Near-infrared spectroscopy as a diagnostic tool for necrotizing enterocolitis in preterm infants

Background We aimed to investigate whether splanchnic tissue oxygen saturation (r(s)SO(2)) measured by near-infrared spectroscopy (NIRS) could contribute to the early diagnosis of necrotizing enterocolitis (NEC). Methods We retrospectively included infants with suspected NEC, gestational age <32 weeks and/or birth weight <1200 g in the first 3 weeks after birth. We calculated mean r(s)SO(2), cerebral tissue oxygen saturation (r(c)SO(2)), variability of r(s)SO(2)(coefficients of variation [r(s)CoVAR] = SD/mean), and splanchnic-cerebral oxygenation ratio ([SCOR] = r(s)SO(2)/r(c)SO(2)) in the period around the abdominal radiograph to confirm or reject NEC. Results Of the 75 infants, 21 (28%) had NEC (Bell's stage >= 2). Characteristics of infants with and without NEC differed only on mechanical ventilation and nil-per-os status. R(s)SO(2)tended to be higher and r(c)SO(2)lower in infants with NEC. R(s)CoVAR (median [range]) was lower (0.11 [0.03-0.34]) vs. 0.20 [0.01-0.52],P = 0.002) and SCOR higher (0.64 [0.37-1.36]) vs. 0.47 [0.16-1.09],P = 0.004) in NEC infants. Adjusted for postnatal age, mechanical ventilation, and nil-per-os status, a 0.1 higher r(s)CoVAR decreased the likelihood of NEC diagnosis with likelihood ratio (LR) 0.38 (95% CI 0.18-0.78) and a 0.1 higher SCOR increased it with LR 1.28 (1.02-1.61). Conclusions Using NIRS, high SCOR may confirm NEC and high variability of r(s)SO(2)may rule out NEC, when suspicion arises. Impact Near-infrared spectroscopy may contribute to the diagnosis of necrotizing enterocolitis. When clinical signs are present a high splanchnic-cerebral oxygenation may indicate necrotizing enterocolitis. A low splanchnic-cerebral oxygenation ratio and high variability of splanchnic tissue oxygen saturation may rule out necrotizing enterocolitis. Whether a bedside real-time availability of the splanchnic-cerebral oxygenation ratio and variability of splanchnic tissue oxygen saturation improves NEC diagnosis needs to be further investigated.

Automated summary

The study suggests that using NIRS to measure the ratio of splanchnic tissue oxygen saturation to cerebral tissue oxygen saturation may aid in the early diagnosis of NEC in infants. High variability of splanchnic tissue oxygen saturation and low splanchnic-cerebral oxygenation ratio may rule out NEC, while a high splanchnic-cerebral oxygenation ratio may confirm NEC.