The blocking urinary catheter: the role of variation in urine flow.

OBJECTIVES

To relate blockage of the urinary catheter to urine chemistry.

PATIENTS AND METHODS

Of 44 patients (age range 19-72 years) with an indwelling urinary catheter, 21 were troubled by frequent blockage and 23 experienced no blockage. Variation in urinary pH and calcium concentration were determined during a 24 h period and related to the occurrence of blockage using discriminant analysis.

RESULTS

The maximum pH and calcium concentrations observed, or the maximum discriminant factors calculated, correctly discriminated 91% of patients (95% CI, 78-97%).

CONCLUSION

Attention to volume and variability of fluid intake by the patient should have a major impact on the incidence of blockage of the indwelling urinary catheter.