Splanchnic-cerebral oxygenation ratio as a marker of preterm infant blood transfusion needs

Premature neonates often receive red blood cell (RBC) transfusions to improve tissue perfusion and oxygen delivery. Clinical and laboratory indicators used to guide transfusion therapy are inadequate to determine physiologic need with high predictability and transfusions frequently do not result in clinical improvement. The splanchnic-cerebral oxygenation ratio (SCOR) provides insight into overall tissue oxygen sufficiency and can be determined using near-infrared spectroscopy (NIRS). Our aim was to assess the usefulness of SCOR as a marker for transfusion need in preterm infants.

This study was a prospective observational pilot study utilizing NIRS to analyze the SCOR in symptomatic anemic premature neonates receiving RBC transfusions and nontransfused asymptomatic premature neonates with similarly low hemoglobin (Hb) levels. Subject clinical status was determined based on frequency of apnea, bradycardia, pulse-oximetry desaturation events, heart rate, respiratory support, and feeding tolerance. We then assessed for any difference between baseline (pretransfusion) SCOR of 1) symptomatic subjects who improved after transfusion, 2) symptomatic subjects who did not improve, and 3) asymptomatic subjects.

The study included 52 subjects (34 transfused, 18 asymptomatic): mean birth weight was 1164 g, mean gestational age was 28.6 weeks, and mean Hb level was 9.0 g/dL. Of 34 transfused subjects, 19 improved (56%). Mean baseline SCOR values were lower in neonates who improved with transfusion, 0.61 ± 0.22, when compared to those without improvement, 0.75 ± 0.17, and asymptomatic neonates, 0.77 ± 0.16 (p = 0.03). Infants with a low baseline SCOR (≤ 0.73) were more likely to improve after transfusion (likelihood ratio, 2.8; 95% confidence interval, 1.1-6.7).

SCOR may help identify premature infants who will benefit from RBC transfusion.