Regional splanchnic oxygen saturation for preterm infants in the first week after birth: reference values

Abstract

BACKGROUND: Near-infrared spectroscopy is used in the assessment of regional splanchnic oxygen saturation (r s SO 2 ), but solid reference values are scarce. We aimed to establish reference values of r s SO 2 for preterm infants during the first week after birth, both crude and modeled based on predictors. METHODS: We included infants with gestational age (GA) <32 weeks and/or birth weight <1200 g. We excluded infants who developed necrotizing enterocolitis or sepsis or who died. In the first week after birth, we determined a daily 2-h mean of r s SO 2 to assess its associations with sex, GA, postnatal age (PNA), small-for-gestational age (SGA) status, patent ductus arteriosus, hemoglobin, nutrition, and head circumference at birth and translated those into a prediction model. RESULTS: We included 220 infants. On day 1, the mean ± SD r s SO 2 value was 48.2% ± 16.6. The nadir of r s SO 2 was on day 4 (38.7% ± 16.6 smoothed line) to 5 (37.4%±17.3, actual data), after which r s SO 2 increased to 44.2% ± 16.6 on day 7. The final model of the reference values of r s SO 2 included the following coefficients: r s SO 2 = 3.2 − 7.0 × PNA + 0.8 × PNA 2 − 4.0 × SGA + 1.8 × GA. CONCLUSIONS: We established reference values of r s SO 2 for preterm infants during the first week after birth. GA, PNA, and SGA affect these values and need to be taken into account.

Study of the relationship between regional cerebral saturation and pCO2 changes during mechanical ventilation to evaluate modifications in cerebral perfusion in a newborn piglet model

“…In other words, between 15% and 33% of the transported O 2 is consumed (8). In our study, an inverse relationship between PaCO 2 and cerebral FTOE was observed, with a 37% reduction in O 2 consumption during hypercapnia and a 16% increase during hypocapnia, confirming previous findings in sheep, piglets, and human newborns (35).…”

“…In this context, we can assume that oxygen extraction increases when there is a decrease in the rSaO 2 , as the brain tissue compensates the decrease in CBF. As previously demonstrated, this is because rSaO 2 decreases due to vasoconstriction after hypocapnia, establishing an inverse relationship between FTOE and PaCO 2 (35).…”

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

“…This is especially in the background of the lack of normative values that allow us to define cerebral and splanchnic hypoxia. 11,45,46 As this is an observational study involving PRBCT, it is not possible to distinguish between an increase in oxygenation secondary to PRBCT and the effect of the increase in volume. A randomised controlled study of PRBCT versus saline in such a setting is ethically not permissible.…”

“…11,[47][48][49] Cerebral and splanchnic oxygenation vary with gestation, postnatal age, small for gestational age, haemoglobin, gender, and hemodynamically significant PDA. 6,22,23,46,50 Results of association of splanchnic oxygenation with feeding are also conflicting. 4,12,19,[41][42][43]51 These findings imply that it is prudent to account for these confounding factors in regional tissue oxygenation studies.…”

Could Near Infrared Spectroscopy (NIRS) be the new weapon in our fight against Necrotising Enterocolitis?

“…Therefore, research should focus on the use of routine NIRS in extreme preterm infants and micropremies, so we can start constructing normative ranges. A recent study by van der Heid et al ( 16 ) has brought us one step further as they conducted a relatively large NIRS study on preterm infants ( n = 220, <32 w and/or <1,500 g BW) and showed that gestational age, postnatal age, and small-for-gestational age status affect regional splanchnic oxygen saturation and need to be taken into account when interpreting regional splanchnic oxygen saturations using NIRS. In their study they provided a model so that reference values for infant regional splanchnic oxygen saturation can be computed with their formula based on those factors.…”