Fractional Tissue Oxygen Extraction Values Research Articles

Early or delayed cord clamping during transition of term newborns: does it make any difference in cerebral tissue oxygenation?

BackgroundAccording to the World Health Organization’s recommendation, delayed cord clamping in term newborns can have various benefits. Cochrane metaanalyses reported no differences for mortality and early neonatal morbidity although a limited number of studies investigated long-term neurodevelopmental outcomes. The aim of our study is to compare the postnatal cerebral tissue oxygenation values in babies with early versus delayed cord clamping born after elective cesarean section.MethodsIn this study, a total of 80 term newborns delivered by elective cesarean section were included. Infants were randomly grouped as early (clamped within 15 s, n:40) and delayed cord clamping (at the 60th second, n:40) groups. Peripheral arterial oxygen saturation (SpO2) and heart rate were measured by pulse oximetry while regional oxygen saturation of the brain (rSO2) was measured with near-infrared spectrometer. Fractional tissue oxygen extraction (FTOE) was calculated for every minute between the 3rd and 15th minute after birth. (FTOE = pulse oximetry value-rSO2/pulse oximetry value). The measurements were compared for both groups.ResultsThe demographical characteristics, SpO2 levels (except postnatal 6th, 8th, and 14th minutes favoring DCC p < 0.05), heart rates and umbilical cord blood gas values were not significantly different between the groups (p > 0.05). rSO2 values were significantly higher while FTOE values were significantly lower for every minute between the 3rd and 15th minutes after birth in the delayed cord clamping group (p < 0.05).ConclusionOur study revealed a significant increase in cerebral rsO2 values and a decrease in FTOE values in the delayed cord clamping (DCC) group, indicating a positive impact on cerebral oxygenation and hemodynamics. Furthermore, the DCC group exhibited a higher proportion of infants with cerebral rSO2 levels above the 90th percentile. This higher proportion, along with a lower of those with such parameter below the 10th percentile, suggest that DCC may lead to the targeted/optimal cerebral oxygenetaion of these babies. As a result, we recommend measuring cerebral oxygenation, in addition to peripheral SpO2, for infants experiencing perinatal hypoxia and receiving supplemental oxygen.

Evaluation of cerebral autoregulation of oxygen by NIRS method during postnatal transition period in term and late preterm newborns without resuscitation requirement.

Pulse oximetry is commonly used to monitor arterial oxygen saturation and heart rate during the transition period and reference intervals have been determined. However, the effect of the change in arterial oxygen saturation on tissue oxygenation does not seem to be the same. So, a non-invasive method for monitoring cerebral or regional tissue oxygenation will be potentially useful for vulnerable infants. This study aims to evaluate the effectiveness of cerebral autoregulation in the first 10 min after delivery in term and late preterm newborns without resuscitation requirement. Cerebral tissue oxygen saturation was measured in the first 10 min after birth with near-infrared spectroscopy (NIRS) from the left forehead. Peripheral oxygen saturation was measured with pulse oximetry from the right hand and cerebral fractional tissue oxygen extraction was calculated. Nineteen late preterms and 20 term infants were included in the study. There was no statistically significant difference between median cerebral tissue oxygen saturation and cerebral fractional tissue oxygen extraction values of late preterm and term infants (p < 0.001). There was a strong inverse relationship between cerebral tissue oxygen saturation and cerebral fractional tissue oxygen extraction (p < 0.001). In late preterm infants similar to term infants, arterial oxygen saturation and cerebral tissue oxygen saturation increased with time, but inverse reduction of cerebral fractional tissue oxygen extraction showed the presence of an active autoregulation in the brain. This can be interpreted as the ability of the brain to protect itself from hypoxia by regulating oxygen uptake during normal fetal-neonatal transition process. A larger scale multi-center randomized control trial is now needed to further inform practice.

Role of Near-Infrared Spectroscopy in Monitoring the Clinical Course of Asphyxiated Neonates Treated with Hypothermia.

