[Fluid loss pressure in 45 children with congenital neurogenic bladder].

OBJECTIVE

This study analyzed the relation between leak point pressure (LPP) at first urodynamic evaluation and the status of the upper urinary tract (UUT) and renal reflux (RR).

METHODS

The study comprised 45 myelodysplastic children, one week to 13 years of age; 19 (42%) were less than one year old. LPP was measured when liquid started to come out through the urethral meatus, around the 5-6 Fr catheter. UUT was evaluated by ultrasound and RR by voiding cystography.

RESULTS

19 children had LPP < 30 cm H2O; all cases had a normal UUT, although 5 (26%) had RR. Twenty-six cases (58%) had LPP > 30 cm H2O; 12 (46%) had abnormal UUT and 6 of these had RR; 7 cases had RR but normal UUT. The group with LPP > or = 30 cm H2O was analyzed according to LPP values. The UUT was abnormal in 31% of cases with LPP 30-60 cm H2O and 37% had RR; UUT was abnormal in 70% of cases with LPP > 60 cm H2O and 70% had RR. Of the 19 patients less than one year old 9 (47%) had LPP < 30 cm H2O, no patient had abnormal UUT and only two (22%) had RR; 10 cases had LPP > or = 30 cm H2O, 6 of these had abnormal UUT and 5 had RR.

CONCLUSIONS

In this study UUT was normal when LPP was < 30 cm H2O. Renal impairment and RR increased with LPP. Urethral functional obstruction carries a worse prognosis of pediatric neurogenic bladder. In these cases clean intermittent catheterization is recommended, regardless of patient age and sex.