Typical value ranges and typical signal patterns in the initial cough in patients with neurogenic bladder: Quality control in urodynamic studies

Abstract

Purpose: The goal of this study was to establish typical value ranges (TVRs) and to analyze typical signal patterns (TSPs) of the initial cough (cough before bladder filling) for quality control in urodynamic studies. Methods: A total of 539 urodynamic traces from patients with neurogenic bladder obtained over the course of a year were retrospectively reviewed. The TVRs for cough amplitude in measurements of the intravesical pressure (Pves), abdominal pressure (Pabd), and detrusor pressure (Pdet) during the initial cough were established. We used the 95% range as a reference range for all parameters. Cough spikes in Pdet were described and classified, and the reasons for different patterns of cough spikes were established. The quality of all the cystometry traces was checked, and we also present remedial actions for inappropriate cough spikes. Results: The cough amplitudes in the measurements of Pves and Pabd were similar, with 95% of measurements falling within the following ranges: 4-62 cm H2O and 3-70 cm H2O, respectively, in supine position and 9-95 cm H2O and 8-98 cm H2O, respectively, in sitting position. For Pdet, the cough amplitude ranged from -38 to 25 cm H2O in supine position and from -44 to 41 cm H2O in sitting position. The cough spikes for Pdet were classified as follows: type I, Pdet pressure exhibited a minimal change ( < 5 cm H2O) during the cough; type II, a monophasic spike ( > 5 cm H2O) was observed for Pdet; and type III, biphasic spikes were observed for Pdet. Type I coughs were found to have more high-quality traces (P < 0.01). Conclusions: TVRs for the initial cough test among neurogenic patients were established in order to provide guidelines for quantitative quality control. The TSPs for the initial cough signal were described, and the presence of a high-quality cough signal may be recommended as a component of quality control in urodynamic measurements.