Fig. 1.
(A) Example of a representative urodynamic tracing from a study patient showing one micturition at baseline. An electromyography (EMG) shows tracing taken from the pelvic floor muscles by perianal surface electrodes. (B) A representative urodynamic tracing from a study patient showing one micturition cycle during thoracic epidural analgesia postoperatively with urinary retention due to detrusor muscle underactivity. Flow = voided urine measured on the scale over time; Pabd = intraabdominal pressure (measured by the rectal balloon); Pdet = detrusor pressure (calculated as difference from Pves – Pabd); PdetQmax = detrusor pressure at maximum flow rate; Pves = intravesical pressure; Qmax = maximum flow rate; Vinf = filling of the bladder.