Urinary tract infection (pediatrics): Clinical sciences

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Introduction0:00–0:48

Urinary tract infection, or UTI for short, is a common bacterial infection in children that can involve any part of the urinary tract.
In children, UTIs are usually caused by gastrointestinal flora, such as Escherichia coli, that ascend into the bladder or kidneys, causing cystitis, pyelonephritis, or even urosepsis.
If not treated promptly, UTIs can result in long-term complications, such as renal scarring, hypertension, and chronic renal disease.
The management of UTIs depends on the patient’s age; more specifically, whether they are less or more than 2 months old.If a child presents with a chief concern suggesting a UTI, you should first perform an ABCDE assessment to determine whether the child is stable or unstable.

Unstable patients0:48–1:28

If your patient is unstable, stabilize the airway, breathing, and circulation. Next, obtain IV access, administer IV fluids, and start broad-spectrum antibiotics.
Finally, begin continuous vital sign monitoring, including blood pressure, heart rate, respiratory rate, and oxygen saturation.
If needed, don’t forget to provide supplemental oxygen. Okay, now let’s go back to the ABCDE assessment and take a look at stable patients.

Stable patients1:28–1:45

In this case, start by obtaining a focused history and physical exam. Next, assess the patient's age, which will guide the treatment!First, let’s take a look at term infants of 2 months of age and younger.

< 2 months1:45–2:22

These patients typically present with vague systemic symptoms, like fever, fussiness, and lethargy. Additionally, caretakers may report poor oral intake or vomiting, and they may describe the baby’s urine as foul-smelling.
Next, the physical exam typically reveals an ill-appearing, uncomfortable infant with a body temperature of 38 degrees Celsius or higher.
The physical exam could also reveal tachycardia and suprapubic tenderness. Based on these findings, you should suspect a UTI, so your next step is to order labs, which include CBC, CRP, procalcitonin, and urinalysis, as well as urine and blood cultures.

Labs2:22–3:28

Your work-up for this age group may also include a cerebrospinal fluid analysis and culture as part of a sepsis evaluation.
Now here’s a clinical pearl to keep in mind! You can collect a urine sample from an infant by bag collection, bladder catheterization, or suprapubic bladder aspiration.
Because urine collected by a bag specimen is often contaminated with skin flora, it should only be sent for a urinalysis and not for culture.
For this reason, bladder catheterization is the most common method used in this age group to collect a urine sample for culture.
On the other hand, suprapubic needle aspiration is a painful procedure that’s not commonly used due to a relatively low success rate!Next, admit your patient to the hospital and start empiric antibiotics, which include ampicillin, and either gentamicin or cefotaxime for coverage of gram-negative bacteria.

Initial management3:28–3:51

Additionally, don’t forget to provide adequate hydration with IV fluids and administer antipyretics, such as acetaminophen, for fever.Now let’s take a look at lab results!

Lab results3:51–4:43

CBC will typically reveal elevated white blood cell count, and inflammatory markers will be elevated. Additionally, urinalysis often shows the presence of white blood cells and positive leukocyte esterase, indicating an inflammatory response that is suggestive but not diagnostic of a UTI.
A urine culture with bacterial growth of over 50,000 colony-forming units per milliliter from a catheterized urine specimen confirms UTI; but for neonates and children with immune deficiency, growth of as few as 10,000 colony-forming units per milliliter suggests infection.
Finally, positive bacterial growth from the blood culture is concerning for urosepsis. At this point you can be sure that your patient has a UTI, so tailor antibiotics based on culture results.

Management4:43–5:28

Continue supportive care with adequate hydration and antipyretics as needed. Finally, once the UTI resolves, all infants under 2 months of age with UTI should have a renal and bladder ultrasound.
If the ultrasound reveals a urinary tract abnormality, such as a ureterocele or posterior urethral valves, order a voiding cystourethrogram, or VCUG for short, to assess for vesicoureteral reflux, bladder or urethral dysfunction, and structural abnormalities.
Okay, now let’s go back and discuss how to evaluate and manage children older than 2 months. In this case, caretakers usually report fever, irritability, or decreased activity, while a verbal child may describe dysuria, urgency, and frequent urination.

Stable patients > 2 months5:28–6:33

Additionally, caretakers might also report poor oral intake, vomiting, or foul-smelling urine. Other important historical findings include problems with toilet training, constipation, or recurrent UTIs.
There could also be additional risk factors such as patients who are biologically female or biological males who are uncircumcised.
The physical exam typically reveals an ill-appearing, uncomfortable child with a body temperature of 38 degrees Celsius or higher, with or without tachycardia.
Additionally, you might notice suprapubic tenderness, which is a sign of bladder involvement; or costovertebral angle tenderness, which occurs if the infection reaches the kidneys.
At this point, you should suspect UTI, so make sure to order labs, including a CBC, CRP, procalcitonin, urinalysis and urine culture, as well as blood culture, if needed.

