Effect of urinary bladder lavage on in-hospital recurrence of urethral obstruction and durations of urinary catheter retention and hospitalization for male cats

OBJECTIVE To evaluate the effect of urinary bladder lavage on in-hospital recurrence of urethral obstruction (UO) and durations of urinary catheter retention and hospitalization for male cats. DESIGN Randomized controlled clinical trial. ANIMALS 137 male cats with UO. PROCEDURES Following random allocation, cats either did (flush group; n = 69) or did not (no-flush group; 68) undergo urinary bladder lavage with saline (0.9% NaCl) solution after alleviation of the obstruction and placement of a urethral catheter. Signalment, prior history of UO, presence of crystalluria, difficulty of urinary tract catheterization, in-hospital UO recurrence rate, and durations of urinary catheter retention and hospitalization were compared between the flush and no-flush groups. RESULTS Baseline characteristics did not differ significantly between the 2 treatment groups. The in-hospital UO recurrence rate (9/69 [13%]) and median durations of urinary catheter retention (37 hours; range, 3 to 172 hours) and hospitalization (3 days; range, 0.5 to 12 days) for the flush group did not differ significantly from the in-hospital UO recurrence rate (13/68 [19%]) and median durations of urinary catheter retention (36 hours; range, 1 to 117 hours) and hospitalization (3 days; range, 1 to 9 days) for the no-flush group. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that, for male cats with UO, urinary bladder lavage at the time of urethral catheterization had no significant effect on in-hospital recurrence rate of the condition, duration of urinary catheter retention, or duration of hospitalization; however, additional studies are necessary to validate or refute these findings. In male cats, UO is a life-threatening emergency that occurs as a complication of feline lower urinary tract disorders. Although UO in male cats occurs commonly, consensus regarding the most appropriate way to medically manage affected cats is lacking, as is evidence to formulate standardized recommendations.1 Consequently, clinicians are likely to manage affected cats on the basis of procedures with which they are familiar or that are routinely performed at their place of employment. A frustrating complication associated with UO is recurrence of the obstruction, which can develop in the short or long term. Recurrence of UO can lead to prolonged or repeated hospitalization or surgical intervention (eg, perineal urethrostomy), resulting in an increase in morbidity, financial commitment, and risk for euthanasia.2–4 For male cats with UO, most clinicians recommend strategies for decreasing the risk for recurrence, such as dietary changes, pharmacological treatments, and environmental modifications, following initial treatment.1,5,6 Despite those recommendations, recurrence of UO is common, particularly in the short term while affected cats are hospitalized for the initial occurrence. Some clinicians believe that lavaging the urinary bladder with saline (0.9% NaCl) solution at the time the urinary tract is unblocked and a urinary catheter is placed may help to remove or dilute debris, mucous plugs, urinary crystals, bacteria, or blood clots, thereby decreasing the risk for recurrence of the UO. To our knowledge, the efficacy of urinary bladder lavage on in-hospital recurrence of UO in male cats has not been evaluated. The objective of the study reported here was to evaluate the effect of urinary bladder lavage at the time of urinary tract catheterization for treatment of UO in male cats on the in-hospital recurrence rate of the condition and durations of urinary catheter retention and hospitalization. The null hypotheses were that urinary bladder lavage would have no effect on in-hospital UO recurrence, duration of urinary catheter retention, and duration of hospitalization