Carbon Dioxide Versus Air Insufflation for Elective Colonoscopy: A Meta-Analysis and Systematic Review of Randomized Controlled Trials. Surg Laparosc Endosc Percutan Tech. 2016;26:102-116. [PMID: 26841319 DOI: 10.1097/SLE.0000000000000243]

Investigation of the relationship between colonoscopy insertion difficulty factors and endoscope shape using an endoscopic position detection unit

In this study, we investigated the relationship between the cecal intubation time (CIT) and the form and method used for passing through the sigmoid/descending colon junction (SDJ) and the hepatic flexure using an endoscopic position detection unit (UPD), with reference to various factors [age, sex, body mass index (BMI), history of abdominal and pelvic surgery, and diverticulum]. A total of 152 patients underwent colonoscopy with UPD. The mean age was 66.9 ± 12.4 years, and the male to female ratio was 3.6:1. The average CIT time was 14.3 ± 8.2 min. Age, number of experienced endoscopies, history of abdominal and pelvic surgery, BMI, and diverticulum were associated with prolonged CIT; SDJ passage pattern was straight: 8.6 ± 5.0, alpha loop: 11.8 ± 5.6, puzzle ring-like loop: 20.2 ± 5.0, reverse alpha loop: 22.4 ± 9.7, and other loop: 24.7 ± 10.5. The hepatic flexure passing method was in the following order: right rotation maneuver: 12.6 ± 6.6, push maneuver: 15.1 ± 5.9, and right rotation with positional change maneuver: 20.5 ± 7.2. In conclusion, colonoscopy with UPD revealed an association between CIT and SDJ passage pattern and hepatic flexure passing method.

Carbon dioxide insufflation reduces the relapse of ulcerative colitis after colonoscopy: A randomized controlled trial

BACKGROUND AND AIM

Colonoscopy is necessary for diagnosing and surveilling patients with ulcerative colitis, though it may cause disease flares. Colonoscopy with carbon dioxide (CO2) insufflation decreases abdominal discomfort; however, its effect on exacerbation incidence in ulcerative colitis remains unclear. Therefore, this study aimed to evaluate the colonoscopy effects using CO2 insufflation in patients with ulcerative colitis.

METHODS

Overall, 96 remissive patients with ulcerative colitis (partial Mayo score ≤ 2) who underwent total colonoscopy between March 2015 and December 2019 at Osaka University Hospital were enrolled and blindly randomized to the CO2 (n = 45) and air (n = 51) insufflation group (UMIN-CTR, number: UMIN000018801). The post-procedural abdominal discomfort and the clinical relapse (partial Mayo score ≥ 3) rate within 8 weeks were evaluated.

RESULTS

Baseline backgrounds did not differ between the groups. The mean abdominal fullness and pain scores were significantly lower in the CO2 group than in the Air group immediately (p = 0.0003, p = 0.0003) and 30 min (p < 0.0001, p < 0.0001) after colonoscopy. While the overall clinical relapse rate remained unchanged between the groups, the clinical relapse rate at 8 weeks after colonoscopy was significantly lower in the CO2 group than in the Air group in patients not in complete remission (Mayo endoscopic subscore ≥ 1, p = 0.049; or partial Mayo score ≥ 1, p = 0.022).

CONCLUSIONS

CO2 insufflation can reduce abdominal discomfort in remissive patients with ulcerative colitis and decrease clinical relapse at 8 weeks after colonoscopy for those not in complete remission.

Investigation of the New Advantages of Colonoscope Insertion with an Endoscopic Position Detection Unit

BACKGROUND

The use of an endoscopic position detection unit (UPD) enables better and more objective understanding of the shape and position of the colonoscope. Here, we investigated the reproducibility of the insertion of a colonoscope with UPD.

MATERIALS AND METHODS

Study participants were 122 patients who received a colonoscopy with UPD twice for the purpose of large bowel screening and surveillance. The mean age of participants was 69.7 ± 10.4 years, and the male-to-female ratio was 9.2:1. The colonoscope insertion technique was primarily based on the shaft-holding, shortening insertion method. The cecal intubation time was recorded; the method used for passing through the sigmoid/descending colon junction (SDJ) and the hepatic flexure.

RESULTS

The mean cecal intubation time was 990 ± 511 s. The cecal intubation time and the patterns for passing through the SDJ and hepatic flexure were significantly correlated between the first and second colonoscopies.

