Management of urinary retention: rapid versus gradual decompression and risk of complications.

The literature was reviewed to quantify the risk of complications related to the relief of obstruction in urinary retention. We also sought to determine whether the risk of complications is higher with rapid or gradual decompression (or "clamping") of the obstructed urinary bladder. The medical literature was identified by a search of the MEDLINE database and a manual review of the bibliographies of the identified articles. Studies show that, after quick, complete relief of obstruction, hematuria occurs in 2 to 16% of patients; however, clinically significant hematuria is rare. After relief of obstruction, blood pressure often decreases, but it usually normalizes and does not progress to clinically significant hypotension. Postobstructive diuresis occurs after relief of obstruction in 0.5 to 52% of patients; however, it is easily managed and rarely of clinical significance. We were unable to identify any randomized controlled studies that directly compared quick, complete emptying with gradual emptying of the obstructed bladder. Moreover, we identified no studies supporting the practice of gradual emptying of the obstructed bladder. The available published studies support quick, complete emptying for relief of the obstructed urinary bladder. We conclude that hematuria, hypotension, and postobstructive diuresis may occur after decompression of the obstructed urinary bladder, but these complications are rarely clinically significant. Quick, complete emptying of the obstructed bladder is safe, simple, and effective and is recommended as the optimal method for decompressing the obstructed urinary bladder. Prudent, supportive care is needed for all patients, with special attention to elderly patients and those with hypovolemia.