Absorption of irrigating fluid during percutaneous transrenal lithotripsy.

Twenty-eight patients who underwent percutaneous lithotripsy with isotonic mannitol solution as the irrigating fluid were studied. Intraoperative intravenous and total absorption of irrigating fluid was estimated from postoperative analyses of plasma and urinary concentrations of mannitol. Most operating times were short and only minor fluid absorption was recorded. In six cases, however, the fluid absorption exceeded 100 ml and two of these had a maximal calculated absorption of more than 1000 ml (1220 and 1860 ml, respectively). Intraoperative bleeding was a warning sign of absorption of irrigating fluid.