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One of the problems of near-infrared-spectroscopy (NIRS) measurements is low reproducibility. The aim of the present study was to introduce quality criteria to increase reproducibility of peripheral NIRS measurements. In a prospective cohort study in 40 neonates, repeated NIRS measurements were performed on the calf. During five "reapplication" periods (of NIRS optodes), five "measurements" (venous occlusions) were performed. Tissue oxygenation index (TOI), mixed venous oxygenation (SvO2), fractional oxygen extraction (FOE), hemoglobin flow (Hbflow), oxygen delivery (DO2), and oxygen consumption (VO2) were assessed. Measurements with linear changes during venous occlusions were included for further analysis (first quality criterion: R(2)>0.95). The second quality criterion was the equation 0 < or = TOI-SvO2 < or = (SaO2-SvO2)x0.2. Variance components and mean standard deviations were analyzed after introduction of the quality criteria. Variance components of reapplication and measurement decreased after introduction of the second quality criterion (TOI: 46.6-35.0%, SvO2: 76.8-38.2%, FOE: 73.1-37.5%, Hbflow: 70.3-51.9%, DO2: 71.5-52.7%, and VO2: 70.9-63.8%). Mean standard deviations of TOI (6.6+/-3.0 to 4.7+/-3.2%), SvO2 (11.1+/-4.8 to 5.7+/-3.9%), FOE (11.3+/-4.8 to 5.9+/-4.0%), Hbflow (4.3+/-2.0 to 2.9+/-1.6 micromol100 mLmin), and DO2 (17.8+/-7.6 to 11.4+/-6.2 micromol100 mLmin) decreased significantly, too. Only 12% of measurements fulfilled both quality criteria. With the introduction of two quality criteria, test-retest variability of peripheral NIRS measurements decreased significantly and reproducibility increased significantly.

The aim of this study was to analyse changes in peripheral oxygenation in healthy term neonates within the first week of life with near-infrared spectroscopy and venous occlusion. Oxygen delivery did not change with increasing age. Oxygen consumption and fractional oxygen extraction increased, whereas tissue oxygenation index decreased with increasing age. N ear-infrared spectroscopy (NIRS), in combination with venous occlusion, enables measurements of peripheral oxygenation and perfusion. [1][2][3] In the present study, we carried out repeated measurements of peripheral oxygenation in healthy term neonates within the first week of life. The aim was to analyse changes in oxygen delivery (DO 2 ), oxygen consumption (VO 2 ), fractional oxygen extraction (FOE), tissue oxygenation index (TOI), mixed venous oxygenation (SvO 2 ), haemoglobin flow (Hbflow) and vascular resistance, to obtain normal values. METHODSNIRS measurements (NIRO 300, Hamamatsu Photonics, Shizuoka, Japan) and venous occlusions were carried out in each of 50 neonates twice within the first week of life. The local ethics committee approved the study.NIRS measures changes in oxygenated haemoglobin, deoxygenated haemoglobin, total haemoglobin and TOI. Measurements were carried out on neonates in the supine position during sleep after feeding. The two NIRS optodes were placed over the left forearm with a distance of 3.5 cm. Each measurement consisted of at least three venous occlusions lasting 20 s, without movement (artefacts), obtained with a pneumatic cuff placed around the upper arm.Heart rate and oxygen saturation (haemoglobin; SaO 2 ) were measured by pulse oximetry on the wrist. Central and peripheral temperatures were measured continuously. Mean arterial pressure (MAP) was measured before and after venous occlusions.Hbflow/min was calculated from the increase in total haemoglobin during the 20-s venous occlusion. Further parameters were calculated as follows: DO 2 = Hbflow646SaO 2 ; VO 2 = Hbflow646(SaO 2 2SvO 2 )where SvO 2 = oxygenated haemoglobin/total haemoglobin; FOE = DO 2 /VO 2 and vascular resistance = MAP6haemoglobin concentration/Hbflow. A blood sample was taken from each of 39 neonates within 24 h of the first measurement. VO 2 and DO 2 are measured in ml/kg/min. 4 Hbflow, DO 2 , VO 2 , FOE, TOI and SvO 2 for each neonate were determined as mean values of the three venous occlusions in each measurement. A paired t test was used for the comparison of the two measurements in each neonate. Vascular resistance was correlated with age and haemoglobin concentration to NIRS parameters by linear regression analysis. Data are mean (standard deviation (SD)). RESULTSThe 50 neonates (24 boys and 26 girls) had a mean age of 39.5 (SD 1

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Background: Tilting only the head influences cerebral haemodynamics in term and preterm neonates. Objective: To evaluate near-infrared spectroscopy (NIRS) as a method to detect changes of cerebral oxygenated (HbO₂) and deoxygenated haemoglobin (Hb) and ‘cerebral tissue-oxygenation-index’ (cTOI) while tilting. Furthermore to investigate whether the comparison of cTOI and ‘cerebral mixed venous oxygen saturation’ (tiltSvO₂), calculated out of the increase of HbO₂ and Hb, improves reproducibility. Methods: During five ‘reapplication’ periods of NIRS optodes on the left forehead of 40 neonates, five tilting manoeuvres of the head were performed. Changes of NIRS parameters during tilting were analysed. The first quality criterion was defined by a linear increase of total haemoglobin (HbT; r² > 0.95). The second quality criterion was: cTOI > tiltSvO₂ (= cTOI – tiltSvO₂> 0). Analysis of variance components and comparison of mean of standard deviations were applied to data after introduction of each quality criterion. Results: While HbO₂, Hb and HbT showed a linear increase in all neonates during tilting, cTOI did not change. With the introduction of the second criterion, mean cTOI increased from 73.7 ± 6.9 to 75.1 ± 6.9%, mean tiltSvO₂ decreased from 72.6 ± 7.1 to 65.3 ± 6.9% and mean of standard deviations of both parameters decreased. The analysis of variance components showed no significant change. Conclusion: A tilting-down manoeuvre of the head of term and preterm neonates can cause an increase of HbO₂, Hb and HbT. tiltSvO₂ can be calculated out of these changes. By introducing two quality criteria, reproducibility of cerebral NIRS measurements (cTOI and tiltSvO₂) improved.

Primary pulmonary lymphangiectasis (PPL) is a rare congenital developmental abnormality of the lung with a generally poor prognosis. Only a limited number of patients with neonatal-onset PPL have been reported to survive. We present the case of a male preterm infant (gestational age 34 weeks 6 days) with histologically confirmed PPL, complicated by hydrops fetalis, bilateral hydrothorax (treated in utero with pleuro-amniotic shunts), and immediate respiratory distress at birth. He survived after extensive neonatal intensive care therapy and was discharged home at the age of 7 months. At last follow up he was 3 years 7 months old, still requiring assisted ventilation via tracheostomy, having recurrent episodes of wheezing and had mild global developmental delay. This case demonstrates that survival beyond the neonatal period is possible even with severe PPL but long-term morbidity may be relevant, and multidisciplinary management and close follow up are essential.