Renal Regional Oxygen Saturation and Acute Kidney Injury in Neonates with Perinatal Asphyxia.

Objective:  Neonates with moderate-to-severe perinatal asphyxia often develop acute kidney injury (AKI). Additionally, therapeutic hypothermia (TH) can affect renal blood flow. This study aimed to evaluate the association between renal regional oxygen saturation (rSrO₂) during TH and AKI in neonates with moderate and severe perinatal asphyxia.

Study design:  This retrospective longitudinal study included neonates with moderate-to-severe asphyxia who required TH. The primary outcome was the occurrence of AKI, classified as a rate of decrease in creatinine levels of <33% at 72 hours of TH. rSrO₂ was continuously monitored by near-infrared spectroscopy during the hypothermia and rewarming phases. Data analysis involved dividing the average rSrO₂ levels into 12-hour periods. We analyzed the association between AKI and rSrO₂ levels using univariate and multivariate logistic regression models. Furthermore, we assessed the predictive capacity of rSrO₂ for AKI by analyzing the area under the receiver operating characteristic curve.

Results:  Ninety-one patients were included in the study. On average, patients with AKI exhibit lower rSrO₂ levels during TH. Specifically, rSrO₂ levels within the first 12 hours and between 25 and 72 hours of TH demonstrated the highest predictive capability for AKI. Multivariate logistic regression analysis revealed that rSrO₂ levels within the initial 12 hours (adjusted odds ratio [aOR] = 1.11, 95% confidence interval [CI]: 1.01-1.21) and between 61 and 72 hours (aOR = 0.85, 95% CI: 0.78-0.92) were significantly associated with AKI.

Conclusion:  An increase in rSrO₂ during the first 12 hours of TH and lower rSrO₂ levels between 61 and 72 hours of treatment were associated with the development of AKI in asphyxiated neonates undergoing TH.

Key points: · Neonates with asphyxia often develop AKI.. · Renal saturations are affected by hypothermia and asphyxia. · Patients with AKI initially show higher rSrO2, then lower rSrO2.. · Monitoring rSrO2 identifies early AKI..