What is the appropriate emergency management and diagnostic work‑up for a 1.5‑year‑old child presenting with acute urinary retention?

Emergency Management of Acute Urinary Retention in an 18-Month-Old Child

Immediately catheterize the bladder (urethral or suprapubic) to relieve the obstruction, then urgently investigate for structural anomalies, neurologic causes, or infection—acute urinary retention in toddlers is rare and almost always signals serious underlying pathology requiring prompt diagnosis and specialist referral.

Immediate Bladder Decompression

• Insert a urethral catheter as the first-line intervention to decompress the bladder and relieve pain; suprapubic catheterization is an alternative if urethral catheterization fails or is contraindicated 1, 2, 3.
• Measure the post-void residual volume at catheterization to document the degree of retention 2.
• Send the catheterized urine specimen immediately for urinalysis and culture before any antibiotics are given 4, 5.

Urgent Diagnostic Work-Up

Clinical Assessment Priorities

• Document the duration of symptoms, any preceding trauma, recent illness, fever, or change in bowel habits (constipation is a common contributor in toddlers) 3.
• Perform a focused neurologic examination including lower extremity strength, tone, reflexes, and perineal sensation to detect spinal cord pathology 2, 3.
• Examine the abdomen for a palpable bladder mass, suprapubic tenderness, or fecal impaction, and inspect the external genitalia for anatomic abnormalities, trauma, or signs of infection 4, 6.
• Check for signs of sepsis or systemic illness (fever, irritability, poor feeding, lethargy) that may indicate urosepsis or neurologic emergency 7, 4.

Laboratory Evaluation

• Obtain urinalysis and urine culture from the catheterized specimen to rule out urinary tract infection, which can cause retention in young children 4, 5.
• Check serum creatinine and electrolytes if there is concern for obstructive uropathy or renal impairment 4, 6.

Imaging Studies

• Order renal and bladder ultrasound emergently (within hours, not days) to detect hydronephrosis, posterior urethral valves, ureterocele, bladder mass, or other structural abnormalities 7.
• Consider spinal ultrasound or MRI if neurologic examination is abnormal or if there are cutaneous stigmata of occult spinal dysraphism (sacral dimple, tuft of hair, nevus) 3.
• Do not delay imaging while waiting for urine culture results—structural causes require immediate identification 6.

Etiologic Categories in Toddlers

• Structural causes (posterior urethral valves, urethral stricture, ectopic ureterocele, bladder neck obstruction) are the most common in this age group and require urgent urologic consultation 8, 2, 3.
• Neurologic causes (spinal cord compression, tethered cord, sacral agenesis, transverse myelitis) must be ruled out with neurologic examination and imaging if indicated 2, 3.
• Infectious/inflammatory causes (severe cystitis, vulvovaginitis causing reflex retention, sacral herpes) should be considered if fever or genital lesions are present 8, 3.
• Functional/behavioral causes (severe constipation with fecal impaction, voluntary withholding) are diagnoses of exclusion after structural and neurologic pathology are ruled out 6, 3.

Specialist Consultation and Disposition

• Consult pediatric urology urgently (same day) for all cases of acute urinary retention in toddlers, as most will require cystoscopy, voiding cystourethrography (VCUG), or surgical intervention 7, 3.
• Admit the child for observation and further work-up if the cause is not immediately apparent, if there is concern for neurologic pathology, or if the child appears systemically ill 2, 3.
• Arrange VCUG after initial stabilization (typically within 24–48 hours) if ultrasound shows hydronephrosis or if posterior urethral valves are suspected 7.

Critical Pitfalls to Avoid

• Do not assume constipation is the sole cause without imaging—structural anomalies (especially posterior urethral valves in boys) are common and require urgent diagnosis 6, 3.
• Do not discharge the child home with an indwelling catheter without a clear diagnosis and specialist follow-up arranged—prolonged catheterization increases infection risk and delays definitive treatment 1, 9.
• Do not miss spinal cord pathology by failing to perform a thorough neurologic examination and obtain spinal imaging when indicated 2, 3.
• Do not delay catheterization to obtain imaging first—bladder decompression is the immediate priority to prevent bladder injury and relieve pain 1, 2.