A pilot study of the effect of the Queen's Square external bladder stimulator on urinary retention after knee...

Postoperative urinary retention remains an important problem after major orthopaedic surgery and can increase morbidity. External vibration applied to the suprapubic region has improved bladder emptying and urinary symptoms in patients with neurogenic bladders. Forty-three patients undergoing elective major knee surgery were randomly assigned to receive either a Queen's Square bladder stimulator or placebo device for 24 h postoperatively. No statistically significant differences in rates of urinary retention could be demonstrated in the bladder stimulator group compared to the placebo group (41% and 33%, respectively). There were no differences between the two groups when analysed for prostatic symptoms, type and effectiveness of analgesia and fluid balance. We conclude that, while the Queen's Square external bladder stimulator may be effective in treating chronic urinary retention associated with a neurogenic bladder, it does not appear to be effective in preventing postoperative urinary retention.