Good hygiene practices are imperitive to UTI prevention. Therefore, it is a natural extension to expect that antiseptic agents applied either directly to the bladder or to potential vectors of indirect transference might be effective in UTI prevention. Accordingly, Sanderson and Weissler (1990a) found that perineal colonization of SCI individuals was significantly correlated with bacteriuria and may be associated with contamination of the environment and indirectly of the hands of patients and staff. As a result of this finding, this group further examined the effect of chlorhexidine antisepsis on bacteriuria, perineal colonization and environmental contamination in spinally injured patients requiring intermittent catheterization (Sanderson & Weissler 1990b). In male patients not receiving antibiotics, daily body washing in chlorhexidine and application of chlorhexidine cream to the penis after every catheterization significantly reduced bacteriuria to 60% from 74% in patients who only washed with standard soap; however, the effect was not as strong as that delivered by treatment with appropriate antibiotics. Chlorhexidine antisepsis alone did not affect perineal coliform colonization or contamination of the environment although there was a trend for this effect (p<0.1). In essence, this antiseptic effect acted to amplify the bacteria-reducing effects of antibiotics.
Acidifying urinary pH for the prevention of UTIs is based on the established fact that pH reduction to ≤5.0 will inhibit growth of urinary E. coli (Shohl & Janney 1917), a prevalent pathogen in the urinary tract. An RCT conducted by Waites et al. (2006) on individuals with indwelling or SPC with existing bacteriuria and pyuria (n=89) the effects of sterile saline, acetic acid and neomycin-polymyxin solution bladder irrigants on the degree of bacteriuria/pyuria, or development of antimicrobial resistance; the authors found no significant difference between groups. Moreover, the twice daily bladder irrigation for 8 weeks resulted in a significant increase in urinary pH (p=0.01) for all groups to a range that was more favourable for the growth of E. coli (i.e., pH 6.0-7.0). Similarly, 2 weeks of phosphate supplementation (Schlager et al. 2005) or 2 g daily ascorbic acid (Castello et al. 1996) for unspecified duration in SCI neurogenic bladder managed with IC or indwelling catheter have proved ineffective in acidifying urine or altering UTI rates.
Feasibility of treatment is a valid issue for consideration as evidenced by the study conducted by Pearman et al. (1988). These investigators compared the use of trisdine with kanamycin-colistin, a medicated bladder instillation previously demonstrated to be effective to prevent bacteriuria and UTI in SCI (Pearman 1979). In this trial (n=18), they found no difference between incidence of bacteriuria in catheterized patients yet concluded that trisdine was preferred based on its stability at room temperature, association with a reduced likelihood for antibiotic-resistant bacteria and reduced cost compared to kanamycin-colistin. Although the latter are important factors for treatment choice, this study presents no evidence for preferential beneficial effects based on incidence of bacteriuria.
Another solution shown to have some promise in UTI prevention was studied as a combination therapy, both with antiseptic properties. Krebs et al. (1984) investigated the potential of a 5% hemiacidrin solution instilled as an intravesicular acidifying agent at each intermittent catheterization combined with oral administration of methenamine mandelate (2 mg four times daily) in persons undergoing SCI inpatient rehabilitation. As compared to individuals undergoing no bacterial prophylaxis, the pH of urine was significantly reduced (p<0.01) and there was a lower rate of symptomatic UTI (p<0.05) and less bacteriuria as indicated by a reduced number of positive cultures (p<0.001). The role of hemiacidrin solution alone in these findings remains uncertain.
In contrast to these findings, as part of a double-blind, placebo-controlled RCT (n=305) conducted by Lee et al. (2007), oral methenamine hippurate (another formulation of methenamine as an antiseptic) was generally ineffective in preventing symptomatic UTIs. In this well-conducted large sample trial, active and placebo formulations (oral tablet) of both methenamine hippurate and a cranberry preparation were compared as to the occurrence of asymptomatic UTI (up to 6 months) as a primary end-point. There were no statistically significant effects with either treatment alone or in combination as compared to placebo.
These various conflicting results suggest the specific antiseptic agent, alone or in combination with others, and its mode of administration might be important in determining clinical effectiveness and that the practice of antiseptic bladder instillation along with other methods of delivery, dismissed as ineffective by some or in general practice by others (Pearman et al. 1988; Castello et al. 1996; Schlager et al. 2005; Lee et al. 2007), requires further study.
Botulinum toxin therapy has been discussed extensively in this chapter as it relates to improving urodynamic parameters. It has also been studied for the use of reducing UTIs post SCI in two pre-post studies. Both Jia et al. (2013) and Game et al. (2008) reported that after treatment with 300 U into the detrusor, indivudals had significantly fewer UTIs at follow-up. Further, Jia et al. (2013) reported that the reduction of UTIs was significant only in patients with detrusor overactivity but not in those without norm-active detrusors.
There is level 2 evidence (from one RCT: Sanderson & Weissler 1990a) that daily body washing with chlorohexidine and application of chlorhexidine cream to the penis after every catheterization versus using standard soap reduces bacteriuria and perineal colonization.
There is level 1b evidence (from one RCT: Waites et al. 2006) that bladder irrigation with neomycin/polymyxin or acetic acid is not effective for UTI prevention.
There is level 2 evidence (from one RCT: Castello et al. 1996) that bladder irrigation with ascorbic acid is not effective for UTI prevention.
There is level 4 evidence (from one pre-post study: Schlager et al. 2005) that phosphate supplementation is not effective for UTI prevention.
There is level 2 evidence that bladder irrigation with trisdine (RCT: Pearman et al. 1988), kanamycin-colistin (RCT: Pearman et al. 1988) or a 5% hemiacidrin solution combined with oral methenamine mandelate (2 mg four times daily; RCT: Krebs et al. 1984) may be effective for UTI prevention.
There is level 1b evidence (from one RCT: Lee et al. 2007) that oral methenamine hippurate, either alone or in combination with cranberry, is not effective for UTI prevention.
There is level 4 evidence (from two pre-post studies: Jia et al. 2013; Game et al. 2008) that 300 U botulinum toxin type A may reduce UTIs among individuals with neurodestrusor overactivity post SCI.