Labs6:33–7:20

Older, toilet-trained children may be able to provide a urine specimen using a clean-catch method, which avoids the need to perform bladder catheterization.
Next, assess whether you need to admit your patient or if you can proceed with outpatient management. Admission criteria for a child with UTI are based on a number of factors, including illness severity, likelihood of pyelonephritis or urosepsis, the presence of other comorbidities, and inability to take oral fluids and medications.If your patient doesn’t meet admission criteria, proceed with outpatient medical management, starting with empiric oral antibiotics, such as a first-generation cephalosporin, trimethoprim-sulfamethoxazole, or nitrofurantoin.

Outpatient management & labs7:20–8:16

Additionally, counsel caregivers on proper hydration and the use of antipyretics. Now, let’s take a look at the lab results.
CBC might reveal elevated white blood cell count, and inflammatory markers might be elevated. Urinalysis often reveals the presence of white blood cells with positive leukocyte esterase, both of which indicate an inflammatory response.
As for the urine culture, bacterial growth of over 50,000 colony-forming units per milliliter from a catheterized urine specimen, or over 100,000 colony-forming units per milliliter from a clean-catch specimen, confirms urinary tract infection.
Based on these lab findings, you can diagnose a simple UTI! In this case, tailor antibiotics based on culture results and advise caregivers to continue adequate hydration and antipyretics when needed.

Simple UTI8:16–8:59

Finally, If your patient is less than 2 years of age with a febrile UTI, or if they have a history of recurrent UTIs, order a renal and bladder ultrasound.
If the ultrasound reveals hydronephrosis or another abnormality, proceed with VCUG to assess for vesicoureteral reflux, bladder or urethral dysfunction, and structural abnormalities.
Now, let’s go back and take a look at what to do if the patient meets the admission criteria. In this case, proceed with empiric intravenous antibiotics, such as a third-generation cephalosporin like cefotaxime, keeping in mind local bacterial resistance patterns.

Inpatient management & labs8:59–10:03

Ensure that your patient is receiving adequate hydration, especially if oral intake is not optimal, and provide antipyretics as needed for fever.
Labs typically reveal elevated white blood cell count and elevated inflammatory markers. Urinalysis typically shows white blood cells with positive leukocyte esterase, both of which indicate an inflammatory response.
As for the urine culture, bacterial growth of over 50,000 colony-forming units per milliliter from a catheterized urine specimen, or over 100,000 colony-forming units per milliliter from a clean-catch specimen, confirms urinary tract infection.
Finally, in these individuals, blood cultures can come back positive, which indicates urosepsis!At this point you can diagnose complicated UTI, so make sure to tailor antibiotics based on culture results.

Complicated UTI10:03–11:06

Continue supportive care and don’t forget to schedule renal and bladder ultrasound or VCUG, if needed!Now here’s a clinical pearl to keep in mind!
Some children with recurrent UTIs or an increased risk of renal scarring may benefit from prophylactic antibiotic treatment.
For example, neonates with detectable hydronephrosis on prenatal ultrasound who are subsequently found to have high-grade vesicoureteral reflux on VCUG should be given prophylactic antibiotics to lower the risk of a first febrile UTI.
Other children with functional or anatomic abnormalities of the urinary tract might be candidates for antibiotic prophylaxis, though the risk of antibiotic resistance with long-term use must always be weighed against any potential benefits.Alright, as a quick recap… If a child presents with symptoms suggestive of UTI, perform a history and physical exam and order labs.

Review11:06–12:25

For children 2 months and younger, order CBC, CRP, procalcitonin, urinalysis, as well as urine and blood cultures; and possibly CSF analysis and culture as part of a sepsis evaluation.
A positive urine culture confirms the diagnosis of UTI, so hospitalize your patient and begin IV antibiotics and antipyretics.
On the flip side, management of children over 2 months depends on admission criteria, including illness severity, likelihood of pyelonephritis or urosepsis, presence of other comorbidities, and inability to tolerate oral intake.
If admission criteria aren’t met, start with empiric oral antibiotics and supportive care. On the other hand, if the child meets the criteria for hospitalization, start empiric IV antibiotics and supportive care.
Finally, if renal or bladder ultrasound reveals a urinary tract abnormality, obtain VCUG to assess for vesicoureteral reflux, bladder or urethral dysfunction, and structural abnormalities.