Retroperitoneal leakage as a cause of acute ultrafiltration failure: its associated risk factors in peritoneal dialysis.

Background: Ultrafiltration failure is an important clinical problem in patients on maintenance peritoneal dialysis (PD) and is associated with high morbidity and mortality. Acute ultrafiltration failure (AUFF) is usually secondary to mechanical problems with the peritoneal catheter or peritoneal leakage. Retroperitoneal leakage (RPL) is an important cause of AUFF and often poses diagnostic difficulty. Herein we analyze the incidence of AUFF secondary to RPL in our centers and study its associated risk factors.

Methods: After excluding causes due to mechanical problems with the peritoneal catheter, patients complicated by AUFF underwent computerized tomographic peritoneography (CTP) or magnetic resonance imaging of the peritoneal cavity (MRP) to determine any RPL. Other patients on maintenance PD without RPL served as controls for comparison of risk factors. Demographic and peritoneal membrane characteristics, including history of hernia and pleuroperitoneal leakage, were analyzed.

Results: During the 5-year study period, 36 patients in a cohort of 743 patients on maintenance PD developed AUFF. 23 of these 36 patients were found to have RPL, which was confirmed by either CTP (n = 16) or MRP (n = 7). The duration of PD at the time of RPL and the dialysate-to-plasma ratio of creatinine at 4 hours were 49.3 +/- 24.5 (range 0.5 - 87.9) months and 0.70 +/- 0.09 respectively. Incidences of hernia (52.2%) and pleuroperitoneal communication (34.8%) were significantly higher than in PD patients without RPL (13% and 7% respectively, p = 0.001). Logistic regression analysis identified hernia and pleuroperitoneal communication as the risk factors for RPL. The odds ratios for RPL with hernia and pleuroperitoneal communication were 6.62 [95% confidence interval (CI) 2.35 - 18.69, p < 0.001] and 6.23 (95% CI 1.83 - 21.19, p = 0.003) respectively.

Conclusion: RPL was not uncommon in patients with AUFF. A high index of suspicion for RPL is needed in the management of patients with history of hernia or pleuroperitoneal communication presenting with AUFF.