Retrograde contamination and practical handling of urine-meters: a comparison of three systems for the measurement of hourly diuresis in an experimental bladder-drainage model and in clinical use.
OBJECTIVE
To compare three different urine metering systems for their ability to prevent retrograde contamination in an in vitro model of a closed urinary drainage system and for qualities important to their practical handling in a clinical setting.


METHODS
Using three urine-meters (the Braun Ureofix 511, the Kendall Curity 4000 and the Unoplast Unometer 500) the in vitro model was constantly flushed with a solution of Mueller-Hinton broth diluted with saline. On the first day, the urine collecting bag was inoculated with 10(8) cells of Pseudomonas aeruginosa. The system was operated for 12 days with daily sampling of the model bladder to detect any contamination. After 12 days the experiment was stopped and sampling performed at various locations, including the urine-meter and the tubing. Nine of each type of urine-meter were tested, i.e. three in three different experiments. In the clinical study, 45 patients were randomized to each of the three urine-meters and the nurses attending them were asked to complete a questionnaire on the practical handling of the urine-meters.


RESULTS
When the urine-meters was omitted from the model system, the 'bladder' became contaminated with the test bacteria within 3 days. None of the nine Unometer 500 systems became contaminated, compared with four of each of the other two systems (P < 0.05). In clinical use, the Unometer 500 and Ureofix 511 were easier to suspend and empty than was the Curity 4000. The Unometer 500 was significantly easier to handle when the collecting bag was emptied.


CONCLUSIONS
Urine-meters can prevent retrograde contamination in a closed bladder-drainage model, but the degree of prevention depends upon the type of urine-meter. In daily practice, there were differences in the ease of suspension of the systems and in the emptying of the urine-meter and collecting bag.
Rasmussen
A
A
Department of Urology, Gentofte Hospital, University of Copenhagen, Denmark.
Frimodt-Møller
N
N
Espersen
F
F
Roed
M
M
Frimodt-Møller
C
C
D001291:Attitude of Health Personnel; D004231:Diuresis; D004866:Equipment Contamination; D004867:Equipment Design; D006801:Humans; D008954:Models, Biological; D011552:Pseudomonas Infections / Q000517:prevention & control; D011550:Pseudomonas aeruginosa; D001743:Urinary Bladder / Q000502:physiology*; D014552:Urinary Tract Infections / Q000451:nursing / Q000517:prevention & control; D014556:Urine; D014572:Urology / Q000295:instrumentation*