Effects of red blood cell transfusion on cerebral hemodynamics of preterm neonates.

Significance: Anemia is a common problem in preterm neonates, and red blood cell transfusion (RBCT) is used to improve oxygen delivery. However, RBCT is associated with complications, although an increase in cerebral oxygenation has been documented, and no universally accepted biomarker for the need for transfusion (i.e.

Cerebral baseline optical and hemodynamic properties in pediatric population: a large cohort time-domain near-infrared spectroscopy study.

Significance: Reference cerebral near-infrared spectroscopy (NIRS) data on the pediatric population are scarce, and in most cases, only cerebral oxygen saturation ( ) measured by continuous wave spatially resolved spectroscopy NIRS is reported. Absolute data for baseline optical and hemodynamic parameters are missing.

Aim: We aimed at collecting baseline cerebral optical parameters [absorption coefficient, ; reduced scattering coefficient, ; differential pathlength factor (DPF)] and hemodynamic parameters [oxy-hemoglobin content ( ), deoxyhemoglobin content (HHb), total hemoglobin content (tHB), ] in a large cohort of pediatric patients.

Application limits of the scaling relations for Monte Carlo simulations in diffuse optics. Part 2: results.

The limits of applicability of scaling relations to generate new simulations of photon migration in scattering media by re-scaling an existing Monte Carlo simulation are investigated both for the continuous wave and the time domain case. We analyzed the convergence properties in various scenarios by numerical methods, trying to derive practical guidelines for the judicious use of this approach, as well as a deeper understanding of the physics behind such relations. In the case of scaling of the absorption coefficient, the convergence is always rigorous both for the forward and inverse problems, relying on the derivatives with respect to the absorption coefficient.

Reference values for cerebral and peripheral tissue oximetry in children: A clinical TD-NIRS study.

Aim: Current non-invasive near-infrared spectroscopy (NIRS) tissue oximetry suffers from suboptimal reproducibility over probe repositioning, hindering clinical threshold establishment. Time Domain-NIRS (TD-NIRS) offers higher precision but lacks sufficient paediatric data, preventing effective clinical application. We aimed to establish reference ranges for cerebral and mid-upper arm (MUA) tissue haemodynamics in paediatric subjects using TD-NIRS and explore correlations with auxological variables.