Bacteriological safety and cost-effectiveness of a nonrefluxing valve in the irrigation system during outpatient flexible cystoscopy

Objective To critically evaluate the infection rate associated with the use of a nonrefluxing irrigation system for outpatient flexible cystoscopy, by comparing it with conventional irrigation systems, and to determine the co sts and benefits of this system of irrigation delivery. Patients and methods All patients undergoing flexible cystoscopy on schedul ed outpatient lists were considered for inclusion in the study; 143 patient s of 220 undergoing cystoscopy fulfilled the study criteria. The study grou p of patients underwent cystoscopy with a new single-use nonrefluxing valve inserted into the same irrigation delivery system that was used for the wh ole endoscopy session, and the control group had the complete irrigation sy stem changed after each endoscopic examination. Midstream urine samples wer e taken for analysis before cystoscopy and again 3-4 days later. Infection was defined as a pure growth of greater than or equal to 10(5) organisms/mL , with associated pyuria defined as greater than or equal to 10 pus cells p er high power microscopic field. Results Complete data were available on 133 patients, with a further nine b eing excluded from the statistical analysis because they had a pre-existing urinary tract infection, leaving 64 patients in the study and 69 in the co ntrol groups. The overall infection rate for flexible cystoscopy was 3.2%, with no significant difference between the study and control groups. Cost s avings of >35% can be expected using the non-refluxing valve method of irri gation delivery. Conclusion The nonrefluxing valve caused no detectable increase in patient morbidity from bacterial infection when compared with conventional irrigati on systems for flexible cystoscopy, and can save considerable costs.