Correspondence  |   November 2018
In Reply
Author Notes
  • Department of Anaesthesiology and Pain Medicine, Bern University Hospital, Inselspital, University of Bern, Bern, Switzerland (P.Y.W.).
  • (Accepted for publication July 30, 2018.)
    (Accepted for publication July 30, 2018.)×
Article Information
Correspondence   |   November 2018
In Reply
Anesthesiology 11 2018, Vol.129, 1048-1049. doi:10.1097/ALN.0000000000002419
Anesthesiology 11 2018, Vol.129, 1048-1049. doi:10.1097/ALN.0000000000002419
We thank Dr. Kendall for his repeated interest in our investigations and his valuable comments.
Dr. Kendall’s first concern was our choice of primary outcome (i.e., differences in postvoid residual urine volume rather than the need for bladder catheterization), arguing that the need for bladder catheterization is related to poor outcome.1  Indeed, bladder catheterization is linked with urinary tract infections and patient discomfort.2  We chose a change in postvoid residual because elevated postvoid residuals are a common reason for bladder catheterization. Therefore, postvoid residual is not only a surrogate of voiding dysfunction, but also directly linked to poor outcomes. Our study was underpowered to assess significance in the rate of urinary tract infections, but this was not the focus of our study. Changes in postvoid residual, however, are a very sensitive value for lower urinary tract function in general and an acknowledged sign of its dysfunction, which was the target of assessment in this randomized clinical trial. The International Consultation on Benign Prostatic Hyperplasia defines a postvoid residual of 50 to 100 ml as abnormal.3  Based on precedent observations4  the primary endpoint, change in postvoid residual, indicates a relevant change in lower urinary tract function.