Re-examining the arterial cord blood gas pH screening criteria in neonatal encephalopathy

Arch Dis Child Fetal Neonatal Ed. 2018 Jul;103(4):F377-F382. doi: 10.1136/archdischild-2017-313078. Epub 2017 Sep 23.

Abstract

Objective: Screening criteria for neonatal encephalopathy remain a complex combination of subjective and objective criteria. We examine the utility of universal cord blood gas testing and mandatory encephalopathy evaluation for infants with pH ≤7.10 on umbilical cord arterial blood gas (cABG) as a single screening measure for timely identification of moderate/severe encephalopathy.

Design, setting, patients: Infants born at a single centre between 2008 and 2015, who were ≥36 weeks, had no congenital anomalies and had a cABG pH ≤7.10 were identified for a retrospective cohort study. Maternal/perinatal and patient factors were collected.

Results: 27 028 infants were born during the study period; 412 met all inclusion criteria. Of those, 35/85 infants with pH <7.00 and 34/327 infants with pH between 7.00 and 7.10 had moderate/severe encephalopathy. Encephalopathy was identified on the basis of pH and examination alone (no other perinatal criteria present) in 5/35 and 13/34 infants in the two pH groups, respectively.A cABG pH threshold of ≤7.10 was associated with a sensitivity of 74.2% and a specificity of 98.7% for detection of moderate/severe encephalopathy. Based on these data, 25 infants with cABG pH between 7.00 and 7.10 will need to be screened to identify one neonate with moderate/severe encephalopathy, who might have otherwise been missed using conventional screening, a 15% increase in appropriate selection and treatment over current methods.

Conclusion: Universal cord blood gas screening with a pH threshold ≤7.10 and mandatory encephalopathy examination results in greater detection of infants with moderate/severe encephalopathy and timely initiation of therapeutic hypothermia.

Keywords: neonatology; neurology.

MeSH terms

  • Blood Gas Analysis / methods*
  • Brain Diseases / blood
  • Brain Diseases / diagnosis*
  • Female
  • Fetal Blood / chemistry*
  • Humans
  • Hydrogen-Ion Concentration*
  • Infant, Newborn
  • Male
  • Neonatal Screening / methods*
  • Retrospective Studies
  • Umbilical Arteries*