To the Editor:

We read with interest the study by Mazda et al. [1] regarding postoperative acute kidney injury (AKI) in parturients with severe preeclamsia. We would like to discuss the clinical implication of the study. First, the effect of hydroxyl ethyl starch (HES) administration was not evaluated fully. Clinical outcomes other than AKI were not compared with a control group. Although not clearly shown, the number of patients with proteinuria or elevated serum creatinine seems to be very small. The incidence of AKI and the impact of HES on AKI may be different in the more selected patients with severe preeclampsia with renal dysfunction [2]. Second, the serum creatinine measurement may not be a reliable estimation of glomerular filtration rate (GFR) in these parturients [3]. Delivery itself and different oral intakes after surgery may influence serum creatinine and following creatinine after delivery may not be accurate. GFR increases up to 50% during pregnancy and continue at levels 20% above normal at postpartum week [4]. Diagnosis of AKI in these patients using other measurement of GFR or more sensitive biomarkers may be required.