Hypoxic-ischemic encephalopathy (HIE) affects millions of newborns annually, especially in low-resource settings. Real-time monitoring of hypoxic-ischemic brain damage is urgently needed for assessment of severity and management of neonates with birth asphyxia. Aim of the work is monitoring of near-infrared spectroscopy (NIRS)-measured cerebral regional oxygen saturation (cRSO2) and cerebral fractional tissue oxygen extraction (FTOE) in neonates after birth asphyxia in relation to their clinical course. Forty asphyxiated-term and near-term neonates with mild to severe HIE admitted at neonatal intensive care unit of Alexandria University Maternity Hospital from March to October 2019, received therapeutic hypothermia (TH) and had continuous NIRS monitoring of cRSO2 for 72 hours. Infants were categorized into HIE with seizing and nonseizing groups, and abnormal and normal magnetic resonance imaging (MRI) groups. Clinical seizures (CS) occurred in 15 (37.5%) of HIE neonates and 13.3% of them died (n = 2). In the current study, significantly higher cRSO2 and lower FTOE values were found in the seizing infants as compared with nonseizing group (p < 0.001). NIRS-measured day 2-cRSO2 and day 1-FTOE were associated with CS in newborns with HIE and day 1-cRSO2 and FTOE were associated with abnormal MRI at 1 month of age. cRSO2 values were found to correlate positively with initial Thompson score especially in days 1 and 2. Further, neonates with CS were more likely to have MRI abnormalities at follow-up. NIRS measures may highlight differences between asphyxiated neonates who develop CS or later MRI abnormalities and those who do not. · Day 1 FTOE is the early and sensitive predictor for both clinical seizures and abnormal MRI.. · Cerebral oxygenation metrics help in selecting patients in urgent need of an early MRI scan.. · Cerebral oxygenation metrics can be used hand in hand with clinical assessment using Thompson score at admission to select patient candidate for therapeutic hypothermia..

Near-Infrared Spectroscopy to Predict the Course of Necrotizing Enterocolitis.

ObjectivesTo investigate whether cerebral, liver, and infraumbilical regional tissue oxygen saturation (rSO2) and fractional tissue oxygen extraction (FTOE) could be used to diagnose necrotizing enterocolitis (NEC) and complicated NEC (Bell’s stage 3B or death) during its early stages.MethodsA prospective observational cohort study of preterm infants with suspected or diagnosed NEC. We compared the mean eight-hour cerebral, liver, and infraumbilical rSO2 and FTOE values of infants with no NEC and definite NEC and of infants with uncomplicated and complicated NEC in the first forty-eight hours after onset of symptoms, suspicious for NEC. Furthermore, we determined cut-off values by generating receiver operating characteristics curves in case of significant differences in the first eight-hour mean values of rSO2 between infants with no NEC and definite NEC and between infants with uncomplicated and complicated NEC.ResultsWe included 33 patients: 13 no NEC, 10 with uncomplicated NEC, and 10 with complicated NEC. We found no significant differences in the first twenty-four hours after onset of symptoms in rSO2 and FTOE between infants with no NEC and definite NEC. In preterm infants with complicated NEC, we observed significantly lower cerebral, liver, and infraumbilical rSO2 and higher FTOE within twenty-four hours after onset of symptoms compared with infants with uncomplicated NEC. A continuous cerebral rSO2 ≤ 71% and liver rSO2 ≤ 59% in the first eight hours after onset of symptoms predicted the onset of complicated NEC with a sensitivity of 1.0 and specificity of 0.8, and a sensitivity of 1.0 and specificity of 1.0, respectively.ConclusionsBy measuring the cerebral and splanchnic oxygenation it is possible to differentiate complicated NEC from uncomplicated NEC. In our sample, NIRS monitoring did not proof useful for distinguishing between definite NEC and no NEC in preterm infants with clinical signs suspicious of NEC.

The relation between splanchnic ischaemia and intestinal damage in necrotising enterocolitis

ObjectivesThe underlying pathophysiology of necrotising enterocolitis (NEC) remains incompletely understood, particularly the role of intestinal perfusion. We aimed to determine the relation between cerebral and splanchnic fractional tissue oxygen extraction...

