Noninvasive evaluation of splanchnic tissue oxygenation using near-infrared spectroscopy in preterm neonates

Abstract

Background. Diagnosis of necrotizing enterocolitis (NEC) in preterm neonates is challenging. We hypothesized that regional splanchnic oxygen saturation (rsSO₂) measured by near-infrared spectroscopy (NIRS) is a biomarker for mesenteric perfusion.

Objective. To evaluate feasibility and safety of continuous rsSO₂ monitoring in preterm infants in the first 14 days of life.

Methods. Preterm neonates ≤30 weeks' gestation had a NIRS sensor placed in the left paraumbilical region within 48 h of birth. rsSO₂ was recorded every 30 s. Clinical data including pulse oximetry (SaO₂) were recorded. Fractional tissue oxygen extraction (FTOE) was computed as follows: (SaO₂ − rsSO₂) × 100/SaO₂.

Results. Of 21 infants enrolled, 2 were excluded because of skin breakdown and missing data. Daily mean rsSO₂ values decreased over the first 9 days (p < 0.0001) followed by an increase from day 10 (D10) to D14 (p = 0.0061). rsSO₂ was lower and FTOE was higher in infants with feeding intolerance compared to those without feeding intolerance (p = 0.0043). rsSO₂ accounted for ≥99.5% of the variance in FTOE. Two neonates with NEC had persistently low rsSO₂ with loss of variability preceded or followed by very high rsSO₂.

Conclusions. We have reported feasibility, safety and ranges for rsSO₂ for a small number of preterm infants in the first 2 weeks of life.

Keywords:

• Necrotizing enterocolitis
• spontaneous ileal perforation
• feeding intolerance
• regional oxygen saturation
• pulse oximetry
• fractional tissue oxygen extraction

Acknowledgements

We gratefully acknowledge the assistance of Barbara Maynarich, Information Resources Technician, and Cathy Eames, M.S.L.S. in searching the medical literature and preparing the bibliography. This study was supported by Children's Research Center of Michigan and Somanetics Corporation (Troy, MI, USA). The results reported in this manuscript were presented in part at the Pediatric Academic Societies' Annual Meeting on May 2, 2009 at Baltimore, Maryland.