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Adequate oxygen delivery to a tissue depends on sufficient oxygen content in arterial blood and blood flow to the tissue. Oximetry is a technique for the assessment of blood oxygenation by measurements of light transmission through the blood, which is based on the different absorption spectra of oxygenated and deoxygenated hemoglobin. Oxygen saturation in arterial blood provides information on the adequacy of respiration and is routinely measured in clinical settings, utilizing pulse oximetry. Oxygen saturation, in venous blood (SvO2) and in the entire blood in a tissue (StO2), is related to the blood supply to the tissue, and several oximetric techniques have been developed for their assessment. SvO2 can be measured non-invasively in the fingers, making use of modified pulse oximetry, and in the retina, using the modified Beer-Lambert Law. StO2 is measured in peripheral muscle and cerebral tissue by means of various modes of near infrared spectroscopy (NIRS), utilizing the relative transparency of infrared light in muscle and cerebral tissue. The primary problem of oximetry is the discrimination between absorption by hemoglobin and scattering by tissue elements in the attenuation measurement, and the various techniques developed for isolating the absorption effect are presented in the current review, with their limitations.

Aims: To study paracetamol (PCM) use as first line therapy for significant patent ductus arteriosus (sPDA) closure, stratified by echocardiography. Method(s): In this retrospective observational study, a prepublished score comprising PDA size and velocity, PDA:left pulmonary artery ratio, diastolic flow in main and LPA, LA:Ao ratio and left ventricular:aortic ratio were included for shunt severity. Successful closure was defined a priori as closure or >=50% reduction in score. Comparisons were made between infants with sPDA who were treated and not treated. Result(s): During November 2017-2018, 227 infants from 23 to 31+6 weeks' gestational age (GA) were admitted; 50 (22%) infants were diagnosed with PDA, 32 treated with PCM, overall treatment rate of 32/227 (14%). Successful therapy was noted in 23/32 (72%) and was higher when treated at <=7 days (80 versus 68%, p =.68), in infants >26 weeks GA (62.5 versus 100%, p =.07) and BW >1000 g (65.4 versus 100%, p =.14). Univariate analysis noted statistical significance only for GA. Eighteen infants were managed conservatively. Treated infants had a lower GA and BW, higher composite ECHO score (14.4 +/- 0.5 versus 19 +/- 0.4, p <.001). Conclusion(s): Composite scoring helped reduce exposure, and focus more on infants with lower GA and BW with greater shunt severity.Copyright © 2019 Informa UK Limited, trading as Taylor & Francis Group.

Objective The study aimed to assess the association of nucleated red blood cells (NRBC), a surrogate of intrauterine hypoxia, and elevated pulmonic vascular resistance (E-PVR) and oxygen requirement after minimally invasive surfactant therapy (MIST). Study Design Retrospective study of a cohort of preterm neonates that received MIST in a single unit. Results NRBC were measured in 65 of 75 (87%) neonates administered MIST during the period. In total, 22 of 65 (34%) infants had pre-MIST echocardiography (ECHO). Neonates with elevated NRBC (predefined as >5 x 10 9 /L, n = 16) required higher post-MIST fraction of inspired oxygen (FiO 2) than neonates with normal NRBC (<1 x 10 9 /L, n = 17; FiO 2 = 0.31 +/- 0.10 and 0.24 +/- 0.04, respectively, p = 0.02). NRBC correlated positively with % of time in right to left ductal shunt (r = 0.51, p = 0.052) and inversely with right ventricular stroke volume (r = -0.55, p = 0.031) and time to peak velocity to right ventricular ejection time ratio (r = -0.62, p < 0.001). Conclusion Elevated NRBC are associated with elevated FiO 2 after MIST and elevated E-PVR. Intrauterine hypoxia may impact postnatal circulatory adaptations and oxygen requirement. Key Points Post-MIST FiO2 requirements are significantly higher in infants with elevated NRBC. NRBC correlates positively with elevated PVR in neonates requiring. Intrauterine hypoxia may play a role in postnatal circulatory adaptations in neonates with RDS.Copyright © 2021. Thieme. All rights reserved.

Aims: To study paracetamol (PCM) use as first line therapy for significant patent ductus arteriosus (sPDA) closure, stratified by echocardiography. Method(s): In this observational study, a pre-published score comprising PDA size & velocity, PDA: left pulmonary artery ratio, diastolic flow in main and LPA, LA: Ao ratio and left ventricular: aortic ratio were included for shunt severity. Successful closure was defined a priori as closure or >= 50% reduction in score. Comparisons were made between infants with sPDA who were treated and not treated. Result(s): During November 2017-18, 227 infants from 23-31+6 weeks' gestational age (GA) were admitted; 50 (22%) infants were diagnosed with PDA, 32 treated with PCM, overall treatment rate of 32/227 (14%). Successful therapy was noted in 23/32 (72%) and was higher when treated at <=7 days (80% vs 68%, P = 0.68), in infants >26 weeks GA (62.5 vs 100%, P = 0.07) and BW >1000 g (65.4 vs 100%, P = 0.14). Univariate analysis noted statistical significance only for GA. 18 infants were managed conservatively. Treated infants had a lower GA and BW, higher composite ECHO score (14.4 +/- 0.5 vs 19 +/- 0.4, P < 0.001). Conclusion(s): Composite scoring helped reduce exposure, and focus more on infants with lower GA and BWwith greater shunt severity.

Objectives: To ascertain the impact of skin-to-skin care between parents and infants on cardiac function and cerebral blood flow in preterm infants. Study design: We undertook a prospective study of 40 self-ventilating preterm infants at a quaternary center and assessed cardiac performance and cerebral blood flow. Assessments were carried out two hours before skin-to-skin care and then 60 minutes after skin-to-skin care (with the infant still on parent and turned supine). Result(s): Infants were 30.5 +/- 0.6 weeks' gestational age and 1378 +/- 133 g birthweight. Axillary temperature noted a nonsignificant increase during skin-to-skin care from 36.7 +/- 0.07degreeC to 36.9 +/- 0.07degreeC (P =.07). Cardiac contractility (right ventricular fractional area change [26.5% +/- 0.3% vs 27.8% +/- 0.4; P <.001] and tricuspid annular plane systolic excursion [0.73 +/- 0.03 cm vs 0.77 +/- 0.03 cm; P =.02]) increased significantly, coincident with decreased measures of pulmonary vascular resistance. An increase in systemic cardiac output was associated with increased cerebral blood flow and reduced middle cerebral artery resistive index (0.81 +/- 0.02 vs 0.74 +/- 0.02; P =.0001). Conclusion(s): We documented a significant circulatory beneficial adaptation to a common neonatal practice. These findings align with previously documented physiologic benefits in cardiorespiratory stability and cardiac rhythm in preterm infants, and may be mediated through modulation of the autonomic nervous system.Copyright © 2020 Elsevier Inc.