title: Blood carbon dioxide levels and adverse outcome in neonatal hypoxic-ischemic encephalopathy.
abstract: We investigated pCO(2) patterns and the relationship between pCO(2) levels and neurodevelopmental outcome in term infants with hypoxic-ischemic encephalopathy. Blood gases during the first 72 hours of life were collected from 52 infants with hypoxic-ischemic encephalopathy. Moderate hypocapnia (pCO(2) <3.3 kPa), severe hypocapnia (pCO(2) <2.6 kPa), and hypercapnia (pCO(2) >6.6 kPa) were correlated to neurodevelopmental outcome at 24 months. Normocapnia was documented in 416/551 (75.5%) of samples and was present during the entire 72 hours in only 6 out of 52 infants. Mean (standard deviation) pCO(2) values did not differ between infants with normal and abnormal outcomes: 5.43 (2.4) and 5.41 (2.03), respectively. There was no significant association between moderate hypocapnia, severe hypocapnia, or hypercapnia and adverse outcome (odds ratio [OR] = 1.84, 95% confidence interval [CI] = 0.49 to 6.89; OR = 3.16, CI = 0.14 to 28.45; and OR = 1.07, CI = 0.24 to 5.45, respectively). In conclusion, only one in nine newborns had normocapnia throughout the first 72 hours. Severe hypocapnia was rare and occurred only in ventilated babies. Hypercapnia and hypocapnia in infants with hypoxic-ischemic encephalopathy during the first 72 hours of life were not associated with adverse outcome.
authors.affiliation: Neonatal Intensive Care Unit, Cork University Maternity Hospital, Cork, Ireland.
authors.forename: Montasser
authors.initials: M
authors.lastname: Nadeem
authors.forename: Deirdre
authors.initials: D
authors.lastname: Murray
authors.forename: Geraldine
authors.initials: G
authors.lastname: Boylan
authors.forename: Eugene M
authors.initials: EM
authors.lastname: Dempsey
authors.forename: C Anthony
authors.initials: CA
authors.lastname: Ryan
mesh_terms: D002245:Carbon Dioxide / Q000009:adverse effects* / Q000097:blood*; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000097:blood; D016857:Hypocapnia / Q000097:blood; D020925:Hypoxia-Ischemia, Brain / Q000097:blood*; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications; D011256:Pregnancy Outcome
chemical_list: D002245:Carbon Dioxide