[Migration speed of uropathogens : Determination in the ureteral splint in a practice-like in vitro model]. / Wanderungsgeschwindigkeit von uropathogenen Erregern : Bestimmung im Ureterkatheter im praxisnahen In-vitro-Modell.

BACKGROUND: A urostomy with an ileum conduit or a skin fistula leads to a high infection risk for the kidneys and the ureter of the patient. Therefore, the prevention of retrograde colonization of the artificial drain (splint) with e. g. contaminated urine is the most important objective of infection prevention measurements. We performed an in vitro experiment to determine the migration speed of clinically relevant bacteria in a commercially available splint catheter system. METHODS: The migration speed of bacteria in commonly used splint catheters was determined in a practice-like in vitro model. Two storage vessels were connected with splints. The second vessel contained a bacterial suspension of the test bacteria Escherichia coli, Proteus mirabilis, and Staphylococcus aureus in artificial urine. The two vessels were incubated at 36 °C for 24-72 h. The microbial count in the catheters was determined after each experiment to investigate the migration distance. RESULTS: The average migration speed was 0.63 cm/h for E. coli, 0.80 cm/h for S. aureus, and 0.94 cm/h for P. aeruginosa. This results in a colonization distance of approximately 80 cm in 3 days. CONCLUSION: If the system, e. g., the stoma pouch is contaminated, it can be expected that during the common application time of a splint of 10-14 days, the complete splint will be contaminated due to the high bacteria migration speed. Consequently there is a high infection risk for kidneys and ureters. A return stop feature in the stoma pouch should minimize this risk. However, it is of upmost importance to not applying the splint through the return stop to prevent any contact with potentially contaminated urine.

[The influence of viscosity of synthetic urine on the flow rate through catheters]. / Der Einfluss der Viskosität von künstlichem Harn auf die Durchflussgeschwindigkeit in Kathetern.

BACKGROUND: There are special requirements for draining a pouch, e.g. length, flexibility and ability to drain highly viscous urine. METHODS: We checked in vitro the flow time of pure and synthetic urine thickened with hydroxyethylcellulose (0.125% and 0.250%, HEC) on selected catheters. RESULTS: We found for SpeediCath Compact Male (SCCM) as a CH12 catheter the shortest flow times for undiluted and urine thickened with 0.125% and for SafetyCath Plus for urine thickened with 0.250%. For catheters with CH14 we found significantly shorter flow times for all tested solutions. The flow time does not depend on amount and area of the catheter eyes; we found no difference in the flow time for 4-eye (MobiStom) and 2-eye catheters.