Splanchnic-Cerebral Oxygenation Ratio Decreases during Enteral Feedings in Anemic Preterm Infants: Observations under Near-Infrared Spectroscopy

Abstract

Background: Anemia is common in premature infants. Due to risks with red blood cell transfusions, many anemic infants are not transfused. The implications of this pathophysiologic status, especially at times of increased metabolic demand (enteral feedings), is not well understood. Near-infrared spectroscopy (NIRS) allows for the noninvasive determination of regional oxygen saturations (rSO₂) in tissues such as the brain and mesentery, giving insight into their oxygen sufficiency. Objective: We tested the hypothesis that during enteral feedings very low birth weight (VLBW) infants with a hematocrit ≤28% will experience a decrease in splanchnic rSO₂ and splanchnic-cerebral oxygenation ratio (SCOR). Methods: This prospective, observational, 2-centered study included VLBW infants receiving full enteral feedings with a hematocrit ≤28%. Cerebral and splanchnic rSO₂ were monitored via NIRS for 24 h. Average values were calculated for periods immediately preceding, during, and after each feeding. SCOR was calculated from these values (rSO₂ splanchnic/rSO₂ cerebral), and data were analyzed using a linear mixed effect model. Results: Fifty neonates with a median gestational age of 28 weeks (range 23-32), a birth weight of 1,118 ± 284 g (mean ± SD), and a hematocrit of 26 ± 2% (mean ± SD) were studied. During feedings, SCOR decreased significantly from baseline (0.72 ± 0.17 to 0.69 ± 0.17, p = 0.043). With feedings, there was a trend of decreased splanchnic rSO₂ (47 ± 11 to 45 ± 10, p = 0.057) and no change in cerebral rSO₂ (66 ± 8 to 66 ± 7, p = 0.597). Conclusions: VLBW infants with a hematocrit ≤28% had a decrease in SCOR and a trend towards decreased splanchnic rSO₂ with enteral feedings.

Influence of enteral feeding and anemia on tissue oxygen extraction after red blood cell transfusion in preterm infants

“…Dave et al 34 showed that both splanchnic oxygenation and cerebral-splanchnic oxygenation ratios increased soon after a bolus feed in late-preterm infants. In contrast, Braski et al 24 found that splanchnic oxygenation decreased during bolus feedings in preterm infants, suggesting that this discrepancy was plausibly due to their study subjects being more anemic than Dave et alʼs study subjects. Dani et al 35 found that bolus feeds increase splanchnic oxygenation, while continuous feeds do not.…”

“…Little is known about the effects of enteral feeding and anemia on regional tissue oxygen extraction following RBC transfusions . Enteral feeding may affect the relationship between blood transfusion and mesenteric FTOE in preterm infants . For many clinicians, withholding feeds during transfusions remains a controversial practice.…”

“…For many clinicians, withholding feeds during transfusions remains a controversial practice. Mesenteric oxygenation is decreased during enteral feedings in very‐low‐birth‐weight infants, but the effect of feeding on mesenteric oxygen extraction following RBC transfusion has not been rigorously studied . Additionally, preterm infants with anemia extract more oxygen compared to non‐anemic preterm infants .…”

“…1 Enteral feeding may affect the relationship between blood transfusion and mesenteric FTOE in preterm infants. 24 For many clinicians, withholding feeds during transfusions remains a controversial practice. Mesenteric oxygenation is decreased during enteral feedings in verylow-birth-weight infants, but the effect of feeding on mesenteric oxygen extraction following RBC transfusion has not been rigorously studied.…”

“…Mesenteric oxygenation is decreased during enteral feedings in verylow-birth-weight infants, but the effect of feeding on mesenteric oxygen extraction following RBC transfusion has not been rigorously studied. 24 Additionally, preterm infants with anemia extract more oxygen compared to non-anemic preterm infants. 25 Research delineating Hct threshold for optimal improvement in oxygen extraction following RBC transfusion is needed.…”