Abstract:Objective To study the clinical value of intestinal regional oxygen saturation (rSO2) and C-reactive protein (CRP) in the diagnosis of necrotizing enterocolitis (NEC) in preterm infants. Methods A prospective observational study was conducted among the preterm infants who were hospitalized in Children's Hospital Affiliated to Anhui Medical University, from October 2020 to December 2021, with 22 infants in the NEC group and 35 infants in the non-NEC group. Intestinal rSO2 was monitored 24 hours after a confirmed diagnosis of NEC in the NEC group, and serum CRP levels were measured before anti-infection therapy. In the non-NEC group, intestinal rSO2 monitoring and serum CRP level measurement were performed at the corrospording time points. The two groups were compared in terms of intestinal rSO2 and serum CRP level. The receiver operating characteristic (ROC) curve was used to analyze the value of intestinal rSO2 alone, serum CRP alone, and intestinal rSO2 combined with CRP in the diagnosis of NEC in preterm infants. Results Compared with the non-NEC group, the NEC group had a significantly lower level of intestinal rSO2 (P<0.05) and a higher serum CRP level (P<0.05). The ROC curve analysis showed that intestinal rSO2 had an optimal cut-off value of 50.75% in the diagnosis of NEC in preterm infants, with a sensitivity of 81.8%, a specificity of 85.7%, and an area under the ROC curve (AUC) of 89.4%; CRP had an optimal cut-off value of 12.05 mg/L in the diagnosis of NEC in preterm infant, with a sensitivity of 72.7%, a specificity of 74.3%, and an AUC of 74.8%; intestinal rSO2 combined with CRP had a sensitivity of 90.9%, a specificity of 77.1%, and an AUC of 91.9% in the diagnosis of NEC. The AUC of intestinal rSO2 alone in the diagnosis NEC was higher than that of CRP (P<0.05). There was no significant difference in the AUC between intestinal rSO2 alone and intestinal rSO2 combined with CRP (P>0.05). Conclusions The value of intestinal rSO2 in the diagnosis NEC is higher than that of CRP, and is equivalent to that of the combination of intestinal rSO2 and CRP in preterm infants.