Rickwood AM, Harney W, Jones MO, Oak S.

'Congenital' hydronephrosis: limitations of diagnosis by fetal ultrasonography. BrJ Urol 1995; 75: 529-530.

21. Rickwood AM, Jee LD, Williams MP, Anderson PA.

Natural history of obstructed and pseudo-obstructed megaureters detected by prenatal ultrasonography. BrJ Urol 1992; 70: 522-525.

Ringert RH, Kallerhoff M.

Leitlinie zur Diagnostik der Harntransportstorungen in der Kinderurologie. Urologe A 1998; 37: 573-574.

Roarke MC, Sandier CM.

Provocative imaging. Diuretic renography. Urol Clin North Am 1998; 25: 227-249.

Ward AM, Kay R, Ross JH.

Ureteropelvic junction obstruction in children. Unique considerations for open operative intervention. Urol Clin North Am 1998; 25: 211-217.

Wilcox D, Mouriquand P.

Management of megaureter in children. Eur Urol 1998; 34: 73-78.

URINARY TRACT INFECTION (UTI)

CLASSIFICATION

Asymptomatic bacterium

Significant bacteriuria can be documented in consecutive urine samples without any symptoms.

Cystitis

The infection is limited to the bladder; irritative symptoms are present, but no systemic symptoms or fever.

Acute pyelonephritis

Febrile infection of the renal parenchyma.

Complicated UTI

Due to a urine transport disturbance, malformation or a relevant bladder voiding disturbance.

DIAGNOSIS

Indications for chemical and microbiological urine examination include fever of unknown origin, unclear growth impairment in infants, unclear abdominal complaints or flank pain, frequency, dysuria, smelly urine and gross haematuria. In infants and small children, urine is usually collected in a bag attached to the external genitalia. A positive urine culture requires confirmation by suprapubic puncture (withdrawal of urine by transurethral catheterization is optional). Once the child can void on demand, mid-stream urine is used in boys and transurethral catheterization in girls.

The urine examination consists of paper-strip tests, microscopy and microbiology. Only the examination of bladder puncture urine achieves a sensitivity of > 95%. In cases of a positive urine culture, complete blood count, differential blood count, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are determined together with clinical examination.

Sonography is performed to assess kidney volume, parenchymal echogenicity, thickness and scarring, anomalies (e.g. duplex system), hydronephrosis, dilatation of the ureter and calculi. Bladder wall thickness, bladder configuration, dilatation of the ureter (VCUG, to rule out reflux) and residual urine are assessed with a full bladder. In case of pyelocaliectasis, an IVU should be considered. A VCUG should be carried out after successful antibiotic therapy.

Table 7: Differential diagnosis of pyelonephritis

 

	Pyelonephritis likely	Pyelonephritis unlikely
ESR	> 25 mm n. W	< 25 mm n. W
CRP	> 1 mg/mL	< 1 mg/mL
Body temp.	> 38.5 °C	> 38.5 °C
Leucocytosis/left shift	Present	Not present
Leucocyte casts in urine	Evidence	No evidence
Kidney volume	Enlarged	Not enlarged

ESR = erythrocyte sedimentation rate; CRP = C-reactive protein

TREATMENT

Asymptomatic bacteriuria

No treatment is required in children with a normal urinary tract; functional voiding disturbances should be excluded.

Acute UTI without pyelonephritis

Trimethoprim/sulphamethoxazole, trimethoprim (mono-), oral cephalosporins or amoxycillin (third choice) is given for 3-5 days.

Pyelonephritis

Intravenous antibiotic therapy with a broad-spectrum penicillin or cephalosporin is started immediately. In case of non-sensitive bacteria, a reserve antibiotic agent is chosen. In newborns, treatment should last for 14-21 days. The therapy is then continued orally for 7-14 days. In impaired renal function, the dosage is adjusted according to the serum creatinine level. Therapy can be stopped when urine culture is sterile and all signs of inflammation have disappeared. DMSA scintigraphy may be performed 3 months after the end of treatment. In obstructive pyelonephritis, urinary drainage should be considered as an emergency.

Complicated UTI

Efficient management of complicated UTIs requires appropriate treatment of the underlying condition (e.g. impaired urinary drainage).

Antibiotic prophylaxis

Nitrofurantoin and trimethoprim are currently considered as first-line treatment; alternatives are amoxycillin or cephalosporins. Long-term antibiotic prophylaxis is required particularly in children with VRR. Other indications for antibiotic prophylaxis are recurrent cystitis with or without voiding disturbances, medullary sponge kidneys, kidney duplication with reflux to the lower pole, ectopic ureters, dilatation of the upper urinary tract, ureterocele and neurogenic bladder dysfunction (e.g. MMC or tethered chord syndrome).

REFERENCES

Ahmed SM, Swedlund SK.

Evaluation and treatment of urinary tract infections in children. Am Fam Physician 1998; 57: 1573-1580, 1583-1584.

Alon US, Ganapathy S.

Should renal ultrasonography be done routinely in children with first urinary tract infection? Clin Pediatr Phil 1999; 38: 21-25.

Auringer ST.

Pediatric uroradiology update. Urol Clin North Am 1997; 24: 673-681.

Bitar CN, Steele RW.

Use of prophylactic antibiotics in children. Adv Pediatr Infect Dis 1995; 10: 227-262.