Spectrum of urodynamic abnormalities and renal function changes in adult men with non-neurogenic urinary retention

The purpose of this study was to identify abnormalities in bladder and renal function in men with urinary retention presumed to be due to BPH.

In this retrospective analysis, urodynamic studies (UDS) and renal function were evaluated. Bladder contractility and compliance and the severity of bladder outlet obstruction (BOO) were determined from urodynamics. Renal function (BUN, creatine, eGFR) was assessed prior to retention, at the time of presentation and after urodynamic evaluation.

Of 87 patients with evaluable UDS, 48% did not demonstrate detrusor activity during testing while 52% showed some detrusor contractile activity. Of these, 23% did not have BOO. Diminished bladder compliance was detected in 56%. In the entire cohort, BUN, serum creatinine, and eGFR were significantly changed during retention but were restored after catheterization. In older patients (>75 years), BUN and creatinine during retention were significantly higher, and eGFR was significantly lower compared to younger patients, but renal function after catheterization was not different between age groups. No significant correlations were found between renal function measurements and bladder compliance or age.

The urodynamic spectrum in men with urinary retention ranged from detrusor acontractility to varied degrees of contractility associated with outlet obstruction spanning from equivocal to severe. Moreover, prompt relief of retention restores renal function to baseline levels, regardless of age. This study indicates that prostatic obstruction may not be the only cause of urinary retention in adult men presumed to have BPH and illustrates the value of urodynamic assessment prior to potentially failure-prone surgical interventions.