Post-operative urinary retention after lower extremity arthroplasty and the peri-operative role of selective alpha-1 adrenergic blocking agents in adult male patients: a propensity-matched retrospective cohort study

PurposeThe purpose of this study was to determine whether male patients taking pre-operative selective alpha-1 adrenergic blocking agents have a lower likelihood of developing post-operative urinary retention (POUR) and a shorter length of hospitalization following lower extremity arthroplasty.MethodsA retrospective cohort study was conducted of patients who underwent primary or revision total hip or knee arthroplasty, or unicompartmental knee arthroplasty at an academic institution from January 2002 to May 2014. A cohort of male patients aged 35 and older who were taking a selective alpha-1 blocker prior to surgery (N = 229) were compared with a control group (N = 330) not taking one of these medications. Propensity score-matched logistic regression was performed to isolate the effect of taking a selective alpha-1 blocker on POUR.ResultsWhen evaluating for the outcome of POUR while controlling for age, hypertension, benign prostatic hyperplasia, urinary tract infections, type of anaesthesia, and procedure, those patients taking an alpha-1 blocker had a 12.1% decreased relative risk (95% CI 3.4 to 20.8%; p = 0.007) of developing POUR compared with patients not taking these medications. Mean length of stay was 3.8 days (95% CI 3.6 to 4.1) in the cohort taking selective alpha-1 blockers compared with 4.7 days (95% CI 4.4 to 4.9) for the control cohort.ConclusionsAfter controlling for known risk factors for the development of POUR, the use of selective alpha-1 blockers pre-operatively reduces the risk of developing urinary retention after lower extremity arthroplasty and is associated with a 1-day decreased length of stay.