735 Acute kidney injury in neonates following post cardiac surgery utilizing the akin definition: A retrospective study

Abstract

Acute kidney injury (AKI) is common in the newborn period, but there is little known about the epidemiology and the incidence of AKI, especially in high-risk groups such as post heart surgery patients. The incidence of AKI in neonates varies widely between 3.4 to 61% based on the use of various AKI definitions. Since the launch of standardized AKI definitions such as AKIN (Acute Kidney Injury Network), there have been no studies applying them to the neonatal population. AKIN criteria consists of three stages: 1 (mild), 2 (moderate), and 3 (severe), which are based on specified changes in serum creatinine and/or urine output. Our objective was to describe the clinical characteristics of neonates with AKI following congenital heart surgery, utilizing the AKIN definition. Retrospective, single center observational design. We included all post heart surgery neonates admitted to PICU at our hospital between January 1st 2006 and May 30th 2009 with AKI as defined by their maximal AKIN stage. Patient data was collected from a PICU database and medical charts. Table 1 describes patients' characteristics. We identified 76 (54% males) out of 122 neonates who underwent heart surgery and developed AKI over the study period. Overall, the mean age was 8.4 ± 7.6 days with 90% of them being term gestation. However, younger patients were observed in AKIN stage 3 with a mean age of 6.03 ± 5.37 days. Twenty two (29%) patients had closed heart and 54 (71%) had open heart surgical procedures. AKIN stage 3 patients underwent mostly open heart procedures (82.9%). Twenty-six (34%) had Risk Adjustment in Congenital Heart Surgery-1 score > 3. Most of these patients (69%) were in AKIN stage 3. Regarding cardiac diagnosis, majority of patients had transposition of the great arteries (39.5%). The overall incidence of AKI was 62%. AKI occurred early as 57 of 76 neonates reached their maximal AKIN stage within 24 hours following surgery (Figure1). Eleven neonates died after AKI, 8 were after open heart (72%) and 9 within the first 10 days post AKI. All deaths occurred in AKIN stage 3.Tabled 1View Large Image Figure ViewerDownload Hi-res image Download (PPT) AKI is common in post-heart surgery neonates. Our incidence of 62% is high, but is explained in part by the sensitivity of the AKIN definition. AKI occurs early in the post-operative course with an overall mortality of 14.5%. All deaths occurred with AKIN stage 3. Open heart surgery and younger age showed a trend of increased mortality.