Jonathan R. Swanson

BACKGROUND AND OBJECTIVES: AKI is associated with both increased short-term morbidity and mortality and greater long-term risk for CKD. This study determined the prevalence of AKI among very low birth weight infants using a modern study definition, evaluated the frequency of AKI diagnosis reporting in the discharge summary, and determined whether infants were referred to a pediatric nephrologist for AKI follow-up. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Records of very low birth weight infants admitted to a level IV neonatal intensive care unit from 2008 to 2011 were reviewed. AKI was classified using the Kidney Disease: Improving Global Outcomes definition modified to include only serum creatinine. RESULTS: AKI occurred in 39.8% of 455 infants; 75 (16.5%) infants experienced multiple episodes of AKI, and 8 (2%) infants were discharged with an abnormal last creatinine. Updated clinical risk index for babies score >10 (odds ratio, 12.9; 95% confidence interval, 7.8 to 21.4) and gestational age <28 weeks (odds ratio, 10.6; 95% confidence interval, 6.8 to 16.7) were strongly associated with AKI in univariate analyses. AKI was associated with increased mortality (odds ratio, 4.0; 95% confidence interval, 1.4 to 11.5) and length of stay (11.7 hospital days; 95% confidence interval, 5.1 to 18.4), even after accounting for gestational age, birth weight, and updated clinical risk index for babies score. AKI was recorded in the discharge summary for only 13.5% of AKI survivors. No infants were referred to a nephrologist for AKI follow-up. CONCLUSIONS: AKI occurred in 40% of very low birth weight infants and was concentrated in the most premature and severely ill infants. One in six infants experienced multiple episodes of AKI, and a small number of infants was discharged with an elevated serum creatinine. Reporting a history of AKI in the discharge summary occurred infrequently, and referral to a nephrologist for AKI follow-up did not occur, highlighting areas for quality improvement.

OBJECTIVE: To quantify exposure to potentially nephrotoxic medications among very low birth weight (VLBW) infants and determine the relationship of nephrotoxic medication exposure to acute kidney injury (AKI) in this vulnerable population. METHODS: We reviewed 107 VLBW infants who survived to discharge from April 2011 to March 2012 and measured exposure to the following nephrotoxic medications: acyclovir, amikacin, amphotericin B, gentamicin, ibuprofen, indomethacin, iohexol, tobramycin and vancomycin. Acute kidney injury was determined by the KDIGO guidelines. RESULTS: Exposure to ≥ 1 nephrotoxic medication occurred in 87% of infants. The most common exposures were gentamicin (86%), indomethacin (43%) and vancomycin (25%). There was an inverse linear relationship between birth weight and nephrotoxic medications received per day (R(2) = 0.169, p < 0.001). Infants with AKI received more nephrotoxic medications per day than those who did not (0.24 versus 0.15; p = 0.003). CONCLUSIONS: VLBW infants are frequently exposed to nephrotoxic medications, receiving approximately two weeks of nephrotoxic medications before discharge or 1 for every 6 d of hospitalization. The greatest exposure occurred among the smallest, most immature infants and those who experienced AKI.