CONCLUSION

Use of a UPD revealed good reproducibility of colonoscope insertion. This is the first time we have proved that both time and pattern are inserted in much the same way for the first and second times. In patients' conducted UPD combination TCS after the second time, it was suggested that individual tailor-made insertions are possible based on the information from the first time.

Practical considerations for colorectal cancer screening in older adults

Recent guidelines recommend that colorectal cancer (CRC) screening after age 75 be considered on an individualized basis, and discourage screening for people over 85 due to competing causes of mortality. Given the heterogeneity in the health of older individuals, and lack of data within current guidelines for personalized CRC screening approaches, there remains a need for a clearer framework to inform clinical decision-making. A revision of the current approach to CRC screening in older adults is even more compelling given the improvements in CRC treatment, post-treatment survival, and increasing life expectancy in the population. In this review, we aim to examine the personalization of CRC screening cessation based on specific factors influencing life and health expectancy such as comorbidity, frailty, and cognitive status. We will also review screening modalities and endoscopic technique for minimizing risk, the risks of screening unique to older adults, and CRC treatment outcomes in older patients, in order to provide important information to aid CRC screening decisions for this age group. This review article offers a unique approach to this topic from both the gastroenterologist and geriatrician perspective by reviewing the use of specific clinical assessment tools, and addressing technical aspects of screening colonoscopy and periprocedural management to mitigate screening-related complications.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

Insufflation of Carbon Dioxide versus Air During Colonoscopy Among Pediatric Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background/Aims:

Carbon dioxide is increasingly used in insufflation during colonoscopy in adult patients; however, air insufflation remains the primary practice among pediatric gastroenterologists. This systematic review and meta-analysis aims to evaluate insufflation using CO₂ versus air in colonoscopies in pediatric patients.

Methods:

Individualized search strategies were performed using MEDLINE, Cochrane Library, EMBASE, and LILACS databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and Cochrane working methodology. Randomized control trials (RCTs) were selected for the present meta-analysis. Pooled proportions were calculated for outcomes including procedure time and abdominal pain immediately and 24 hours post-procedure.

Results:

The initial search yielded 644 records, of which five RCTs with a total of 358 patients (CO₂: n=178 versus air: n=180) were included in the final analysis. The procedure time was not different between the CO₂ and air insufflation groups (mean difference, 10.84; 95% confidence interval [CI], -2.55 to 24.22; p=0.11). Abdominal pain immediately post-procedure was significantly lower in the CO₂ group (risk difference [RD], -0.15; 95% CI; -0.26 to -0.03; p=0.01) while abdominal pain at 24 hours post-procedure was similar (RD, -0.05; 95% CI; -0.11 to 0.01; p=0.11).

Conclusions:

Based on this systematic review and meta-analysis of RCT data, CO₂ insufflation reduced abdominal pain immediately following the procedure, while pain was similar at 24 hours post-procedure. These results suggest that CO₂ is a preferred insufflation technique when performing colonoscopy in pediatric patients.

Carbon Dioxide vs. Air Insufflation for Pediatric Gastrointestinal Endoscopy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Carbon dioxide (CO2) insufflation during gastrointestinal (GI) endoscopic procedures has gained popularity in adults. However, its utility in pediatric patients is not known. The current review aimed to compare the efficacy of CO2 vs. air insufflation for GI endoscopic procedures in pediatric patients. Methods: The electronic databases of PubMed, Embase, Scopus, and CENTRAL were searched from the inception of databases to 15th August 2020. Results: All randomized controlled trials (RCTs) comparing CO2 vs. air insufflation for GI endoscopic procedures in pediatric patients were eligible for inclusion. Five RCTs were identified. Pooled analysis of data from 226 patients in the CO2 group and 224 patients in the air group revealed that patients receiving CO2 insufflation were at a lower odds of experiencing postoperative pain as compared to those undergoing the procedure with air (OR: 0.40; 95% CI: 0.19, 0.87; I 2 = 62%; p = 0.02). Descriptive analysis indicated no difference in the two groups for abdominal distention after the procedure. Two trials reported elevated CO2 in the study group but without any pulmonary complications. Bloating was reported by two studies and both reported significantly less bloating in the CO2 group. Conclusion: Our study indicates that the incidence of pain may be reduced with the use of CO2 insufflation in pediatric GI endoscopies without a significant risk of adverse events. However, current evidence is from a limited number of trials and not strong to recommend a routine of CO2 in pediatric gastroenterology practice. Further high-quality RCTs are required to supplement current evidence.

