Acute kidney injury requiring dialysis in obstetric patients: a series of 55 cases in Brazil.

Objective: To investigate the risk factors associated with oliguria and death in obstetric patients with acute kidney injury (AKI).

Methods: The study group included all obstetric patients with AKI, under dialytic treatment, in Hospital Geral César Cals, Fortaleza, Brazil, from January 2000 to December 2006. AKI were classified according to the RIFLE criteria. Univariate and multivariate analysis were performed to investigate the factors associated with oliguria and death.

Results: A total of 55 patients were included. Their average age was 26.2 +/- 6.7 years. The main etiologies of AKI were pregnancy-related hypertension (41.8%), HELLP syndrome (40%), puerperal sepsis (14.5%), abruption placentae (9.1%), hemolytic uremic syndrome (9.1%) and thrombotic thrombocytopenic purpura (5.5%). Oliguria was observed in 36 cases (65%). Death occurred in 17 cases (30.9%). Factors associated with oliguria were, diagnosis of HELLP syndrome, hyperbilirubinemia and death. Factors associated with death were, presence of puerperal sepsis, hyperbilirubinemia, hypotension, oliguria and low levels of HCO(3).

Conclusion: AKI is a rare but potential fatal complication in obstetric patients. RIFLE criteria seem to have association with mortality. There are important factors associated with oliguria and death, which must be prompt recognized to the institution of adequate therapeutic measures.