Transcutaneous carbon dioxide monitoring during therapeutic hypothermia for neonatal encephalopathy

Abstract

BACKGROUND:In neonates with post-asphyxial neonatal encephalopathy, further neuronal damage is prevented with therapeutic hypothermia (TH). In addition, fluctuations in carbon dioxide levels have been associated with poor neurodevelopmental outcome, demanding close monitoring. This study investigated the accuracy and clinical value of transcutaneous carbon dioxide (tcPCO 2 ) monitoring during TH. METHODS: In this retrospective cohort study in neonates, agreement between arterial carbon dioxide (PaCO 2 ) values and tcPCO 2 measurements during TH was determined. TcPCO 2 levels during the first 24 h of hypothermia were tested for an association with ischemic brain injury on magnetic resonance imaging (MRI). RESULTS: Thirty-four neonates were included. Agreement (bias (95% limits of agreement)) between tcPCO 2 and PaCO 2 levels was 3.9 (−12.4-20.2) mm Hg. No relation was found between the body temperature and tcPCO 2 levels. TcPCO 2 levels differed significantly between patients with considerable and minimal damage on MRI; after 6 h (P = 0.02) and 9 h (P = 0.04). CONCLUSIONS: Although tcPCO 2 provided a limited estimation of PaCO 2 , it can be used for trend monitoring during TH. TcPCO 2 levels after birth could provide an early indicator of ischemic brain injury. This relation should be investigated in large prospective studies, in which adjustments for confounders can be made.