Non-Invasive Respiratory Severity Indices Predict Adverse Outcomes in Bronchopulmonary Dysplasia

Objective To test the hypothesis that elevated respiratory severity indices will identify patients with severe bronchopulmonary dysplasia (BPD) at the highest risk for adverse in-hospital outcomes. Study design Retrospective cohort study. A modified respiratory severity score (mean airway pressure x FiO2) and a modified pulmonary score (respiratory support score x FiO2 + sum of medication scores) were calculated in a consecutive cohort of patients ≥36 weeks post-menstrual age with severe BPD admitted to a referral center between 2010-2018. The association between each score and the primary composite outcome of death/prolonged length of stay (>75th percentile for cohort) was assessed using area under the receiver operator characteristic curve (AUROC) analysis and logistic regression. Death and the composite outcome death/tracheostomy were analyzed as secondary outcomes. Results In 303 patients, elevated scores were significantly associated with increased adjusted odds of death/prolonged length of stay: aOR 1.5 (95% CI 1.3-1.7) for the modified respiratory severity score and aOR 11.5 (95% CI 5.5-24.1) for the modified pulmonary score. The modified pulmonary score had slightly better discrimination of death/prolonged length of stay when compared with the modified respiratory severity score, AUROC 0.90 (95% CI 0.85-0.94) vs 0.88 (95% CI 0.84-0.93), P= 0.03. AUROCs for death and death/tracheostomy did not differ significantly when comparing the modified respiratory severity score with the modified pulmonary score. Conclusions In our referral center, the modified respiratory severity score or the modified pulmonary score identified patients with established severe BPD at the highest risk for death/prolonged length of stay, death, and death/tracheostomy.