EAU 2018: Pain Tolerance During Treatment of Urinary Stones with ESWL: Factors of Influence

Copenhagen, Denmark (UroToday.com) Dr. Bongers, a clinical urologist from The Chinese University of Hong Kong, SH Ho Urology Centre, Hong Kong, Hong Kong, presented a study that analyzed the contributing factors to pain tolerance during treatment of urinary stones with Extracorporeal Shock Wave Lithotripsy (ESWL). Pain has often been associated with ESWL, despite the use of analgesics; therefore determinations of influential factors can have a large impact on proper management of pain.

In this study, treatment characteristics during ESWL on 860 patients were evaluated. To begin, 100mg of diclofenac suppository was prescribed to each patient before undergoing ESWL. Afterwards, pain tolerance to ESWL was measured through an increase of shock waves from 1 to 9 until ‘tolerated energy level’, defined as the maximum energy level used for majority (>50%) of treatment, was reached. This value was recorded and a linear mixed model was used to analyze correlations between pain tolerance and a number of multiple variables. Of those variables, gender, stone location, and shock interval were found to be significant contributors to pain tolerance.

Furthermore, age and time since last maintenance of lithotripter was shown to have a quadratic effect on ability to tolerate pain. As age increased, pain tolerance generally increased until an apex was reached at around 70 years of age, where a decline was noticed as age progressed. Tolerated energy also increased in the first 10 months since maintenance, after which the tolerated energy decreased. This indicates decreasing shockwave energy as time progressed.

In conclusion, Dr. Bongers reiterated that a number of factors are shown to have a significant influence on pain tolerance during ESWL and can potentially affect the effectiveness of SWL treatment.

Speaker: Dr. Bongers

Authors: Bongers M., Böing-Messing F., Van Roijen H.

Written by: Whitney Zhang, Department of Urology, University of California-Irvine, at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark