The data from five trials comparing differing washout policies were sparse and trials were generally of poor quality or poorly reported. The evidence was too scanty to conclude whether or not washouts were beneficial. In the first instance we require further rigorous, high quality trials with adequate power to detect any benefit from washout being performed as opposed to none. Then trials comparing different washout solutions, washout volumes, frequencies/timings and routes of administration are needed.
Evaluation of 3 methods of bladder irrigation to treat bacteriuria in persons with neurogenic bladder.
We conducted a randomized, double-blind comparison of twice daily bladder irrigation using 1 of 3 different solutions in community-residing persons with neurogenic bladder who used indwelling catheters to evaluate efficacy in treatment of bacteriuria.
                Eighty-nine persons with bacteriuria were randomized to irrigate their bladders twice daily for 8 weeks with 30 mL of (a) sterile saline, (b) acetic acid, or (c) neomycin-polymyxin solution. Urinalysis, cultures, and antimicrobial susceptibility tests were performed at baseline and weeks 2, 4, and 8 to determine the extent to which each of the solutions affected numbers and types of bacteria, urinary pH, urinary leukocytes, and generation of antimicrobial-resistant organisms.
                Bladder irrigation was well tolerated with the exception of 3 participants who had bladder spasms. None of the 3 irrigants had a detectable effect on the degree of bacteriuria or pyuria in 52 persons who completed the study protocol. A significant increase in urinary pH occurred in all 3 groups. No significant development of resistance to oral antimicrobials beyond what was observed at baseline was detected.
                Bladder irrigation was generally well tolerated for 8 weeks. No advantages were detected for neomycin-polymyxin or acetic acid over saline in terms of reducing the urinary bacterial load and inflammation. We cannot recommend bladder irrigation as a means of treatment for bacteriuria in persons with neurogenic bladder.