Decompressive Cystocentesis in Cats with Urethral Obstruction

In the Literature

Reineke EL, Cooper ES, Takacs JD, Suran JN, Drobatz KJ. Multicenter evaluation of decompressive cystocentesis in the treatment of cats with urethral obstruction. J Am Vet Med Assoc. 2021;258(5):483-492.

The Research …

In feline patients in which urethral obstruction lasts longer than ≈24 hours, postrenal azotemia and other complications (eg, hyperkalemia, hyperphosphatemia, metabolic acidosis) are likely.¹ Several aspects of urethral obstruction, including optimal management, remain controversial or lack an adequate evidence base.²

There are several potential benefits of performing decompressive cystocentesis prior to urethral catheterization in a cat,^1-3 including sterile collection of urine for urinalysis and relief of urinary tract pressure, which improves glomerular filtration and reduces further urinary tract damage. Relief of pressure may also result in easier urinary catheterization and reduced risk for urethral damage. For patients in which urinary catheterization and standard of care are of financial concern, repeat cystocentesis and supportive therapy may lead to spontaneous recovery in an appreciable proportion of cats.⁴

Although previous studies suggested that decompressive cystocentesis in cats with urethral obstruction is safe and unlikely to lead to bladder tears, bladder rupture, or uroabdomen,^3-5 this is the first prospective, randomized, controlled study to evaluate procedure safety and efficacy.

In this study of 88 male cats, decompressive cystocentesis was performed in 44 cats with urethral obstruction before urinary catheterization, and 44 other cats had urinary catheterization without prior cystocentesis. A median of 68.5 mL (range, 15-162 mL) of urine was removed during cystocentesis. As in previous studies, decompressive cystocentesis did not appear to be associated with increased risk for abdominal effusion, and there was no appreciable evidence of uroabdomen^3-5; however, the procedure did not have a significant effect on the length of time to perform urinary catheterization or the ease in which catheterization was performed. It was also not associated with improvement of metabolic derangements or clinical outcomes.

… The Takeaways

Key pearls to put into practice:

• When cystocentesis is performed carefully by experienced clinicians, there appears to be minimal risk for significant bladder leakage or rupture in cats with urethral obstruction.

• Although decompressive cystocentesis appears to be safe, this study found no evidence that it helped to improve the speed or ease with which subsequent urethral catheterization could be performed.

• Decompressive cystocentesis also had no significant value in improving metabolic derangements or clinical outcomes, possibly because kidneys require hours to days to regain normal function. Thus, other medical measures should be the focus of managing severe metabolic derangements.