The Association between Multisite Near-Infrared Spectroscopy and Routine Hemodynamic Measurements in Relation to Short-Term Outcome in Preterms with Clinical Sepsis

Background: The added clinical value of multisite near-infrared spectroscopy (NIRS) monitoring to detect low organ tissue perfusion in preterm infants at risk of circulatory failure remains unclear. Objectives: To evaluate the associations between multisite NIRS measurements and clinical signs of circulatory failure in relation to short-term outcome in preterm infants with clinical sepsis. Methods: Prospective cohort study of preterm infants (gestational age <32 weeks) with clinical sepsis. We monitored cerebral, renal, and intestinal oxygen saturation using NIRS for 72 h following sepsis workup and calculated fractional tissue oxygen extraction (FTOE). We recorded clinical signs of circulatory failure every 8 h. We analyzed the associations between FTOE values, clinical signs of circulatory failure, and short-term outcome. Results: In 28 preterm infants with clinical sepsis, intraindividual and interindividual associations between NIRS values and clinical signs of circulatory failure were weak. At several points of time during the study period, cerebral and renal FTOE were higher in infants who developed intestinal complications compared with infants who did not, while clinical signs of circulatory failure never differed between groups. After correcting for multiple testing, significant differences disappeared. Conclusions: The associations between multisite FTOE values and clinical signs of circulatory failure were weak in preterm infants with clinical sepsis. Nevertheless, in contrast to clinical signs of circulatory failure, cerebral and renal FTOE values were associated with adverse short-term intestinal outcome in the uncorrected analyses. Multisite NIRS monitoring might help to detect critically low tissue oxygen delivery leading to adverse intestinal outcome not detected by routine hemodynamic measurements.

In preterm infants, ascending intrauterine infection is associated with lower cerebral tissue oxygen saturation and higher oxygen extraction.

Placental lesions are associated with neurological morbidity but the mechanism leading to morbidity is unclear. To provide insight into such a possible mechanism, we determined whether placental lesions were associated with regional cerebral tissue oxygen saturation (rcSO2) and fractional tissue oxygen extraction (FTOE) in preterm infants during their first 5 d after birth. We hypothesized that as a result of cerebral hypoperfusion, rcSO2 would be lower and FTOE would be higher. In a prospective, observational study of 42 preterm infants (gestational age <32 wk), the infants' placentas were examined for histopathology. We measured rcSO2 and transcutaneous arterial oxygen saturation (SpO2) on days 1-5. FTOE was calculated as FTOE = (transcutaneous SpO2 - rcSO2)/transcutaneous SpO2. Only three placentas showed no pathology. Ascending intrauterine infection (AIUI) (n = 16) was associated with lower rcSO2 and higher FTOE values on days 2, 3, and 4 (P ≤ 0.05). Other placental lesions were not associated with rcSO2 and FTOE. AIUI is associated with lower rcSO2, and higher FTOE shortly after birth. The effect it has on cerebral oxygenation might be the mechanism leading to neurodevelopmental problems.

PO-0725e Cerebral Tissue Oxygenation At Birth In Term Infants: Comparison Between Early And Late Cord Clamping

Background and aims The aim of our study is to compare the postnatal cerebral tissue oxygenation values in babies with early versus late cord clamping born after elective C/S. Methods In this prospective, observational study, we included term newborns delivered by elective C/S. Babies were segregated into two groups as early (within 15 seconds) and late cord clamping (at 60th seconds). Peripheral arterial oxygen saturation (SpO 2 ) and heart rate were measured using pulse oximetry (Nellcor N200) and regional oxygen saturation of the brain (rSO 2 brain) were measured (Invos 5100) between the 3rd and15th minutes and recorded every minute. Fractional tissue oxygen extraction (FTOE) was calculated for each minute (FTOE=pulse oximetry value-rSO 2 /pulse oximetry value). The measurements were compared for both groups. Results The demographical characteristics, SpO 2 levels, heart rates and umbilical cord blood gas values were not significantly different between the groups (p > 0.05). Cerebral oxygenation measurements and FTOE values were significantly higher for each minute in the late cord clamping group (p 2 was faster and the rSO 2 plateau was reached earlier in the late cord clamping group (Figure). Conclusions In our study we found that rSO 2 brain measurements and FTOE values were higher in the late cord clamping group without the need for any therapy as a result of high bilirubin and hematocrit levels.

