The incidence of acute kidney injury in very-low-birth-weight infants treated early with caffeine

Acute kidney injury (AKI) in neonates is associated with increased morbidity and mortality, longer hospitalization, and a higher risk for future kidney damage. Caffeine treatment has reportedly been associated with a decreased AKI occurrence. However, previous studies lack uniformity regarding dosage and timing of administration. This study aimed to assess AKI incidence in very-low-birth-weight (VLBW) preterm infants (< 1500 g) treated with early high-dose caffeine and to identify risk factors associated with AKI.

A retrospective cohort study of VLBW preterm infants admitted to the Neonatal Intensive Care Unit at the Shaare Zedek Medical Center between January 1, 2017, and December 31, 2019. All VLBW infants born < 32 weeks of gestation were treated with a standardized caffeine regimen (20 mg/kg bolus; in the first hour of life, maintenance 10 mg/kg/day). Maternal and infant data including clinical, demographic, and laboratory measurements were retrieved from electronic medical records.

Of 311 VLBW infants admitted, all had adequate serum creatinine and urine output data. Of 301 patients included for analysis, 41 (14%) were diagnosed with AKI, while only 12/301 (4%) were diagnosed during the first week of life. Sixteen infants (5%) had > 1 AKI episode. Seven (7/41, 17%) had AKI stage 1 and seventeen infants (17/41, 42%) had stages 2 and 3. In univariate analysis, sepsis, patent ductus arteriosus, necrotizing enterocolitis (NEC), and hemodynamic instability during the first week of life were more prevalent in the AKI group. Infants with AKI were born with lower birth weights, at earlier gestational weeks, and had lower APGAR and higher CRIB II scores. NEC was the only significant risk factor associated with AKI in multivariate analysis. They also had a higher risk for bronchopulmonary dysplasia (BPD), longer hospitalization, and higher mortality rate.

The incidence of AKI in a cohort of VLBW infants universally treated early with caffeine was 14%, while only 4% had AKI during the first week. Infants with AKI had worse outcomes (BPD and mortality) and longer hospitalization.