Traces: making sense of urodynamics testing--Part 8: Evaluating sensations of bladder filling

The "Traces" series discusses how the urodynamic clinician generates usable data from a filling cystometrogram (CMG). Part 8 focuses on the question, "What are the sensations of bladder filling?" Recent research suggests that sensations of bladder filling wax and wane from consciousness in healthy persons free of bothersome lower urinary tract symptoms. Because of its invasive and atypical nature when compared to daily life, multichannel urodynamics testing cannot reproduce the numerous and complex variables that influence bladder sensation in the healthy individual, making the evaluation of sensations of bladder filling a particularly challenging component of the filling CMG. Routine assessment of bladder sensations focuses on identification of three landmarks--first sensation of bladder filling, first desire to void, and a strong desire to void. A fourth sensation, bladder fullness or a compelling desire to void, is recommended. In addition to assessing these sensations, the urodynamic clinician must assess sensations indicating associated disease or disorders affecting lower urinary tract function, including urgency, pain, and atypical sensations. This assessment should be completed in the context of the results of one or more validated instruments used to measure bladder sensations.