ABSTRACT
Objective:To evaluate the diagnostic value of intestinal regional oxygen saturation（rSO 2）and fecal calprotectin in the occurrence and severity of necrotizing enterocolitis（NEC）in premature infants. Methods:A prospective observational study was conducted among premature infants admitted to Quanzhou Children's Hospital from October 2019 to December 2022. Intestinal rSO 2 was monitored within two hours of diagnosis of NEC，and fecal calprotectin was measured. Results:A total of 60 patients were included, including 30 cases with NEC and 30 cases without NEC, 14 cases of medical NEC, 16 cases of surgical NEC, and eight infants died due to NEC. Infants with NEC had lower intestinal rSO 2 [49（30，60）% vs. 66（60，69）%] and higher calprotectin levels [479（297，886）μg/g vs. 203（113，275）μg/g] than those in infants without NEC ( P<0.01). The levels of intestinal rSO 2 were lower in surgical NEC than those in medical NEC，and were lower in the death group than that in the survival group ( P<0.01)，but no similar difference was found in the levels of calprotectin. ROC curve analysis showed that intestinal rSO 2 combined with calprotectin had a sensitivity of 73%，a specificity of 100%，and the largest area under curve of 0.91 in the diagnosis of NEC. Intestinal rSO 2 had an optimal cut-off value of 31% in predicting death in infants with NEC，with a sensitivity of 100%，a specificity of 95%，and an area under curve of 0.99. Conclusion:Intestinal rSO 2 and fecal calprotectin can effectively identify the presence of NEC，and their combined detection can improve the diagnostic efficiency. Intestinal rSO 2 is a good predictor of the severity of NEC，but not fecal calprotectin.