Is Carbon Dioxide Insufflation During Endoscopy in Children as Safe and as Effective as We Think?

OBJECTIVES

Distension of the gastrointestinal lumen is crucial for visualization and advancement during endoscopic procedures. An increasing number of pediatric centers now use carbon dioxide (CO2) preferentially over air as many adult studies and a few pediatric studies have concluded that CO2 is better tolerated than air, especially for colonoscopy.

AIMS

The aim of the study was to determine if CO2 is as safe and as effective as air and if it reduces abdominal discomfort and distension in children undergoing upper endoscopy and colonoscopy.

METHODS

Double blinded, prospective, randomized clinical study. Patient- and nursing-reported outcomes of pain and distension were recorded. End tidal CO2 (EtCO2) was monitored continuously with a CO2-sampling nasal cannula for patients undergoing procedural sedation and via the endotracheal tube for those who were intubated.

RESULTS

One hundred seventy-eight patients with 180 procedures were enrolled, 91 procedures were randomized to receive CO2, and 89 to air. Groups did not differ significantly with respect to nursing-assessed abdominal discomfort, change in girth from baseline, or endoscopist-perceived ease of inflation. Use of CO2 was associated with transient spikes in the EtCO2 (≥60 mmHg) in a significant number of patients during sedated upper endoscopy without endotracheal intubation. There was a reduction of bloating and flatulence for all procedures in the CO2 group.

CONCLUSIONS

The benefits of using CO2 for insufflation were minimal in our patients. The observed transient elevations of EtCO2 during sedated upper endoscopy raise concerns of possible systemic hypercarbia. The wisdom of its routine use for all pediatric endoscopic procedures is questioned.

Efficacy and Safety of Carbon Dioxide Versus Air Insufflation for Colonoscopy in Deeply Sedated Pediatric Patients

OBJECTIVES

Studies have shown the advantages of carbon dioxide (CO2) over air insufflation in the adult population during colonoscopies. This study was designed to investigate the efficacy and safety of CO2 insufflation in deeply sedated children undergoing colonoscopy.

METHODS

This was a prospective, randomized, double-blind clinical trial. We recruited 100 consecutive pediatric patients who had colonoscopy under deep sedation for various indications. Patients were first randomized by history of abdominal pain and then randomly assigned to either CO2 or air insufflation. Postprocedural abdominal pain scores were registered on a 10-point visual analog rating scale and significant pain was defined as a score of 3 or higher. Abdominal circumferences and end tidal CO2 (ETCO2) levels were measured. Complications during and after the procedure were recorded.

RESULTS

We did not find statistically significant difference between CO2 and air insufflation on univariate analysis because of low number of children experiencing significant pain after colonoscopy. After adjusting for baseline pain, we found that pain was significantly lower in patients after CO2 versus air insufflation on multivariable analysis (P = 0.03). The significant factors related to pain were duration of the procedure (P = 0.006), history of abdominal pain (P = 0.002) and previous abdominal surgery (P = 0.02). CO2 insufflation was associated with decreased abdominal circumference after colonoscopy (P = 0.002). Girls were more likely to have pain regardless of intervention (P = .04).

CONCLUSIONS

Most children tolerate endoscopic procedures without significant pain. Our study was underpowered to show significant difference between air and CO2 on univariate analysis. CO2 insufflation during colonoscopy, however, may reduce postprocedural abdominal pain. Significant factors for increased pain on multivariate analysis included colonoscopy length over 30 minutes, history of abdominal pain, and previous abdominal surgery.

Optimal sequences of same-visit bidirectional endoscopy: Systematic review and meta-analysis

BACKGROUND AND AIM

Same-visit colonoscopy and esophagogastroduodenoscopy (EGD) have become common. Recent studies showed conflicting results regarding the performance, safety, and efficacy of different sequences. We conducted this meta-analysis to determine the most favorable performance and discomfort between an EGD followed by colonoscopy (E-C) and colonoscopy followed by EGD (C-E).

