n a recent surgery, one
I
author of this study noted
poor urine flow after kid-
ney reperfusion in a liver-
kidney transplant patient; how-
ever, after straightening the urine
drainage tubing to empty the
urine that had accumulated in
the generally U-shaped depend-
ent loop in the Foley drainage
tube, the rate of urine outflow
from the bladder appeared to
increase. This sequence of events
raised a simple question with
clinical implications: couldered as passive drains that reli-
ably channel urine from the blad-
der to the urine collection bag? At
a minimum, obstruction to urine
outflow may cause patient dis-
comfort and may also predispose
a patient to a catheter-associated
urinary tract infection (CAUTI).
Informal experimentation with a
commercial urine drainage sys-
tem led to the hypothesis that sig-
nificant back-pressures might
potentially harmful back-pres-
sures sometimes exist in urine
drainage systems that are consid