Capillary partial pressure of carbon dioxide for predicting rehospitalization in preterm infants under noninvasive respiratory support with severe bronchopulmonary dysplasia

Background The severity of bronchopulmonary dysplasia (BPD) is an important predictor of prognosis in preterm infants. However, the severity of BPD was determined mainly by the degree of oxygen supplementation and mode of respiratory support. Objectives This retrospective study aimed to examine the role of partial pressure of carbon dioxide (pCO(2)) in predicting rehospitalization among preterm infants with severe BPD without invasive ventilation at 36 weeks' postmenstrual age (PMA). Methods We assessed preterm infants aged <32 gestational weeks with severe BPD who were receiving noninvasive respiratory support at 36 weeks' PMA. Patients were compared after stratifying them according to the history of rehospitalization owing to respiratory infection before a corrected age (CA) of 1 year and pCO(2) measured by capillary blood gas analysis at 36 weeks' PMA. Results Among 54 infants who had severe BPD with noninvasive respiratory support at 36 weeks' PMA, 16 (29.6%) experienced rehospitalization due to respiratory problems. At 36 weeks' PMA, the amount of oxygen supplementation (0.30 vs. 0.28, p = 0.021) and pCO(2) (62.1 vs. 53.6 mmHg, p = 0.006) were higher in the rehospitalization group than in the no rehospitalization group. Multivariate logistic analysis findings indicated that pCO(2) >= 57.4 mmHg was the only factor associated with rehospitalization (adjusted odds ratio: 8.017, 95% confidence interval 1.239-51.859). Conclusion High pCO(2) during noninvasive respiratory support at 36 weeks' PMA in severe BPD was associated with rehospitalization. Consideration of the degree of impairment in ventilatory capacity may improve the prediction of later respiratory outcomes in infants with BPD.