METHODS

The authors searched the databases of MEDLINE and EMBASE. Outcomes of interest were performance (including cecal intubation time, adenoma detection rate, and polyp detection rate), discomfort score (patients and endoscopists; Likert scale), and sedation uses. Pooled mean differences (MD) or odds ratios (OR) were calculated with 95% confidence intervals (CI).

RESULTS

Six randomized controlled trials were included in the meta-analysis. The authors found that there was significantly lower sedative use including fentanyl (14.70; 95% Cl: 8.20-21.20) and propofol (15.58; 95% Cl: 3.27-27.89) in the E-C group compared with the C-E group. There was a significantly better discomfort score in patients and endoscopists after both procedures in the E-C group than in the C-E group with pooled MD of 0.64 points (95% Cl: 0.09-1.20) and 0.47 (95% Cl: 0.05-0.90), respectively. There were no differences in cecal intubation time, adenoma detection rate, or polyp detection rate between the two groups.

CONCLUSION

The present study found that the discomfort score was better in the E-C group. However, there was no difference in polyp and adenoma detection. Therefore, the E-C group is the optimal sequence.

Propofol versus midazolam with or without short-acting opioids for sedation in colonoscopy: a systematic review and meta-analysis of safety, satisfaction, and efficiency outcomes

BACKGROUND AND AIMS

Propofol is increasingly being used for sedation in colonoscopy; however, its benefits over midazolam (± short-acting opioids) are not well quantified. The objective of this study was to compare safety, satisfaction, and efficiency outcomes of propofol versus midazolam (± short-acting opioids) in patients undergoing colonoscopy.

METHODS

We systematically searched Medline, Embase, and the Cochrane library (to July 30, 2018) for randomized controlled trials of colonoscopies performed with propofol versus midazolam (± short-acting opioids). We pooled odds ratios for cardiorespiratory outcomes using mixed-effects conditional logistic models. We pooled standardized mean differences (SMDs) for patient and endoscopist satisfaction and efficiency outcomes using random-effects models.

RESULTS

Nine studies of 1427 patients met the inclusion criteria. There were no significant differences in cardiorespiratory outcomes (hypotension, hypoxia, bradycardia) between sedative groups. Patient satisfaction was high in both groups, with most patients reporting willingness to undergo a future colonoscopy with the same sedative regimen. In the meta-analysis, patients sedated with propofol had greater satisfaction than those sedated with midazolam (± short-acting opioids) (SMD, .54; 95% confidence interval [CI], .30-.79); however, there was considerable heterogeneity. Procedure time was similar between groups (SMD, .15; 95% CI, .04-.27), but recovery time was shorter in the propofol group (SMD, .41; 95% CI, .08-.74). The median difference in recovery time was 3 minutes, 6 seconds shorter in patients sedated with propofol.

CONCLUSIONS

Both propofol and midazolam (± short-acting opioids) result in high patient satisfaction and appear to be safe for use in colonoscopy. The marginal benefits to propofol are small improvements in satisfaction and recovery time.

A meta-analysis of carbon dioxide versus room air insufflation on patient comfort and key performance indicators at colonoscopy

BACKGROUND

Carbon dioxide (CO₂) has been used as an alternative to air insufflation at endoscopy with good results; however, uptake of the technique has been poor, possibly due to perceived lack of outcome equivalency. This meta-analysis evaluates the effectiveness of CO₂ versus air in reducing pain post-colonoscopy and furthermore examines other key performance indicators (KPIs) such as sedative use, procedure times and polyp detection rates.

METHODS

This meta-analysis was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Pubmed, Pubmed Central, Embase and Cochrane Library were searched for randomized studies from 2004 to 2019, reporting outcomes for patients undergoing colonoscopy with air or CO₂ insufflation, who reported pain on a numerical or visual analogue scale (VAS). Results were reported as mean differences (MD) or pooled odds ratios (OR) with 95% confidence intervals (95% CI).

RESULTS

Of 3586 citations, 23 studies comprising 3217 patients were analysed. Patients undergoing colonoscopy with air insufflation had 30% higher intraprocedural pain scores than those receiving CO₂ (VAS 3.4 versus 2.6, MD -0.7, 95% CI - 1.4-0.0, p = 0.05), with a sustained beneficial effect amongst those in the CO₂ group at 30 min, 1-2-h and 6-h post procedure (MD - 0.8, - 0.6 and - 0.2, respectively, p < 0.001 for all), as well as less distension, bloating and flatulence (p < 0.01 for all). There were no differences between the two groups in KPIs such as the sedation required, procedure time, caecal intubation or polyp detection rates.

