A quantitative approach to the interpretation of uroflowmetry in children

Abstract

Our predictive formulas allow for direct comparison of one flow to the next in a single patient when the FI is used. Utilizing the FI, we can predict the type of flow pattern removing subjectivity from the analysis of uroflow patterns. Neurourol. Urodynam. 35:836-846, 2016. © 2015 Wiley Periodicals, Inc.

The relationship among flow index, uroflowmetry curve shape, and EMG lag time in children

“…On the basis of this digitized voiding efficiency, a strong correlation has been demonstrated between Fl and the shape of flow curve in normal voiders and children with LUTs. 3,9 In other words, higher FI is associated with a tower-shaped curve, while lower FI is associated with a plateau-shaped curve. EMG can be used for diagnosing specific conditions of LUTs by appreciating synergy or dyssynergy between the bladder and pelvic floor.…”

“…Recently, Franco et al 9 published the concept of flow index (FI) to provide a quantitative assessment of voiding efficiency by modifying the existing method. Higher FI indicates efficient voiding and a tower‐shaped UF curve, while lower FI indicates inefficient voiding and a plateau‐shaped UF curve.…”

Lower Urinary Tract Dysfunction and Associated Pons Volume in Patients with Wolfram Syndrome

“…Interpretation of urodynamic testing is also subject to inter-and intraobserver variation, although using calculated flow index to help normalize uroflometry data eliminates a great deal of interpretation subjectivity. 22 We did not ascertain presence of upper tract dilation or relation to degree of diabetes insipidus or polyuria. Past reports have noted poor correlation between diabetes insipidus and hydronephrosis.…”

“…Both quantitative and qualitative measures were recorded, including average flow, maximum flow, voided volume, curve shape (bell-shaped, tower, plateau, staccato, intermittent or other). A flow index was calculated for each patient using equations derived by Franco et al 22 Each test was categorized as either normal or disordered if voided volume was ≥ 50 mL. A disordered uroflow corresponded to flow indices < 0.7 for males and < 0.68 for females.…”

Can the idealized voider derived flow indexes be a measure of voiding efficiency and how accurate are they?

“…Once the patient has an elevated postvoid residual, the concept of the uroflow being an accurate measure of the flow dynamics is thrown off by the fundamental property that flow rates are directly proportional to the total volume of urine in the bladder. Our most recent publication where we have developed an idealized voider flow equation (IVFE) to calculate Qmax and Qavg and then converting the Actual Q/Estimated Q into a flow index, normalizes for the total bladder volume at the time of the void and thereby corrects for the aforementioned flaw in uroflowmetry interpretation. In the adult literature a study using a flow index based on total bladder volume substantiates our premise that formulas based off total bladder volume are a better method to separate out dysfunctional voiders …”