A pregnant woman who, in the immediate postpartum period, developed hemorrhagic shock due to uterine atony with anuric acute kidney injury (AKI stage III). Blood tests showed criteria for hemolytic anemia and thrombocytopenia.

After ruling out prerenal etiologies and correcting systemic congestion (VExUS study) as possible causes of AKI, the patient did not improve. Renal Doppler ultrasound revealed cortical thickening with loss of corticomedullary differentiation, interlobar arterial flow with systolic peaks (elevated arterial resistance index [RI>0.7]), and monophasic interlobar venous flow (Figs. 1 and 2). Renal parenchymal involvement of autoimmune etiology was suspected and subsequently confirmed by the Hematology Department as thrombotic microangiopathy. After treatment with eculizumab, renal Doppler findings improved, as shown in the images.

Figure 1.

Systolic peaks (*) and monophasic venous flow (**) in the renal interlobar arteries, which normalized (RI of 0.57 and phasic venous flow) after eculizumab.

Figure 2.

Cortical thickening and loss of corticomedullary differentiation (blue arrow).