Influence of pulmonary factors on pulse oximeter saturation in preterm infants

Abstract

In infants with BPD, there was large variation in the slope of the curve relating SpO2% to inspired oxygen fraction in the SpO2 range 85%-95%. Slopes were considerably steeper at lower than higher SpO2, especially in infants with least severe BPD, meaning that higher SpO2 target values are intrinsically much more stable. Steep slopes below 90% SpO2 may explain why some infants appear dependent on remarkably low oxygen flows.

Effect of a smaller target range on the compliance in targeting and distribution of oxygen saturation in preterm infants

“…This could lead to more intrinsic stability in infants,11 but we also recognised that complying with this smaller range could be challenging for the NICU nurses 5 11 12. We studied the effect of narrowing TR towards the higher end on the distribution of SpO 2 and compliance in SpO 2 targeting during oxygen therapy.…”

Outcomes of Two Trials of Oxygen-Saturation Targets in Preterm Infants

“…8 The higher range includes the plateau of the oxyhemoglobin dissociation curve, where oxygen saturation fluctuates less with changing partial pressure of arterial oxygen and the slope of oxygen saturation versus the fraction of inspired oxygen (FIO 2 ) is flatter, 23 which makes targeting easier. This may help explain why, during oxygen treatment, none of the NeOProM trials achieved a median value of actual oxygen saturation below 89% among infants in the lowertarget groups.…”

Development and preclinical testing of an adaptive algorithm for automated control of inspired oxygen in the preterm infant

“…The K p modification was by multiplication of the standing value of K p by a factor in the range 0.5–1.5 for rFiO 2 21%–60%. Adaptation of K p in this way acknowledges the inverse proportional relationship between gain and severity of lung disease that has been observed in this population 24 25…”

“…A further challenge for automated control of oxygen delivery is that the magnitude of the SpO 2 response to FiO 2 adjustments (system gain) varies over time, related in large part to the evolution of lung dysfunction 24 25. This calls for a control algorithm that can adapt to the current severity of lung dysfunction, a feature incorporated into only one of the contemporary automated control algorithms 8…”