Severe Intraventricular Hemorrhage in Extremely Premature Infants: Are high Carbon Dioxide Pressure or Fluctuations the Culprit?

OBJECTIVE: This study aims to examine the association between measures of hypercapnia and fluctuation in Pco 2 and severe intraventricular hemorrhage (IVH) and to evaluate the prevalence of hypercapnia, hypocapnia, and fluctuations in Pco 2 in the initial 72 hours of life among premature infants.

STUDY DESIGN: Retrospective study of premature infants with birth weight < 1,250 g, who were receiving some respiratory support. All blood gases obtained in the first 3 days of life were collected. Univariate and multivariate analyses were performed to assess the association of hypercapnia, and fluctuations in Pco 2 with severe IVH.

RESULT: Our cohort included 285 patients, of whom 84% were intubated. Only 20% patients had all blood gases in the normocapnia range; 9% had at least 1 gas with hypercapnia; 51% had at least 1 gas with hypocapnia, and 20% patients had both hypercapnia and hypocapnia at different times. Infants with severe IVH (n = 41) had significantly higher peak Pco 2 and greater fluctuations in Pco 2 within a short interval, compared with those without severe IVH (n = 227). After controlling for gestational age, gender, antenatal steroid exposure, presence of hypercapnia, and Apgar score at 5 minutes, fluctuation in Pco 2 remained significantly associated with severe IVH.

CONCLUSION: Fluctuations in Pco 2 within a short period may be more significantly associated with severe IVH than the mere presence of hypercapnia.