176 - Effect of blood transfusions on pulse oximetry targets and cardiorespiratory profile in preterm infants

Packed red blood cells (PRBC) transfusions are commonly administered to preterm infants with a goal to improve cardiorespiratory status. The effect of transfusions on the burden of hypoxia and hyperoxia and their longitudinal effect on apnea, bradycardia, or desaturation beyond 3 days post-transfusion are unknown.

Objective:

Primary aim: To describe change in time spent below, within and above pulse oximetry (SpO₂) targets from 24 h pre- (baseline) to 7 days post-transfusion.

Secondary aim: To describe changes in apnea, bradycardia, and desaturations from baseline to 7 days post-transfusion. 

Design/Methods:

In this retrospective cohort study conducted at the tertiary NICU of Mount Sinai Hospital, Toronto, infants born between January 1, 2016, to December 31, 2021, at gestational age (GA) < 30 weeks or birthweight (BW) < 1000 g who received PRBC transfusions at age > 7 days were included. Infants with congenital, genetic, or cardiac abnormalities (except Patent Ductus Arteriosus), who received transfusion in the context of medical illness (defined as hemodynamic or respiratory instability, culture positive sepsis and necrotizing enterocolitis) and those who received repeat transfusion within 7 days were excluded. Target SpO₂ was 91-95%. Transfusion thresholds were Hemoglobin 100 g/dL and 85 g/dL from Day 8-14 and 85 g/ dL and 75 g/ dL for > 14 days, for infants receiving respiratory support and those in room air, respectively. SpO₂ percentage time spent within, below, and above target was averaged every 24 h from 24 h pre- to 7 days post-transfusion. The number of apnea, bradycardia, and desaturations during this time were recorded. Change in measurements over time was assessed using Repeated measures Analysis of Variance and pairwise comparisons were assessed on Tukey HSD test.

Results:

Ninety-eight infants with median (range) GA 25.86 (22.43, 29.86) and BW 740 (460, 990) g were included (Table 1). The cohort demonstrated an increase in time spent within the SpO₂ target (F (7, 761) =3.07, p = 0.003) on Days 2 and 6, with no change in time below (F (7, 764) = 0.46, p = 0.861) or above (F (7,761) = 1.48, p = 0.171) targets (Figure 1). The number of apnea (F(7, 761) =3.07, p = 0.003), bradycardia (F (7, 776) =5.88, p < .001), and desaturations (F (7, 776) = 5.41, p < .001) decreased over time and persisted at Day 7 post-transfusion (Figure 2).

Conclusion(s):

Post-transfusion, preterm infants demonstrate an increase in time spent with SpO2 target limits and a decrease in apnea, bradycardia, and desaturation events that persist on Day 7 post-transfusion, reflecting improved respiratory stability.