P2C308: Early Acute Kidney Injury Is Not Associated with Development of Pulmonary Artery Hypertension in Very Low Birth Weight Premature Infants with Bronchopulmonary Dysplasia

Background: Acute kidney injury (AKI) has been increasingly recognized as a common systemic inflammatory insult causing long-term morbidity and mortality in premature infants including bronchopulmonary dysplasia (BPD). Such effect of AKI on lungs is mainly due to alteration in fluid homeostasis and electrolyte balance. It is not clearly established if early AKI damages developing lung architecture leading to long-term pulmonary artery hypertension (PAH) associated with BPD.

Methods: We performed a retrospective cohort study including 105 VLBW premature infants who were born at < 32 weeks gestational age (GA) and developed BPD (oxygen requirement at 28 days of life or 36 weeks corrected GA [CGA]), or died before 36 weeks CGA. Outcomes were compared between those with and without early AKI (rise in serum creatinine [SCr] >0.3 mg/dl in 48 hours, or increase in SCr of >150% from baseline, or urine output < 0.5ml/kg/hr for 6 hours in the first 2 weeks of life).

Results: Of 105 VLBW infants with BPD or death, 60 (57%) had early AKI. Infants with BPD or death who suffered from early AKI were more premature (25.2 ± 1.8 weeks vs. 26.9 ± 1.8, p< 0.001), had lower birth weight (747 ± 226 vs 875 ± 240 grams, p=0.006) and lower 5-minute APGAR scores (6 vs 7, p=0.032), were sicker requiring invasive mechanical ventilation (98.3% vs. 88.9%, p=0.039), required arterial line placement (70% vs. 44.4%, p=0.008) and vasopressors (56.7% vs. 20%, p< 0.001). The infants with BPD who had early AKI were more likely to have PAH or death (33.3 vs. 13.3%, p= 0.019). Among surviving infants, length of hospital stay was longer in infants with early AKI (median (IQR): 125 (105-150) vs. 110 (82-126), p=0.039). However, when corrected for covariates, the association between early AKI and PAH or death was not statistically significant (OR: 2.74, 95% CI: 0.542-13.81, p=0.223).

Conclusion: AKI is not associated with development of PAH in premature infants with BPD. However, our study was limited by sample size and therefore, warrants larger prospective studies to confirm these findings.