PS-185 Intestinal Oxygen Extraction Strongly Correlates With I-fabp Levels, A Marker For Intestinal Damage

Background and aim It remains unknown whether near-infrared spectroscopy (NIRS) can be used to assess intestinal perfusion. Intestinal fatty acid binding proteins in plasma (I-FABPp) and urine (I-FABPu) are a direct measure of intestinal epithelial cell damage that may occur after intestinal hypoperfusion. We measured splanchnic fractional tissue oxygen extraction (FTOE) and correlated these FTOE values with I-FABP levels in preterm infants in the first 16 h after onset of necrotizing enterocolitis (NEC). Methods Preterm infants born between October 2010 and November 2012 were prospectively included when NEC was diagnosed (Bell stage ≥2). Regional tissue oxygen saturation of the liver (r liv SO2) and infra-umbilical (r int SO2) region were measured continuously by NIRS. Mean 8-hour FTOE values were calculated: FTOE = (SpO 2 -rSO 2 )/SpO 2 . Plasma and urine samples collected in the first 16 h after onset of symptoms were used for analysis. Spearman’s correlation test was used to calculate correlation coefficients. Results Twenty-one preterm infants were included (median [range] gestational age 28 [25–36] weeks, birth weight 1290 [740–2400] grams). Median [range] liver FTOE (livFTOE) was 0.33 [0.07–0.81], infra-umbilical FTOE (intFTOE) 0.48 [0.13–0.82], I-FABPp 16.3 [0.54–3748] ng/mL, and I-FABPu 89.9 [3.2–23,336] ng/mL. Table 1 shows strong positive correlations between FTOE and I-FABP levels. Conclusion High intFTOE values, suggestive of an impaired intestinal blood flow, correlated strongly with I-FABP, i.e. with the extent of intestinal epithelial cell damage. These results indicate that intestinal NIRS monitoring can be used to assess intestinal perfusion in preterm infants with an impaired intestinal blood flow such as occurs in NEC.

PO-0494 Longterm Multichannel Nirs Monitorization Is Feasable And Valuable In Multisystem Disease Of Term Newborns: Abstract PO-0494 Table 1

Background Near infrared spectroscopy (NIRS) is evolving into a clinical monitorization method providing information regarding not only cerebral but abdominal or renal tissue oxygenation (rSO2) as well. Fractional tissue oxygen extraction (FTOE) is calculated from NIRS measurements and arterial haemoglobin oxygen saturation (SpO2) measured by pulse oxymeter. Multichannel NIRS devices maybe very helpful in newborns with multisystem problems enabling realtime simultaneous measurements of rSO2 from different parts of the body. Pulse oxymeter integrated into a multichannel NIRS device provides simultaneous SpO2 monitoring making FTOE calculations more accurate and easier. Methods Three term newborns; 2 undergoing therapeutic hypothermia for hypoxic ischaemic encephalopathy grade II, 1 with critical pulmonary stenosis before and after cardiac surgery were monitored by multichannel NIRS (Sensmart X-100, NONIN, USA) device including cerebral, abdominal, renal rSO2 and SpO2 probes. FTOE was calculated using the equation; (SpO2-rSO2)/SpO2. Results Duration of monitorization and rSO2 and FTOE values of different body sites are presented in table with mean±SD. Discussion Longterm simultaneous monitoring of tissue oxygenation in brain, abdomen and kidneys is useful while following newborns with multisystem problems requiring hypothermia or circulatory medications to titrate the treatment accordingly. NIRS device with integrated pulse oxymeter maybe helpful for realtime calculation of FTOE to assess hemodynamics.

