Splanchnic-cerebral oxygenation ratio associated with packed red blood cell transfusion in preterm infants

Abstract

Background: Splanchnic-cerebral oxygenation ratio (SCOR), the ratio of splanchnic tissue oxygen (StO2s) to simultaneously measured cerebral tissue oxygen (StO2c), has been described as a surrogate to detect impaired splanchnic oxygenation associated with hypoperfusion status such as necrotizing enterocolitis. This concept is based on the presumption that any change in SCOR indicates a corresponding change in splanchnic tissue oxygenation as the numerator, whereas cerebral tissue oxygenation as the denominator remains stable. However, it is questionable to utilise this concept to detect splanchnic oxygenation changes in the context of packed red blood cell transfusion (PRBCT). Aim: The current study examines the contribution of both cerebral and splanchnic oxygenation components to PRBCT-associated SCOR changes in preterm infants. Design: Prospective cohort study. Setting: Neonatal intensive care. Patients: Hemodynamically stable infants: Gestation <32 weeks; birth weight <1500 g; postmenstrual age <37 weeks: tolerating ≥120 ml/kg/day feed volume. Interventions: PRBCT at 15 ml/kg, over 4 h. Main Outcome Measures: Transfusion-associated changes were determined by performing mixed models for repeated measures analysis between the 4-h mean pre-transfusion values (SCOR 0, StO2s 0, and StO2c 0) and the post-transfusion hourly mean values for the next 28 h (SCOR 1–28, StO2s 1–28, and StO2c 1–28). Dunnett's method was used to adjust for the multiplicity of the p value. Results: Of 30 enrolled infants 14 [46.7%] male; median [IQR] birth weight, 923 [655–1064] g; gestation, 26.4 [25.5–28.1] weeks; enrolment weight, 1549 [1113–1882] g; and postmenstrual age, 33.6 [32.4–35.0] weeks, one infant was excluded because of corrupted NIRS data. With the commencement of PRBCT, SCOR demonstrated a downward trend throughout the study period. This drift was associated with an increasing StO2c trend, while StO2s remained unchanged throughout the study period. Conclusions and Relevance: PRBCT-associated SCOR decrease suggests improvement in cerebral oxygenation rather than worsening splanchnic oxygenation. Our study underlines that it is necessary to determine individual components of SCOR, namely cerebral and splanchnic StO2 to understand SCOR changes in the context of PRBCT.