Predictive Value Of Monitoring Intestinal Tissue Oxygen Saturation By Near-infrared Spectroscopy In Neonatal Necrotizing Enterocolitis

Objective:Necrotizing enterocolitis(NEC)is one of the most common gastrointestinal critical diseases in neonatal intensive care unit(NICU).It is characterized by acute onset,rapid progression,multiple and severe complications,and the mortality rate is high.The purpose of this study was to use near-infrared spectroscopy technology to monitor the regional oxygen saturation(r SO2)and intestinal hemoglobin concentration index(THI)of newborns with suspected and confirmed NEC,and to explore the feasibility of its early diagnosis of NEC.Methods:A prospective observational method was used to select newborns hospitalized in the Department of Neonatology of the Children’s Hospital of Anhui Medical University from October 2020 to August 2022,including the observation group(suspected NEC group and confirmed NEC group)and the control group(ordinary newborn group).Dynamic monitoring of r SO2 and THI in the intestines is started when the newborn has feeding intolerance,gastric retention and other suspected NEC manifestations.For newborns with a clear diagnosis of NEC(Bell II or III),the r SO2 and THI in the intestines are monitored within 24 hours after fasting.At the same time,the r SO2 and THI in the intestines of ordinary newborns with corresponding gestational age and no digestive system disease in the ward are monitored dynamically for 3 days in each group,three times a day,and the values are recorded continuously.After the neonates suspected of NEC developed into NEC(Bell II or III),they were directly included in the confirmed NEC group,and then continuously monitored the values for 3days to compare the differences of r SO2 and THI in the intestines of neonates in each group,and analyze their change rules.For neonates in suspected NEC group and confirmed NEC group,the predicted cutoff value of intestinal oxygen saturation for NEC was monitored by near-infrared spectroscopy using the subject working curve analysis.Results:A total of 151 cases met the inclusion criteria,including 4 cases with incomplete data,3 cases with insufficient monitoring time due to intestinal perforation immediately after the diagnosis of NEC,1 case with suspected NEC progressing to the diagnosis of NEC without timely re-monitoring,and 143 cases were excluded from the observation group with complete NIRS data.11 cases of suspected NEC newborns who developed into NEC(Bell II or III)were included in the confirmed NEC group after 3days of monitoring Sr SO2 and s THI again,43 cases in the final confirmed NEC group,50 cases in the suspected NEC group and 50 cases in the control group were included in the study.There was no statistically significant difference in the fetal age,birth weight,sex,mechanical ventilation rate of newborns in the control group,suspected NEC group and confirmed NEC group.The prevalence of patent ductus arteriosus,septicemia and anemia in neonates with NEC is high.The intestinal oxygen saturation of the confirmed NEC group was lower than that of the suspected NEC group(Intergroup effect: F=208.215,P < 0.001,time effect:F=4.459,P < 0.001),Inter-group * time interaction effect: F=2.860,P<0.001)and that of the suspected NEC group was lower than that of the control group.At the same time,the intestinal oxygen saturation monitored by the newborns in the confirmed NEC group fluctuated,but there was no obvious increase or decrease trend with time(P>0.05).Compared with the non-progressive NEC group and the control group,the intestinal THI of the confirmed NEC group was lower,and there was no significant relationship between the intestinal THI and time between the groups(Intergroup * time interaction effect: F=0.763,P>0.05).The analysis of the working characteristic curve of the subjects showed that the best cutoff value for the diagnosis of suspected NEC and NEC(Bell II or III)by intestinal r SO2 was 52.70%,and the sensitivity,specificity and area under the curve were 53.0%,96% and 81.5% respectively.The best cutoff value of intestinal r SO2 in the diagnosis of NEC(Bell II or III)was 50.9%,and the sensitivity,specificity and area under the curve were 95.3%,90.0% and 96.3%,respectively.Conclusion: 1.NIRS monitoring of neonatal intestinal r SO2 and THI results showed that compared to suspected or non NEC patients,diagnosed NEC patients showed lower levels,which can be used as a useful tool for early detection and differentiation of severity of NEC.2.When the intestinal r SO2 is below 52.70%,the occurrence of NEC should be suspected,and when it is below 50.9%,the progression of NEC should be highly suspected.