A 50-year-old man who had problems with urgency as well as frequent and difficult urination for the past 10 years recently experienced some relief with tamsulosin (Flomax). Time between urinations, which had ranged from 20 to 90 minutes, has doubled, and much of the straining is gone. Ultrasounds show increasing prostate size, from 30 cc in 2000 to 48 cc in 2006. The pre-void bladder volume increased from 506 cc to 627 cc, and the post-void volume increased from 307 cc to 538 cc on the first attempt and 509 cc on the second attempt despite the fact that the patient estimated his voided volume at 500 and 250 cc, respectively. My questions: (1) What are the risks of bladder failure? And what are the warning signs? What tests should be done? (2) Is it possible the bladder was filling almost as quickly as it was emptying? (3) What are the risks and benefits of a urodynamic study? (4) What could trigger bouts of frequent urination (every 20 minutes for up to two hours) to the point of dehydration?
—Robert Versoloff, MD, Bangor, Maine
This young patient would seem to have significant symptoms of benign prostatic hyperplasia that, over time, have resulted in bladder decompensation. The reason for the frequency/urgency is likely to be incomplete emptying causing a refilling of the bladder in a short interval. Although Flomax will often help ease the subjective symptoms in such a patient, it may be too late to completely restore a normally functioning bladder.
The risks of copious residual urine are infection, development of high-pressure voiding leading to reflux or bladder diverticulae, and, perhaps most importantly, hydronephrosis and renal insufficiency. If the patient has hydronephrosis or renal insufficiency, long-term catheter drainage could be tried to see if the situation is reversible. In the appropriate patient, this can be accomplished by intermittent self-catheterization, trying to keep all total volumes (any voided volume plus the residual volume) below 400 cc. I would also choose maximal medical management Flomax 0.8 mg a day along with either finasteride (Proscar) or dutasteride (Avodart). The patient might benefit from transurethral resection of the prostate or an equivalent procedure. A bladder can be so chronically overstretched that it never recovers its contractility. Factors that contribute to this possibility are underlying medical illnesses (e.g., diabetes, multiple sclerosis) and medications (e.g., lithium).
Although urodynamics may be helpful in the future, I would not recommend them at this time.
—David T. Noyes, MD (102-5)