureter alone.
Image
FIG. 5.12 (A) Schematic representation of a bladder diverticulum (2). A small amount of mucosa initially herniates through a congenital defect in the bladder musculature. The defect enlarges with voiding. Finally, the ureteric orifice (1) is incorporated into the diverticulum. (B) Reflux into a right-sided paraureteral diverticulum and ureter seen on voiding cystography. Source: (A, From Hernanz-Schulman M, Lebowitz RL. The elusiveness and importance of bladder diverticula in children. Pediatr Radiol 1995;15:399-402.)
