Irrigating fluid absorption during percutaneous nephrolithotripsy

Background: The most common complication during percutaneous nephrolithotri psy (PNL) is the destruction of organ structures with extravasation of the irrigation fluid into the retroperitoneal space. Consequently, there is an increased risk of a urosepsis and a complicated therapeutic course. In this study we aimed to show that extravascular absorption could be differentiat ed from intravascular absorption due to their unique absorption characteris tics, and that these characteristics enable a prediction of possible post-o perative complications. Methods: In a prospective study of 31 patients with PNL, ethanol was added to the irrigating fluid and blood ethanol concentration (BEC) was measured by gas chromatography during the endoscopic procedure and in the recovery r oom. Following the guidelines of Hahn, patients were divided into two group s: group EVA, in whom extravasation had occurred with subsequent absorption ; group IVA, those with intravascular absorption, patients' post-operative progress along with diagnoses of renal perforations or bleeding, or signs o f infection or sepsis, were comprehensively listed. Results: EVA was diagnosed in 19 cases, and IVA in 12 cases. Maximum BEC le vels were achieved after 20 min (median) in the IVA group, and 75 min in th e EVA group (P<0.05). Apart from their significantly higher demand for opio ids (P<0.05), EVA patients had been hospitalised for a substantially and si gnificantly longer period of time (P<0.01). Although without statistical si gnificance, there was a higher rate of peri-operatively confirmed complicat ions and prolonged intensive therapeutic treatment in the extravasation gro up. Conclusion: Retroperitoneal extravasation can be identified by using ethano l monitoring during and after PNL. Afflicted patients require considerably longer hospitalisation, probably because of the additional injury to surrou nding organ structures.