Association between impaired renal function based on decline in serum creatinine level and brain injury in neonates with hypoxic-ischemic encephalopathy

BACKGROUND: Impaired renal function (IRF), defined as the rate of decline in serum creatinine levels during the week after birth, frequently affects neonates with moderate or severe hypoxic-ischemic encephalopathy (HIE). However, its clinical relevance in this vulnerable population requires further investigation. PURPOSE: This study aimed to evaluate the association between IRF and brain injury severity in neonates with HIE. METHODS: This retrospective single-center study included neonates treated with therapeutic hypothermia for moderate or severe HIE. A multivariable logistic regression analysis evaluated the association between IRF and the combined outcomes of early death or severe brain injury (ED/SevereBI). RESULTS: Of the 147 included neonates, 67 (45.6%) had IRF and 32 (22%) had ED/SevereBI. Those with ED/SevereBI were more likely to have a lower 5-min Apgar score (median [interquartile range]: 4 [2-5] vs. 2 [1-3], P<0.01), have a higher initial blood lactate level (mean cord blood lactate level, +34%, P<0.05), be intubated in the delivery room (50% vs. 75%, P=0.01), and have IRF (39% vs. 69%, P<0.01). After the adjustment for neonatal characteristics and perinatal asphyxia parameters, neonates with IRF had a 2- to 3-fold higher odds of ED/SevereBI than those without IRF (adjusted odds ratio [95% confidence interval]: 2.66 [1.09-6.84], P=0.03). CONCLUSION: In neonates treated with therapeutic hypothermia for HIE, IRF can be used as a marker of adverse outcomes. Further studies are required to evaluate its long-term prognostic value.