Predictors of home oxygen duration in chronic neonatal lung disease

Abstract

Aims: The primary aim was to identify predictors of home oxygen duration for preterm infants with chronic neonatal lung disease (CNLD). Secondary aims were to identify predictors of oxygen flow rates at discharge and the association of discharge oxygen flow rates with respiratory outcomes. Methods: Retrospective cohort of infants with CNLD requiring home oxygen in 2016 and 2017. Hazard ratios (HR) were estimated from Cox proportional hazards regression models in the entire cohort. Multiple linear regression models were used to examine the effects of maternal and infant variables and the effect of post-discharge factors on oxygen flow rate. Results: Home oxygen ceased in 149 infants at a median postmenstrual age (PMA) of 6.8 months (IQR 4.4) with 87.2% of infants weaned by 12 months. Shorter neonatal hospitalization predicted faster oxygen weaning at 9 months (HR 0.99, 95% CI 0.98-1.00, p=0.02) and 12 months (HR 0.99, 95% CI 0.98-1.00, p=0.02) PMA. Each mmHg increase in carbon dioxide partial pressure at term was associated with 4.99 mL/min more home oxygen (95% CI, 1.45-8.52, p=0.01). Infants born at a tertiary neonatal intensive care required 63.42mL/min more oxygen (95% CI, 2.03-124.82, p=0.04). Pulmonary hypertension and respiratory related hospital admission were associated with 139.83 mL/min (95% CI 12.56-267.10, p=0.03) and 18.40 mL/min (95% CI, 1.98-34.81, p=0.03) more home oxygen respectively. Conclusion: The best predictor of oxygen duration is length of neonatal hospital stay. Care should be taken to ensure infants with moderate to severe hypercapnia or pulmonary hypertension have adequate oxygen flow rates at discharge.