CONCLUSIONS

CO₂ insufflation improves patient comfort without compromising colonoscopic performance.

Practice recommendations for the use of sedation in routine hospital-based colonoscopy

Objective

Although sedation improves patient experience during colonoscopy, there is great jurisdictional variability in sedative practices. The objective of this study was to develop practice recommendations for the use of moderate and deep sedation in routine hospital-based colonoscopy to facilitate standardisation of practice.

Design

We recruited 32 multidisciplinary panellists to participate in a modified Delphi process to establish consensus-based recommendations for the use of sedation in colonoscopy. Panel members participated in a values assessment survey followed by two rounds of anonymous online voting on preliminary practice recommendations. An inperson meeting was held between voting rounds to facilitate consensus-building. Consensus was defined as >60% agreement/disagreement with recommendation statements; >80% agreement/disagreement was considered indicative of strong consensus.

Results

Twenty-nine panellists participated in the values assessment survey. Panellists ranked all factors presented as important to the development of practice recommendations. The factor considered most important was patient safety. Patient satisfaction, procedural efficiency, and cost were considered less important. Strong consensus was achieved for all nine practice recommendations presented to the panel. These recommendations included that all endoscopists be able to perform colonoscopy with moderate sedation, that an endoscopist and a single trained nurse are sufficient for performing colonoscopy with moderate sedation, and that anaesthesia-provided deep sedation be used for select patients.

Conclusion

The recommendations presented in this study were agreed on by a multidisciplinary group and provide guidance for the use of sedation in routine hospital-based colonoscopy. Standardised sedation practices will promote safe, effective, and efficient colonoscopy for all patients.

ASGE review of adverse events in colonoscopy

Colonoscopy is the most commonly performed endoscopic procedure and overall is considered a low-risk procedure. However, adverse events (AEs) related to this routinely performed procedure for screening, diagnostic, or therapeutic purposes are an important clinical consideration. The purpose of this document from the American Society for Gastrointestinal Endoscopy's Standards of Practice Committee is to provide an update on estimates of AEs related to colonoscopy in an evidence-based fashion. A systematic review and meta-analysis of population-based studies was conducted for the 3 most common and important serious AEs (bleeding, perforation, and mortality). In addition, this document includes an updated systematic review and meta-analysis of serious AEs (bleeding and perforation) related to EMR and endoscopic submucosal dissection for large colon polyps. Finally, a narrative review of other colonoscopy-related serious AEs and those related to specific colonic interventions is included.

Carbon dioxide versus room air for colonoscopy in deeply sedated pediatric patients: a randomized controlled trial

Background and study aims  Use of carbon dioxide (CO ₂ ) instead of room air (RA) during colonoscopy in adults revealed significantly less flatulence and abdominal pain in several studies. The objectives of this study were to investigate the effects of CO ₂ usage on post-interventional pain, abdominal discomfort, abdominal girth, pCO ₂ levels, and narcotic requirement in deeply sedated pediatric patients. Patients and methods  A total of 97 children and adolescents aged 4 years to 17 years undergoing colonoscopy were randomized to RA or CO ₂ in a prospective, randomized, controlled trial. Age-appropriate pain scales assessed abdominal pain as primary outcome. In addition, abdominal girth, abdominal bloating, transcutaneous pCO ₂ , narcotic requirement to achieve deeply sedation, and post-procedural analgesic demand was analyzed in 73 patients. Results  Overall, significantly fewer patients reported bloating in the CO ₂ group ( P  = 0.0012). However, we observed only a trend to lower post-interventional pain ( P  = 0.15) and a lower pain score. There was no significant difference in transcutaneous pCO ₂ level and no adverse events occurred. Although there was no difference in the dosage of propofol and midazolam, we observed a significant increased necessity for use of synthetic opioids in the RA group to achieve optimal examination conditions ( P  = 0.023). Conclusions  The benefits using CO ₂ in colonoscopy of deeply sedated children predominate. In particular, CO ₂ insufflation may allow a less painful post-interventional time and it significantly reduces abdominal bloating. Moreover, with CO ₂ , significantly less additional opioids were used. Thus, CO ₂ insufflation can be considered as safe in deeply sedated patients as there was no relevant pulmonary CO ₂ retention observed. (DRKS00013914).

