Cerebral oxygenation in preterm infants receiving transfusion

The influence of severity of anemia and cardiac output (CO) on cerebral oxygenation (CrSO ) and on the change in CrSO following packed red blood cell (PRBC) transfusion in preterm infants has not been evaluated. The objectives of the current study were to evaluate the effect of pre-transfusion hemoglobin (Hb) and CO-weighted oxygen delivery index (ODI) on CrSO and on the post-transfusion CrSO change. Preterm infants of <32 weeks gestational age (GA) receiving PRBC transfusion were enrolled. Infants received 15 ml/kg PRBC over 3 h. CrSO by near-infrared spectroscopy and CO by electrical velocimetry were recorded for 1 h pre-ransfusion and post transfusion. ODI was defined as pre-transfusion Hb × CO. Thirty infants of 26.6 ± 2.0 weeks GA were studied at 19 ± 12 days. Pre-transfusion Hb was 9.8 ± 0.6 g/dl. Pre-transfusion CrSO correlated with pre-transfusion ODI (R  = 0.1528, p = .044) but not with Hb level. The pre-transfusion to post-transfusion CrSO change correlated with pre-transfusion ODI (R  = 0.1764, p = .029) but not with Hb level. CrSO increased from 66 ± 6% to 72 ± 7% post transfusion (p < .001), while arterial oxygen saturation, heart rate, and CO did not change. In these infants, the pre-transfusion ODI was a better indicator of brain oxygenation and its improvement post transfusion than Hb alone. The role of CO and tissue oxygenation monitoring in assessing the need for transfusion should be evaluated

Cerebral Oxygenation During the First Days of Life in Preterm and Term Neonates:Differences Between Different Brain Regions

Near-infrared spectroscopy is a noninvasive method for monitoring brain oxygenation. The aim of the study was to investigate differences between cerebral oxygenation in different brain regions in newborns. In a prospective study, we monitored simultaneously left and right frontoparietal and temporo-occipital regional cerebral oxygen saturation (rScO(2)) and cerebral fractional tissue extraction (cFTOE: (arterial oxygen saturation (SaO(2)) - rScO(2))/SaO(2)) using near-infrared spectroscopy. A 2-h measurement was performed on d 1, 3, and 7. We included 10 very preterm (GA = 37 wk) neonates. Limits of agreement for difference of the measurements between different places were determined using the Bland-Altman method. In all subgroups, the rScO(2) and cFTOE values at different regions were not different. Limits of agreement were between +/- 14 and +/- 18% for all subgroups. Left-to-right differences were small between different postnatal and GAs. A decrease and increase over time for rScO(2) and cFTOE values was detected for all four brain regions, most pronounced for infants with G

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

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) - 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