Cerebral tissue oxygenation index, cardiac output and superior vena cava flow in infants with birth weight less than 1250 grams in the first 48 hours of life

BackgroundNear-infrared spectroscopy is a non-invasive method of assessing cerebral oxygenation. Functional echocardiography is increasingly used by neonatologists in the assessment of cardiovascular function. AimsTo correlate cerebral tissue oxygenation index (cTOI) and cardiac output in infants less than 1250g at 6, 12, 24 and 48hours of age. Study designA prospective observational study. SubjectsNewborns with birth weight<1250g. Outcome measuresSerial assessments of superior vena cava (SVC) flow, right and left ventricular outputs, ductus arteriosus and cTOI were performed at 6, 12, 24 and 48hours of age. Clinical parameters, including mean blood pressure, mean airway pressure, blood gas parameters and oxygen saturations were recorded. Results22 neonates were enrolled following parental consent. The mean birth weight was 851g (SD±201), mean gestational age was 25.9weeks (SD±1.7). Mean SVC flow at 6hours of age was 56.8ml/kg/min and increased to 68.6ml/kg/min at 48hours of age. 9 infants (41%) had at least one measurement of low SVC flow (<41ml/kg/min) in the first 48hours. Mean cTOI was 65.2% at 6hours of age, 63.9% at 12hours of age, 68.8% at 24hours of age and 67.2% at 48hours of age. Cerebral fractional tissue oxygen extraction values were highest at 12hours (0.31±0.09). There was no correlation between SVC flow and cTOI values. ConclusionSVC flow, left and right ventricular output increased during first 48hours of life. cTOI decreased at 12hours of age with a concomitant increase in fractionated oxygen extraction. These changes reflect transitional changes in both cardiac and cerebral hemodynamics in extremely low gestational age newborns during the first 48hours.

787 What is the Effect PDA and Its Medical Closure on Cerebral and Abdominal Tissue Oxygenation in Preterm Newborns?

Background and AimPatent ductus arteriosus (PDA) is a frequent problem in preterms known to have significant effects on organ perfusion. The aim of this study was to investigate the difference...

109 Neonatal Cerebral Oxygenation is Associated with Neurodevelopmental Outcome of Preterm Infants at 2 to 3 Years of Age

Background and aimsDisturbed cerebral oxygenation during the neonatal period might pose preterm infants at risk for neurological deficits. Our aim was to determine whether regional cerebral tissue oxygen saturation (rcSO2)...

Cerebral Oxygen Saturation and Extraction in Preterm Infants With Transient Periventricular Echodensities

Our aim was to determine regional cerebral tissue oxygen saturation and fractional tissue oxygen extraction in preterm infants with transient periventricular echodensities. We hypothesized that as a result of reduced cerebral perfusion, regional cerebral tissue oxygen saturation will be lower and fractional tissue oxygen extraction will be higher during the first days after birth. This was a prospective, observational study of 49 preterm infants (gestational age median: 30.1 weeks [26.0-31.8 weeks]; birth weight median: 1220 g [615-2250 g]). We defined transient periventricular echodensities as echodensities that persisted for >7 days. Regional cerebral tissue oxygen saturation was measured on days 1-5, 8, and 15 after birth. Fractional tissue oxygen extraction was calculated as (transcutaneous arterial oxygen saturation--regional cerebral tissue oxygen saturation)/transcutaneous arterial oxygen saturation. Transient periventricular echodensities were found in 25 of 49 infants. During the first week we found no difference between the 2 groups for cerebral tissue oxygen saturation and fractional tissue oxygen extraction values. On day 15 after birth, cerebral tissue oxygen saturation was lower in preterm infants with transient periventricular echodensities (66%) compared with infants without echodensities (76%) (P = .003). Fractional tissue oxygen extraction in infants with transient periventricular echodensities (0.30) was higher than fractional tissue oxygen extraction in infants without transient periventricular echodensities (0.20) (P < .001). The differences could not be explained by confounding variables. Persistent transient periventricular echodensities may be associated with increased cerebral oxygen demand after the first week after birth, which is contrary to our hypothesis. Cerebral oxygenation may be involved in the recovery of perinatal white matter damage.