Objectives To identify the optimum volume of acidic bladder washout solutio
n to disserve catheter encrustations and to compare the effectiveness of di
fferent bladder washout delivery devices.
Materials and methods Urinary catheter encrustation was generated in vitro
using a model of the catheterized bladder adapted from previous work. An ac
idic bladder washout solution (Suby G) was applied via the catheter in the
model and retained for 15 min. The amount of encrusting material dissolved
was measured by colorimetric analysis of the magnesium and calcium content
of the solution returned after the washout procedure. The relative effectiv
eness of different volumes of washout: solution and different washout deliv
ery devices (Optiflow. Bard Ltd, Crawley; UroTainer, B/Braun Medical Ltd, A
ylesbury; and a bladder syringe) in dissolving catheter encrustations was c
ompared to the 'standardized' conditions commonly used in practice.
Results There was no statistically significant difference between washouts
with 100 mL and washouts with 50 mL for any of the delivery devices tested.
Gentle agitation with 50 mt Suby G did not significantly improve the disso
lution of encrustation but the total amount of material dissolved when two
washouts with 50 mL Suby G were used sequentially was significantly better
than a single washout with either 100 mL or 50 mL.
Conclusions Under controlled laboratory conditions, smaller volumes of acid
ic bladder washout solution (50 mL) are as effective as the 100 mL commonly
used in practice, but two sequential washouts with 50 mL are more effectiv
e than a single washout. The newly designed Optiflow delivery device is at
least as effective as the other devices tested. This study provides new evi
dence which may contribute to decision-making by practitioners in relation
to catheter care.