Assessment of quality in urodynamics: Cough versus valsalva

To ensure quality, the International Continence Society recommends asking the patient to cough every minute or 50 ml of infused volume. However, on occasions, it was noticed that if cough transmission was poor, Valsalva maneuvers could show pressure transmission was satisfactory. Hence, a study was designed to compare the two methods.

Cough and Valsalva maneuver pressures were compared in 40 patients, 20 consecutive men and 20 consecutive women, undergoing urodynamics at three time points: baseline (20 ml filling), prevoid and postvoid.

At baseline, the percentage difference between p_abd and p_ves was significantly lower for Valsalva maneuvres compared with coughs for all patients (median 5.1% vs. 10.2%). This association was consistent in male patients, but not for female. At prevoid, this was reversed with coughs providing more consistent pressure spikes than Valsalva maneuvers (median 7.0% vs. 24.1%), for all patients. Postvoid, no difference was noted in either men or women.

Quality control during urodynamics is important to ensure diagnostic accuracy. This is the first study to compare two methods of quality control, coughs, and Valsalva maneuvers. Coughs are a useful indicator of pressure transmission quality at all time points throughout urodynamic studies. However, at low volumes, Valsalva maneuvers give a better indication of quality, with lower variability, whereas at cystometric capacity coughs performed better. Therefore, if poor pressure transmission occurs with cough during urodynamics, particularly at low volumes, it is recommended that a Valsalva maneuver is used to further assess whether pressure transmission and thus urodynamic quality is satisfactory.