The Relationship Between Electrocerebral Activity and Cerebral Fractional Tissue Oxygen Extraction in Preterm Infants

Abstract

Impaired cerebral oxygen delivery may cause cerebral damage in preterm infants. At lower levels of cerebral perfusion and oxygen concentration, electrocerebral activity is disturbed. The balance between cerebral oxygen delivery and oxygen use can be measured by near-infrared spectroscopy (NIRS), and electrocerebral activity can be measured by amplitude-integrated EEG (aEEG). Our aim was to determine the relationship between regional cerebral tissue oxygen saturation (r c SO 2 ), fractional tissue oxygen extraction (FTOE), and aEEG. We recorded longitudinal digital aEEG and r c SO 2 prospectively in 46 preterm infants (mean GA 29.5 wk, SD 1.7) for 2 hr on the 1st to 5th, 8th, and 15th d after birth. We excluded infants with germinal matrix hemorrhage exceeding grade I and recordings of infants receiving inotropes. FTOE was calculated using transcutaneous arterial oxygen saturation (tcSaO 2 ) and r c SO 2 values: (tcSaO 2 Ϫ r c SO 2 )/tcSaO 2 . aEEG was assessed by calculating the mean values of the 5th, 50th, and 95th centiles of the aEEG amplitudes. The aEEG amplitude centiles changed with increasing GA. FTOE and aEEG amplitude centiles increased significantly with postnatal age. More mature electrocerebral activity was accompanied by increased FTOE. FTOE also increased with increasing postnatal age and decreasing Hb levels. (Pediatr Res 70: 384-388, 2011)

Quiescent variability of cerebral, renal, and splanchnic regional tissue oxygenation in very low birth weight neonates

“…Several investigators argue that a lack of normative data [30,31], and similar lack of uniformity in rSO 2 averaging techniques, with monitoring epochs ranging from 5 to 120 minutes across various studies [5,8,10,13,16,17,20,32], currently hinder the use of NIRS as a standard monitoring tool in VLBW neonates. Given the results of our analysis, we recommend 5-15 minutes as a preferred data averaging interval for RrSO 2 and SrSO 2 measurements in order to establish a baseline signal for eventual clinical trend monitoring.…”

“…Cerebral rSO 2 (CrSO 2 ) is used as an adjunct to amplitude-integrated electroencephalography in gauging injury in asphyxiated newborns [4][5][6]. While some use of short-term rSO 2 trending exists, expanded use of NIRS monitoring in the neonatal intensive care unit (NICU) has been hindered by a paucity of normative data in stable patients.…”

Amplitude-Integrated EEG and Cerebral Near-Infrared Spectroscopy in Cooled, Asphyxiated Infants

“…1 Even though NIRS was previously not thought to contribute to the predictive value of aEEG, our study adds to the evidence that possibly the use of cerebral NIRS has the added clinical advantage of predicting outcome. 12,13,27,[30][31][32][33] Our study has some limitations. We have a small sample size, similar as in other studies.…”

Simultaneous Near-Infrared Spectroscopy (NIRS) and Amplitude-Integrated Electroencephalography (aEEG): Dual Use of Brain Monitoring Techniques Improves Our Understanding of Physiology

“…This suggested that higher extraction of oxygen is needed to support brain metabolism. Ter Horst et al (6) investigated the relationship between rScO 2 , cFTOE and aEEG measures in 46 preterm infants. aEEG amplitude changed with increasing gestational age while cFTOE and aEEG amplitude also increased with postnatal age.…”