Limitations of urinary pH monitoring in long-term catheter users.

Weekly measurement of urinary pH has become a standard part of long-term catheter management in many parts of the UK. The common problem of catheter encrustation is caused by urease-producing bacteria which also tend to produce alkaline urine. To determine if urinary pH changes in individual catheter users provided enough information for pH monitoring to aid in catheter management, an analysis of the literature was combined with a study of the urinary pH and catheter blockage patterns in 20 catheter users colonized with urease-producing bacteria. It was found that weekly pH measurement does not aid in the diagnosis or management of catheter encrustation. As such, this practice cannot be recommended.