Study On The Application Of Antifoaming Agents In Bowel Preparation Before Small Bowel Capsule Endoscopy Examination

Background:Small bowel capsule endoscopy(SBCE)examination spreads widely in intestinal diseases diagnosis due to its high safety,no pain,no cross infection,and high diagnostic rate in clinical application.Liquid/semi-liquid diet,fasting,taking laxative are adopted in turns successively to improve efficiency of bowel preparation,using defoaming agents may raise the bowel preparation quality effectively.Simethicone and dimethicone powder are both the popular defoaming agents.recommended dose of simethicone is not inconsistent in different guidelines,and in which is not refer to dimethicone powder.There are controversies about whether increasing cleaning,diagnosis rate and complete rate,reducing bubbles in digestive tract effectively in some studies.Further study should be taken to confirm that in safety,efficiency,optimal dose,best time about the using of defoaming agents in bowel preparation before SBCE examination.Objective:1.Multiple randomized control trial:To compare the effect of dimethicone powder at different dose and explore the recommended dose in bowel preparation before SBCE examination.2.Meta-analysis:Assessing the necessity,optimal dose and best time in bowel preparation before SBCE systematically.Methods:1.Multiple randomized control trial:132 people were randomly divided into 3 parts by 1:1:1 with evenly 44 cases in each group from a multicenter randomized control trial around May 2016 to January 2019 in 4 hospitals.All patients take 2 liters of polyethylene glycol(PEG)solution orally 6 h before the examination,and then drink 100 m L pure water in control group(group A),2.5 g and 5 g in 100 m L dimethicone powder solution in test group 1(group B)and test group 2(group C)respectively.The evaluation indicators including small bowel bubble quantity(SBBQ),small bowel bubble valid picture ratio(SBBVPR),small bowel bubble good picture ratio(SBBGPR),small bowel bubble excellent picture ratio(SBBEPR),small bowel cleaning quality(SBCQ),gastric bubble quantity(GBQ),gastric cleaning quantity(GCQ),complete rate(CR),diagnostic yield(DY),small bowel transit time(SBTT)and gastric transit time(GTT).Using the software SPSS(version 22.0)to conduct statistical analysis with one-way ANOVA,rank sum test,χ~2test,Fisher’s precision probability test.2.Meta-analysis:The literature was searched from Chinese database including CNKI,VIP,Wang Fang data,CBM,and English database including Cochrane Library,Pubmed,EMbase,Web of Science,respectively followed the instruction of Cochrane system reviewer’s handbook(version 5.1.0)guidance strictly,that published from database setup to December,2021.Searching the subject heading including capsule endoscopy,capsule endoscopes,antifoaming agents,simethicone,dimeticone,randomized controlled trial,random allocation in Chinese and English database respectively.Using software Rev Man(version 5.2)and Stata(version 17.0)to analyze the data extracted after being filtered by inclusion criteria and literature quality evaluation.Results:1.Multiple randomized control trial:132 patients are involved in 4 hospitals from May 2016 to January 2019.The median of SBBQ in group A was higher than group B and group C(proximal:1.564 vs 0.574 vs 0.540,middle:1.370 vs 0.473 vs 0.651,distal:1.737 vs0.906 vs 0.654,whole:1.967 vs 0.775 vs 0.718)in corresponding segments on small bowel,however the contrary is the case in SBBVRP(proximal:92.0%vs 97.5%vs 97.0%,middle:91.8%vs 99.0%vs 98.0%,distal:90.2%vs 96.1%vs 98.0%,whole:90.1%vs 97.7%vs97.3%),SBBGRP(proximal:79.0%vs 92.0%vs 91.5%,middle:98.4%vs 94.0%vs 88.6%,distal:79.7%vs 87.7%vs 91.2%,whole:72.6%vs 88.4%vs 88.8%)and SBBERP(proximal:58.0%vs7 6.0%vs 84.4%,middle:52.5%vs 82.2%vs 77.6%,distal:43.1%vs 66.8%vs77.7%,whole:48.1%vs 73.8%vs 78.6%)(P<0.05).And there was no statistical significance between group B and group C(P>0.05).No significant differences were found in rest indicators(P>0.05).2.Meta-analysis:All 34 randomized controlled trials(RCT)are selected in 981 articles which searched in CNKI,VIP,Wang Fang data,CBM,Cochrane Library,Pubmed,EMbase and Web of Science that published from database setup to December,2021,involving 2015patients in antifoaming agents group,1475 patients in control group,3490 patients in total.The Meta-analysis showed that there was significant(P<0.05)difference and the antifoaming agents group was better than control group in the following 6 indicators:SBBQ(MD=0.91,95%CI=0.38～1.45),small bowel bubble qualified picture ratio(SBBQPR)(OR=0.25,95%CI=0.19～0.33),SBBEPR(OR=0.29,95%CI=0.23～0.27),small bowel visualization quality(SBVQ)(MD=0.47,95%CI=0.13～0.81),small bowel visualization qualified picture ratio(SBVQPR)(RR=0.78,95%CI=0.70～0.87),SBCQ(MD=0.19,95%CI=0.03～0.35)andadversereactionratio(ARR)(RR=2.23,95%CI=1.58～3.16),There was no statistical significance in these items(P>0.05):small bowel cleaning good picture ratio(SBCGPR)(RR=0.97,95%CI=0.92～1.02),GTT(RR=0.97,95%CI=0.88～1.07),SBTT(MD=-2.06,95%CI=-8.17～4.05),CR(RR=0.99,95%CI=0.96～1.01),DY RR=0.93,95%CI=0.85～1.01).Network Meta-analysis outcome showed there were same SBBQPR in simethicone and dimethicone when the same active components of antifoaming agents were 300mg(P>0.05).The antifoaming effect have no significant difference among the study that active components of antifoaming is no less than 150mg,the same result in the study that active components of antifoaming is less than150mg compared with blank control group(P>0.05),and the former better than the latter.When the active components of antifoaming is no less than 150mg,taking antifoaming agents30 min or 60 min before examination have the same SBBQPR with that in divided dose(P>0.05),but worse than 45 min before examination,and better than other time before examination(P<0.05).Conclusions:1.Multiple randomized control trial:Dimethicone powder treatment can decrease bubbles efficiently to improve the visibility of small bowel mucosa for bowel preparation before SBCE examination,and the recommended dose of dimethicone powder is 2.5 g than 5g.2.Meta-analysis:According to the Meta-analysis result,using antifoaming agents in bowel preparation before SBCE could effectively reduce bubble and adverse reaction ratio,increase visualization quality and cleaning quantity in small bowel,and have no influence in GTT,SBTT,CR,DY.It had same effect in SBBQPR with simethicone and dimethicone powder when the active components of antifoaming agents were 300mg.The optimal doze of the active components of antifoaming is around 150 mg both in simethicone and dimethicone,it did not improve the antifoaming effect even if raising the doze of antifoaming agents,and the best time to take antifoaming agents is 45 min before examination,30 min or 60 min before examination and in a divided dose are second choose.It needs further exploration by more multicenter,double-blind RCTs to confirm the conclusion above.