What is the variability between 2 consecutive cystometries in the same child?

PURPOSE: We compared the results of 2 cystometrograms (CMGs) performed during a single session in the same child to determine the variability between consecutive cystometries. MATERIALS AND METHODS: Subjects underwent 2 consecutive bladder fillings performed at the same rate and position. Maximum cystometric bladder capacity (CBC), pressure at CBC, leak point pressure, maximum flow rate, pressure at maximum flow, maximum voiding pressure, residual urine and pressure specific volumes (PSV) less than 20, 30 and 40 cm water were compared between studies. Uninhibited detrusor contractions (UICs), defined by the previous and new International Children's Continence Society definitions of UIC, were also compared. Data were analyzed using paired t test, chi-square and interclass correlation. RESULTS: CMGs in 32 male and 34 female children were available for analysis. Mean subject age was 7.4 years (range 1 month to 18 years). Of the children 43 (65%) had spinal dysraphism, 4 (6%) had cerebral palsy, 5 (8%) had posterior urethral valves, and 14 (21%) had recurrent urinary tract infection, daytime incontinence and frequency/urgency symptoms. Maximum CBC, pressure at CBC, leak point pressure, maximum flow rate, pressure at maximum flow, maximum voiding pressure and residual urine did not differ between the 2 studies. PSVs less than 20, 30 and 40 cm water were highly correlated between the 2 CMGs (interclass correlation coefficients 0.795, 0.683 and 0.850, respectively). There were more UICs on the first than the second study (p = 0.02 and 0.03) as defined by the previous and new definitions of UIC. UIC threshold volume was less on the first CMG (p = 0.00 and 0.03). UICs were either present or absent on both studies in 56 of the 66 (85%) children by the previous UIC definition and in 51 (77%) by the new UIC definition. CONCLUSIONS: There is no difference in CBC, PSV and pressure flow parameters when performing consecutive urodynamic studies in the same child. However, UICs are more frequent on the first study. We conclude that repeat cystometry is not indicated in the absence of UICs on the first study and suggest that the second consecutive CMG be used for clinical interpretation when repeat studies are performed in the same session.

A modified biofeedback program for children with detrusor-sphincter dyssynergia: 5-year experience.

PURPOSE: We reviewed our 5-year experience with a modified 4 to 6-session biofeedback program combining noninvasive urodynamic approaches with various psychological techniques, including externalizing the voiding problem, empowerment and praise, to treat children with detrusor-sphincter dyssynergia. MATERIALS AND METHODS: Biofeedback was performed with a urodynamics processor that enables simultaneous recording of urine flow and electromyography, and visual display of flow/electromyography activity. Initially normal and abnormal voiding were explained in a unique way and the children observed relaxation and contraction of the pelvic floor muscles while visualizing the electromyography monitor. The bladders were filled naturally and surface electrodes were placed. Psychological strategies were used to engage and motivate the children to achieve maximal cooperation. The children voided while attempting relaxation and post-void residual urine volume was measured by bladder scan. Special and specific praise was provided for progress and increasing self-esteem. Patients returned monthly to review these concepts and practice voiding. RESULTS: Of 87 children 77 completed the program, including 7 boys and 70 girls 3 to 17 years old (mean age 7.8) who required an average of 4.7 sessions (median 4). Results were achieved within 6 sessions in 82% of cases. Of the 77 children 59 (76%) had recurrent urinary tract infections, 38 (49%) had associated bladder instability, 19 (24%) had vesicoureteral reflux and 44 (58%) had constipation. Subjectively 47 patients (61%) reported pronounced improvement in urinary symptoms, while another 24 (32%) reported moderate improvement after biofeedback training. Objectively 47 children (61%) had normal flow with minimal electromyography activity during voiding and a normal post-void residual urine of less than 20% voided volume (p <0.002). In 28 cases (36%) flow studies improved (p <0.03) but post-void residual urine remained elevated. Vesicoureteral reflux resolved in 9 cases after biofeedback training. This approach was equally successful in children in all age groups. Those with more than a 2-year history of symptoms, poor bladder emptying and severe constipation had only moderate improvement. CONCLUSIONS: The modified biofeedback program including appropriate explanations and psychological approaches appeared effective for treating 92% of children with detrusor-sphincter dyssynergia. It is less invasive and requires less time than traditional methods, and patients are more compliant with treatment.