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

Area of Science:

• Neonatal physiology
• Medical instrumentation
• Clinical assessment

Background:

• Near-infrared spectroscopy (NIRS) is crucial for assessing regional splanchnic oxygen saturation (rS02).
• Establishing reliable reference values for rS02 in preterm infants is essential but currently limited.
• This study addresses the scarcity of reference data for rS02 in the neonatal intensive care unit.

Purpose of the Study:

• To establish reference values for regional splanchnic oxygen saturation (rS02) in preterm infants during their first week of life.
• To develop a predictive model for rS02 based on key infant characteristics.
• To provide a tool for more accurate interpretation of NIRS-derived rS02 in vulnerable neonates.

Main Methods:

• Included preterm infants (gestational age <32 weeks and/or birth weight <1200g), excluding those with necrotizing enterocolitis, sepsis, or mortality.
• Measured daily 2-hour mean rS02 values throughout the first postnatal week.
• Analyzed associations between rS02 and factors like gestational age (GA), postnatal age (PNA), and small-for-gestational age (SGA) status to build a prediction model.

Main Results:

• A total of 220 preterm infants were analyzed.
• Mean rS02 was 48.2% ± 16.6 on day 1, decreasing to a nadir around day 4-5 (37.4%-38.7%) before rising to 44.2% ± 16.6 by day 7.
• The predictive model incorporated PNA, SGA status, and GA, yielding coefficients: rS02 = 3.2 - 7.0*PNA + 0.8*PNA^2 - 4.0*SGA + 1.8*GA.

Conclusions:

• Reference values for rS02 in preterm infants were successfully established for the first postnatal week.
• Gestational age, postnatal age, and SGA status are significant determinants of rS02.
• The developed model allows for individualized interpretation of rS02, accounting for these critical factors.