Influence of PCO 2 Control on Clinical and Neurodevelopmental Outcomes of Extremely Low Birth Weight Infants

摘要

Background: Levels or fluctuations in the partial pressure of CO_(2)(PCO_(2)) may affect outcomes for extremely low birth weight infants. Objectives: In an exploratory analysis of a randomized trial, we hypothesized that the PCO_(2)values achieved could be related to significant outcomes. Methods: On each treatment day, infants were divided into 4 groups: relative hypocapnia, normocapnia, hypercapnia, or fluctuating PCO_(2). Ultimate assignment to a group for the purpose of this analysis was made according to the group in which an infant spent the most days. Statistical analyses were performed with analysis of variance (ANOVA), the Kruskal-Wallis test, the χ~(2)test, and the Fisher exact test as well as by multiple logistic regression. Results: Of the 359 infants, 57 were classified as hypocapnic, 230 as normocapnic, 70 as hypercapnic, and 2 as fluctuating PCO_(2). Hypercapnic infants had a higher average product of mean airway pressure and fraction of inspired oxygen (MAP × FiO_(2)). For this group, mortality was higher, as was the likelihood of having moderate/severe bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), and poorer neurodevelopment. Multiple logistic regression analyses showed an increased risk for BPD or death associated with birth weight ( p p p p Conclusions: Birth weight and respiratory morbidity, as measured by MAP × FiO_(2), were the most predictive of death or BPD and NEC, whereas poor neurodevelopmental outcome was associated with low birth weight and IVH. Univariate models also identified PCO_(2). Thus, hypercapnia seems to reflect greater disease severity, a likely contributor to differences in outcomes.