Relationship between microangiopathic intravascular hemolysis and kidney dysfunction in patients with preeclampsia

Abstract

Background: Preeclampsia is today one of the most important causes of maternal morbidity and mortality. Renal dysfunction is one of the main complications in such patients and is a marker of severity of the process. The microangiopathic intravascular hemolysis is a manifestation of severe endothelial dysfunction and is related to perfusorious systemic problems in patients with preeclampsia. Microangiopathic intravascular hemolysis may be a marker associated with renal dysfunction. Objective: To determine if thrombotic intravascular hemolysis is a marker of bad evolution in patients with preeclampsia in the immediate postpartum. Material and method: An observational study included patients with preeclampsia admitted to the Obstetric Unit. Patients were classified into two groups: with renal dysfunction (serum creatinine levels ≥ 0.9 mg/dL) or normal renal function. Microangiopathic intravascular hemolysis was analyzed if patients presented positive peripheral blood smear, hemoglobinuria, elevated levels of lactic acid dehydrogenase and thrombocytopenia. Results: 81 patients with preeclampsia were included, at entering to Obstetric Unit 23 (28.3%) had renal dysfunction and 58 (71.7%) had normal renal function. At the 24 hours after partum 35 patients (43.2%) had renal dysfunction and 46 (56.8%) had normal renal function. Microangiopathic intravascular hemolysis was presented in six patients at entering and after 24 hours (7.4%). Al entering 17.3% and 3.4% of patients with renal dysfunction and normal renal function, respectively, presented microangiopathic intravascular hemolysis, OR 5.89 (95 CI 0.9-34.7) p = 0.031. At the 24 hours after partum 11.4% had renal dysfunction and 4.3% had normal renal function, OR 2.83 (95 CI 0.4-16.4) p = 0.2. In regard to peripheral blood smear, to the admission of the patients, 60.8% had renal dysfunction and 36.2% had normal renal function, OR 2.74 (CI 1.01-7.40) p = 0.0043. To 24 hours, 60% had renal dysfunction and 30.4% had normal renal function, OR 3.42 (95 CI 1.36-8.62) p = 0.008. Conclusion: Microangiopathic intravascular hemolysis has an inconsistent behavior in relation to renal dysfunction, in contrast to the presence of blurred cells on the peripheral blood smear.