Packed red blood cells transfusion in neonates: effect on FiO 2 and PaO 2 /SaO 2 ratio, and implications for neonatal saturation targeting.

OBJECTIVE: To assess the effect of blood transfusions in neonates on partial pressure of oxygen in arterial blood (PaO2 ), arterial hemoglobin oxygen saturation (SaO2 ) and arterial hemoglobin oxygen saturation as measured by pulse oximetry (SpO2 ).

STUDY DESIGN: Retrospective study of neonates that received a first blood transfusion while having an indwelling arterial line. We compared PaO2 , SaO2, SpO2, SaO2 /PaO2 ratio and fraction of inspired oxygen (FiO2 ) 12 h before and after blood transfusion.

RESULTS: Post-transfusion neonates had higher PaO2 and SaO2 , had lower SaO2 /PaO2 ratio, and received higher FiO2 with no change in SpO2 .

CONCLUSIONS: Post-transfusion, neonates had lower hemoglobin oxygen affinity. They received higher FiO2 and had higher PaO2 at the same SpO2 . We speculate that FiO2 was increased in order to maintain SpO2 . Larger prospective trials are needed to confirm our findings.