Pregnancy-related acute kidney injury: mortality and survival of patients treated at a maternal intensive care unit.

INTRODUCTION

Pregnancy-related acute kidney injury (AKI) can be defined as the abrupt decline in renal function during pregnancy or the postpartum period. It remains a relevant cause of fatal complications in obstetric patients. This study aimed to determine the incidence of pregnancy-related AKI in a maternal intensive care unit (ICU) as well as the associated risk factors for dialysis therapy and maternal mortality according to the KDIGO classification system.

METHODS

Retrospective analysis of observational data prospectively collected from January/2014 to April/2016 in a maternal ICU in a public tertiary maternal hospital in Brasília, Federal District, Brazil. All consecutive patients diagnosed with pregnancy-related AKI were included. Cases of renal failure before pregnancy or kidney transplantation were excluded.

RESULTS

Of the 619 admitted patients, pregnancy-related AKI was present in 172 cases (27.8%). One hundred and ten patients were classified as KDIGO 1 (64.0%), 43 as KDIGO 2 (20.9%) and 22 as KDIGO 3 (15.1%). KDIGO stages 2 and 3 were less frequent than KDIGO stage 1 in patients with gestational hypertension (p = 0.0010). Thirteen patients required hemodialysis (7.6%). Higher APACHE II (p = 0.0399) and SOFA (p = 0.0297) scores, hypovolemic shock (p = 0.0189) and septic shock (p = 0.0204) were independently associated with dialysis therapy (hemodialysis in all cases), 15 patients died (8.7%). Time to death was shorter in patients with a higher KDIGO stage (p = 0.002). Norepinephrine (p = 0.0384) and hemodialysis therapy (p = 0.0128) were independently associated with maternal mortality.

CONCLUSIONS

The incidence of pregnancy-related AKI remains high in the maternal ICU setting. Septic shock, hypovolemic shock, and higher APACHE II and SOFA scores were independently associated dialysis therapy (hemodialysis in all cases). KDIGO stages 2 and 3 were less frequent than KDIGO stage 1 in patients with gestational hypertension. Norepinephrine and hemodialysis therapy were independently associated with maternal mortality in patients with pregnancy-related AKI. KDIGO stage 3 was associated with higher maternal mortality.