Recognition and reporting of AKI in very low birth weight infants

Abstract

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.

Keywords: CKD; acute renal failure; pediatrics.

Figure 1.

Identification, exclusion, and analysis of infants for the study.

Figure 2.

AKI occurrence by gestational age among very low birth weight infants; 80% of infants who experienced AKI were born at <28 weeks gestational age, whereas 73% of infants who did not experience AKI were born at ≥28 weeks gestational age (odds ratio, 10.6; 95% confidence interval, 6.8 to 16.7; c statistic=0.76; 95% confidence interval, 0.72 to 0.81).