ABSTRACT
Objective:To estimate the incidence and risk factors of acute kidney injury (AKI) in preterm infants, and provide basis for better evaluation and treatment of renal function in preterm infants.Methods:All the hospitalized premature infants who were admitted to three research centers (Department of Neonatology at Beijing Children′s Hospital; Department of Neonatology at Beijing Obstetrics and Gynecology Hospital; Department of Neonatology at Shunyi Maternal and Children′s Hospital of Beijing Children′s Hospital)from January 1, 2017 to June 30, 2019 and had more than two serum creatinine values or urine output were included.The incidence of AKI in preterm infants was calculated and the difference among different gestational weeks was compared.Preterm infants were divided into AKI and non-AKI groups according to AKI diagnostic criteria, and the clinical characteristics between two groups were compared, and the risk factors of AKI in preterm infants were analyzed.Results:A total of 763 premature infants were included in the analysis.Twenty two cases were diagnosed with AKI.The incidence of AKI in premature infants was 2.9%.The incidence of AKI was 33.3% (3/9), 3.7% (5/134), and 2.3% (14/620) in the 24-27 + 6 weeks, 28-31 + 6 weeks, and 32-36 + 6 weeks gestational age, respectively, and the difference was statistically significant ( χ2=31.010, P<0.001). Preterm infants in AKI group had a higher proportion of males(77.3% vs. 53.3%), lower gestational weeks[29(27, 33) weeks vs.31(29, 33)weeks], higher proportions of infants with diabetic mothers(40.9% vs.19.4%), lower Apgar scores at 1 and 5 minutes[8(7, 10) vs.9(8, 10), 9(9, 10) vs.10(9, 10), respectively], higher proportions of invasive and noninvasive respiratory support(45.5% vs.11.3%, 63.6% vs.19.2%, respectively), longer duration of invasive respiratory support[260(136, 742)h vs.72(18, 160)h], longer hospital stays[66(19, 88)d vs.42(26, 58)d], and higher rates of sepsis (27.3% vs. 6.5%), respiratory distress syndrome(40.9% vs. 11.6%), and patent ductus arteriosus that requiring ibuprofen or surgical closure(13.6% vs. 3.0%), diuretic(27.3% vs. 3.9%), and vasoactive drug use (22.7% vs. 3.6%) than those in non-AKI group, and the differences were statistically significant(all P<0.05). Multivariate regression analysis showed that sepsis was an independent risk factor for AKI in preterm infants ( P=0.039, OR=3.498, 95% CI 1.065-11.490) after adjustment of gestational age and birth weight. Conclusion:The incidence of AKI is relatively high in preterm infants with gestational age<28 weeks.Compared with preterm infants without AKI, preterm infants with AKI have smaller gestational weeks and longer hospital stay.Sepsis is an independent risk factor for AKI in preterm infants.