Urinary retention in unilateral total knee arthroplasty: Comparison between continuous epidural analgesia and single-shot femoral nerve block

Objective: To compare the frequency of urinary retention and requirement of bladder catheterization in patients undergoing total knee arthroplasty while receiving either continuous epidural analgesia or single-shot femoral nerve block.Study design: Randomized controlled study.Place and duration of study: Operating Rooms of Aga Khan University Hospital, Karachi, from January 2014 to January 2015.Methodology: Patients were randomized in two groups of 30 each, i.e. epidural group (group E) or femoral nerve block group (group F). Baseline parameters were recorded. Postoperatively, patients were followed for upto 24 hours to collect the data regarding urinary retention. Final outcome was taken at 24 hours postoperatively. Data was analyzed to compare the frequency of urinary retention between the two groups.Results: The average age of the patients was 59.58 ±5.85 years. There were 28 (46.7%) male and 32 (53.3%) female patients. Frequency of urinary retention was significantly high in Group E than Group F (46.7% vs. 6.7%; p=0.0005).Conclusion: Single-shot femoral nerve block offers a more favorable profile in terms of postoperative urinary retention when compared to continuous epidural analgesia