[Urodynamics: All the nurse needs to know].

Urodynamic (UD) is an exam intended to explore the mechanisms underlying lower urinary tract symptoms (LUTS) or urinary incontinence (UI). It involves the measurement of bladder and sphincter pressures using uretrovesical and rectal catheters with pressure transducers, but also the measurement of urinary flow and bladder sensation during filling. UD is far from being systematic in the assessment of LUTS or UI and must seek to tackle a specific clinical or therapeutic question. Thus, history taking, physical examination, voiding diary and questionnaires are essential prerequisites to UD per se. UD steps include a free (unintubated) uroflowmetry, a cystometry, post-void residual measurement±an urethral profilometry, a pressure-flow study or sensitization tests. The pressures are set to zero before to start the study and the validity of the equipment is tested. This control is continued throughout the procedure to ensure the quality of the recording. Any event (e.g., urine leakage, change of position, urgency) is noted during the study. A final report is made by the doctor. The competence of the nurse ensures the reliability, reproducibility and interpretability of the UD study and the nurse's humanity guarantee f an atmosphere as favourable as possible for this uncomfortable and invasive test.