Blood Carbon Dioxide Levels and Adverse Outcome in Neonatal Hypoxic-Ischemic Encephalopathy

 

 Buy Article Permissions and Reprints

ABSTRACT

We investigated pCO₂ patterns and the relationship between pCO₂ 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 (pCO₂ <3.3 kPa), severe hypocapnia (pCO₂ <2.6 kPa), and hypercapnia (pCO₂ >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) pCO₂ 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.

REFERENCES

• 1 Robertson C M, Finer N N, Grace M G. School performance of survivors of neonatal encephalopathy associated with birth asphyxia at term.  J Pediatr. 1989;  114 753-760
  CrossrefPubMedGoogle Scholar
• 2 Vannucci R C. Hypoxic-ischemic encephalopathy.  Am J Perinatol. 2000;  17 113-120
  Article in Thieme ConnectPubMedGoogle Scholar
• 3 Ito H, Ibaraki M, Kanno I, Fukuda H, Miura S. Changes in the arterial fraction of human cerebral blood volume during hypercapnia and hypocapnia measured by positron emission tomography.  J Cereb Blood Flow Metab. 2005;  25 852-857
  CrossrefPubMedGoogle Scholar
• 4 Murase M, Ishida A. Early hypocarbia of preterm infants: its relationship to periventricular leukomalacia and cerebral palsy, and its perinatal risk factors.  Acta Paediatr. 2005;  94 85-91
  CrossrefPubMedGoogle Scholar
• 5 Fabres J, Carlo W A, Phillips V, Howard G, Ambalavanan N. Both extremes of arterial carbon dioxide pressure and the magnitude of fluctuations in arterial carbon dioxide pressure are associated with severe intraventricular hemorrhage in preterm infants.  Pediatrics. 2007;  119 299-305
  CrossrefPubMedGoogle Scholar
• 6 Klinger G, Beyene J, Shah P, Perlman M. Do hyperoxaemia and hypocapnia add to the risk of brain injury after intrapartum asphyxia?.  Arch Dis Child Fetal Neonatal Ed. 2005;  90 F49-F52
  CrossrefPubMedGoogle Scholar
• 7 Fritz K I, Ashraf Q M, Mishra O P, Delivoria-Papadopoulos M. Effect of moderate hypocapnic ventilation on nuclear DNA fragmentation and energy metabolism in the cerebral cortex of newborn piglets.  Pediatr Res. 2001;  50 586-589
  CrossrefPubMedGoogle Scholar
• 8 Lasso Pirot A, Fritz K I, Ashraf Q M, Mishra O P, Delivoria-Papadopoulos M. Effects of severe hypocapnia on expression of bax and bcl-2 proteins, DNA fragmentation, and membrane peroxidation products in cerebral cortical mitochondria of newborn piglets.  Neonatology. 2007;  91 20-27
  CrossrefPubMedGoogle Scholar
• 9 Fritz K I, Zubrow A, Mishra O P, Delivoria-Papadopoulos M. Hypercapnia-induced modifications of neuronal function in the cerebral cortex of newborn piglets.  Pediatr Res. 2005;  57 299-304
  CrossrefPubMedGoogle Scholar
• 10 Kaiser J R, Gauss C H, Pont M M, Williams D K. Hypercapnia during the first 3 days of life is associated with severe intraventricular hemorrhage in very low birth weight infants.  J Perinatol. 2006;  26 279-285
  CrossrefPubMedGoogle Scholar
• 11 Yildizdaş D, Yapicioğlu H, Yilmaz H L, Sertdemir Y. Correlation of simultaneously obtained capillary, venous, and arterial blood gases of patients in a paediatric intensive care unit.  Arch Dis Child. 2004;  89 176-180
  CrossrefPubMedGoogle Scholar
• 12 Johnson K J, Cress G A, Connolly N W, Burmeister L F, Widness J A. Neonatal laboratory blood sampling: comparison of results from arterial catheters with those from an automated capillary device.  Neonatal Netw. 2000;  19 27-34
  PubMedGoogle Scholar
• 13 Barnett A L, Guzzetta A, Mercuri E et al.. Can the Griffiths scales predict neuromotor and perceptual-motor impairment in term infants with neonatal encephalopathy?.  Arch Dis Child. 2004;  89 637-643
  CrossrefPubMedGoogle Scholar
• 14 Fritz K I, Zubrow A B, Ashraf Q M, Mishra O P, Delivoria-Papadopoulos M. The effect of hypocapnia (PaCO2 27 mmHg) on CaM kinase IV activity, Bax/Bcl-2 protein expression and DNA fragmentation in the cerebral cortex of newborn piglets.  Neurosci Lett. 2003;  352 211-215
  CrossrefPubMedGoogle Scholar
• 15 Broccard A F, Hotchkiss J R, Vannay C et al.. Protective effects of hypercapnic acidosis on ventilator-induced lung injury.  Am J Respir Crit Care Med. 2001;  164 802-806
  PubMedGoogle Scholar
• 16 Duncan A. Paediatric Intensive Care. London; BMJ Books 1998
  PubMedGoogle Scholar
• 17 Shankaran S, Pappas A, Laptook A R NICHD Neonatal Research Network et al.. Outcomes of safety and effectiveness in a multicenter randomized, controlled trial of whole-body hypothermia for neonatal hypoxic-ischemic encephalopathy.  Pediatrics. 2008;  122 e791-e798
  CrossrefPubMedGoogle Scholar
• 18 Gluckman P D, Gunn A J, Wyatt J S. Hypothermia for neonates with hypoxic-ischemic encephalopathy.  N Engl J Med. 2006;  354 1643-1645 author reply 1643-1645
  CrossrefPubMedGoogle Scholar
• 19 Wyatt J S, Gluckman P D, Liu P Y CoolCap Study Group et al.. Determinants of outcomes after head cooling for neonatal encephalopathy.  Pediatrics. 2007;  119 912-921
  CrossrefPubMedGoogle Scholar

Professor Tony Ryan

NICU, Cork University Maternity Hospital

Wilton, Cork, Ireland

Email: tonyryan007@gmail.com