Prevalence of Acute Kidney Injury and Its Risk Factors for Severity in Neonates With Suspected Sepsis at Kenyatta National Hospital

Abstract

Background Acute Kidney Injury (AKI) is characterized by a sudden decline in renal function resulting in the inability of the kidneys to excrete nitrogenous wastes. The criteria for neonatal AKI vary among different studies. Serum creatinine levels of 1.5mg /dl have been used as cut off levels for AKI case definition (1). The causes of neonatal AKI can be prerenal, renal and post-renal; however prerenal azotemia is the most common type of AKI found in the neonates (85%) (2). The WHO global observatory has neonatal sepsis amongst the leading causes of neonatal mortality accounting for 400,000 neonatal deaths globally per annum (3). Sepsis is often complicated by multiple organ dysfunctions and due to the unique aspects of neonatal renal physiology; acute kidney injury (AKI) often complicates sepsis. Objectives The primary objective was to determine the prevalence of acute kidney injury in neonates with suspected sepsis admitted at Kenyatta National Hospital. Our secondary objective was to determine the neonatal and maternal factors that are associated with AKI severity in the study population.Sepsis is a common cause of morbidity in neonates, establishing its association with AKI was intended to drive a high index of suspicion and facilitate prompt diagnosis and treatment to improve neonatal outcomes. Methods We carried out a hospital based cross-sectional study in which neonates admitted with suspected sepsis were evaluated for AKI by measuring their serum creatinine levels. Neonates with a serum creatinine of 100μmmols/l or more were considered to have AKI. We monitored the neonates urine output for 24hrs, and also administered questionnaires to the mothers who had consented to the study and whose neonates had met the inclusion criteria. Data on the risk factors were obtained and subsequently we classified AKI severity by the neonatal RIFLE criteria. Data was analyzed using (SPSS) version 21.Chi square tests were conducted to analyze the relationship between the dependent and the independent variables. ANOVA was used for linear data. vi Results There were 352 newborns admitted to the KNH paediatric wards during the study period, of these, 332 newborns met the clinical criteria for the diagnosis of suspected sepsis and of these 120 cases of acute kidney injury were found, yielding a prevalence of 36.1% (95% CI 31 to 41.6). The most common AKI presentation based on the neonatal RIFLE criteria was Failure at 72 (62.6%, 95% CI 53.6 to 71.6), followed by Injury 26 (22.6%;95% CI 14.8 to 30.4). There were 17 (14.8%; 95% CI 8.2 to 21.3) newborns classified as Risk. The 24 hour urine output per kilogram body weight was 1.8 ± 1.1. Serum creatinine levels ranged from 188 to 1027μmol/l with a mean of 393.3±200.5. Based on the neonatal characteristics versus the AKI risk, there was a significant association between AKI and age of neonate (ANOVA p=0.04). Neonates classified as having AKI risk were on average aged 8.3 days compared to those with injury (mean=12.8 days±7.1) and those in failure (mean =12.2days ± 5.2 days). The post hoc analysis showed that the difference in age between the neonates at risk and those with injury was statistically significant (Bonferroni P =0.035) while that between injury and failure or risk and failure was not significant. The mean gestational age (p = 0.823) and birth weight (p =0.767) were not associated with AKI. The maternal demographics that had significant association with AKI were maternal fever in the week preceding delivery and the presence of a post-partum complication of either puerperal sepsis or post-partum hemorrhage at p=0.041 and p=0.038 respectively. All the other maternal socio-demographic and labor related factors had no significant association with AKI. Conclusion The prevalence of AKI among neonates with suspected sepsis was 36.1%.Neonates with late onset sepsis were more likely to develop AKI than those with early onset sepsis. The presence of maternal fever in the week preceding delivery and post-partum complications were associated with severe form of AKI in the neonates.