Application Of Electrogastrogram In Assessment Of Gastric Motility In Acute Pancreatitis

Background and purposeAcute pancreatitis(AP)is a common critical disease of the digestive system.According to the severity level,severe acute pancreatitis(SAP)is the most serious type,with a mortality rate of up to 30%.Therefore,early prediction of SAP is of great significance for reducing mortality.Studies have shown that gastrointestinal motility disorder is an important cause of AP exacerbation and even death.At present,although there are methods for evaluating gastrointestinal motility disorder,they are difficult to conduct clinically due to various limitations.Electrogastrogram(EGG)is a non-invasive examination that monitors the electrical activity of gastric smooth muscle by placing electrodes on specific body surface positions in the abdomen.Due to its non-invasive,painless,simple and objective features,it has gradually become a clinically emerging way to detect gastric motility.EGG can reflect the existence of gastric motility disorder in many diseases,but the current researches on the application of EGG in AP are limited.This study aims to investigate the value of EGG parameters in assessing the existence of gastric motility disorder in patients with AP and in predicting the severity of acute pancreatitis.Methods1.Participants: We selected AP patients who were diagnosed and treated in Department of Gastroenterology of the First Affiliated Hospital of Nanchang University and meet inclusion and exclusion criteria and healthy volunteers from June 2020 to December 2020.2.The process of EGG examination and parameters collection: Research objects should be in a supine position,and keep quiet and awake during the examination.The abdominal skin where the electrodes were placed should be thoroughly cleaned,and conductive paste were applied to reduce skin impedance.The electrodes were placed according to the instructions of the Dutch MMS gastrointestinal motility examination system,and EGG was recorded in the fasting state for at least 30 minutes.The percentage of normal gastric slow wave,dominant frequency(DF),percentage of gastric tachycardia and percentage of bradycardia were obtained by using EGG analysis software.3.Statistical analysis: Data were analyzed using SPSS 26.0 statistical software.Quantitative data are expressed as mean ± standard deviation(SD)or median(Interquartile range)and analyzed by Student’s t test,Variance analysis or non-parametric test.Categorical data were expressed as frequency(percentage)and analyzed by Chi-square test or Fisher exact test.Correlation analysis was used to analyze the correlation between the parameters.Receiver operating characteristic(ROC)curve was used evaluate the predictive value of EGG parameters for AP severity.A P<0.05 was considered statistically significant.Results1.Baseline characteristics: A total of 83 AP patients and 12 healthy volunteers were enrolled,including 41 mild acute pancreatitis(MAP),36 moderately severe acute pancreatitis(MSAP),and 6 SAP patients.The average age was 46.55±13.36 years old and 57 cases(69.4%)were male.The etiology of AP included gallstones(33.7%),hypertriglyceridemia(37.3%),alcohol consumption(4.8%),Endoscopic Retrograde Cholangiopancreatography(ERCP)surgery(2.4%)and mixed etiology(9.6%).Moreover,10 cases(12.0%)were diagnosed as idiopathic acute pancreatitis(IAP)due to unknown etiology.2.The percentage of normal gastric slow waves in AP patients was significantly lower than that in control group(P<0.05),and the percentage of bradycardia was higher than that in the control group(P<0.05).There was no statistical difference between the AP group and the control group in the average frequency,DF and the percentage of tachycardia(P>0.05).3.The percentage of normal gastric slow waves was negatively correlated with the level of C-reactive protein(CRP)(ρ=﹣0.280,P = 0.01).On the contrary,the percentage of bradycardia was positively correlated with the level of CRP(ρ=0.260,P = 0.017).4.By comparing the EGG parameters of MAP,MSAP and SAP,we found that the average frequency,the percentage of normal gastric slow waves and bradycardia were statistically significant(P<0.05).However,there was no significant difference in DF and the percentage of tachycardia among these three groups.The percentage of normal gastric slow waves and the percentage of bradycardia predicted occurrence of Non-mild acute pancreatitis(N-MAP)with AUC of 0.777(95% CI 0.676-0.877,P<0.001)and 0.775(95% CI 0.67-0.879,P<0.001)respectively.After combining with CRP,the accuracy of predicting N-MAP was improved.The combination of the percentage of normal gastric slow waves and CRP only increased the specificity by4.9%,while both of the sensitivity and specificity were increased with the combination of the percentage of bradycardia and CRP.5.The difference in total scores of gastroparesis cardinal symptom index(GCSI)among MAP、MSAP and SAP groups was statistically significant(P<0.001).GCSI total scores were positively correlated with average frequency(r =-0.232,P = 0.035)and the percentage of normal gastric slow waves(r =-0.355,P = 0.001).On the contrary,there was a positive correlation between GCSI total scores and the percentage of bradycardia(r = 0.374,P<0.001).In conclusion1.EGG could reflect the existence of gastric motility disorders in AP patients.2.There was a correlation between the percentage of normal gastric slow waves,the percentage of bradycardia and CRP.3.The cut-off values of the percentage of normal gastric slow waves and bradycardia for predicting the occurrence of N-MAP were 72.21% and 27.89%,respectively.After being combined with CRP,the accuracy of predicting N-MAP was improved.4.GCSI total scores may be related to the severity of AP.GCSI total scores were correlated with average frequency,the percentage of normal gastric slow waves and bradycardia.