Carbon Dioxide Insufflation Increases Colonoscopic Adenoma Detection Rate Compared With Air Insufflation

GOALS

To determine the effect of carbon dioxide insufflation on the most important outcome measure of colonoscopic quality: adenoma detection rate (ADR).

BACKGROUND

Bowel cancer is the second most common cause of cancer deaths in males and females in Australia. Carbon dioxide has in recent times become the insufflation methodology of choice for screening colonoscopy for bowel cancer, as this has been shown to have significant advantages when compared with traditional air insufflation.

STUDY

Endoscopies performed over a period of 9 months immediately before and after the implementation of carbon dioxide insufflation at endoscopy centers were eligible for inclusion.

RESULTS

The difference in ADR between the carbon dioxide and air insufflation methods was statistically significant, with an increased ADR in the carbon dioxide group. The superiority of carbon dioxide insufflation was sustained with a logistic regression model, which showed ADR was significantly impacted by insufflation method.

CONCLUSIONS

Carbon dioxide insufflation is known to reduce abdominal pain, postprocedural duration of abdominal pain, abdominal distension, and analgesic requirements. This study represents for the first time the beneficial effect of carbon dioxide insufflation upon the key quality colonoscopy indicator of ADR.

Insufflation With Carbon Dioxide During Pediatric Colonoscopy for Control of Postprocedure Pain

GOALS

To determine if carbon dioxide (CO2) insufflation in children would improve postprocedure pain following colonoscopy in children.

BACKGROUND

CO2 insufflation during colonoscopy has been found to reduce postcolonoscopy pain in the adult population, but limited data exist in pediatrics.

MATERIALS AND METHODS

We conducted a prospective study with 40 pediatric patients scheduled for outpatient colonoscopy. Patients were enrolled continuously and were randomized to receive CO2 or air insufflation. Patients and colonoscopists were blinded to insufflation method. End tidal CO2 (EtCO2) was documented throughout the procedure. Abdominal pain was established preprocedure then at 1-, 6-, and 24-hour postprocedure. Subject demographics, indications, colonoscopists' year of training, time to cecum, adverse events, and final diagnoses were recorded.

RESULTS

Twenty patients were randomized to each group. Patients receiving air had a statistically significant increase in pain from baseline at 1- and 6-hours after colonoscopy (P=0.007 and 0.008). This was not seen in the CO2 group (P=0.740 and 0.289). There was an increase in postprocedure pain in the air group compared with CO2 group at the 1-hour mark (P=0.032). EtCO2 increased during the procedure, regardless of insufflation method, but no difference was seen between groups (P=0.822).

CONCLUSIONS

Our results demonstrate that higher levels of pain were reported by patients following air compared with those receiving CO2 insufflation. This is the first study to show CO2 is as safe as air, with no increase in EtCO2 between groups in the pediatric population. CO2 is an effective and safe modality and should be considered for pediatric colonoscopies.

Is water exchange superior to water immersion in detecting adenomas during colonoscopies? Results from a Bayesian network meta-analysis

AIM

Water-assisted colonoscopy (water exchange [WE] and water immersion [WI]) has been shown to improve the adenoma detection rate. However, few studies have compared these two methods head-to-head. Thus, we conducted a network meta-analysis to integrate both direct and indirect evidence comparing the effectiveness of these two procedures.

METHOD

We searched PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials for original papers and abstracts published up to March 2018. Randomized controlled trials (RCTs) reporting data in accordance with the eligibility criteria were included in this study. We performed a Bayesian random effects network meta-analysis with mixed comparisons.

RESULTS

Twenty-nine studies (n = 11464 patients) including 6 direct and 23 indirect comparisons were included in this network meta-analysis. There was a statistically significant difference in the efficacy of adenoma detection when WE was compared with WI (risk ratio [RR]: 1.2, 95% credible interval [CrI]: 1.1-1.3), air insufflation (AI; RR: 1.3, 95% CrI: 1.1-1.4), and carbon dioxide (CO2) insufflation (RR: 1.2, 95% CrI: 1.1-1.5). The different methods were ranked in order from the most to least effective in adenoma detection as follows: WE, WI, AI, and CO2. Moreover, although there were no significant differences in pain scores, willingness to repeat, caecal intubation rate, or total procedure time between WI and WE colonoscopy, WE required a longer caecal intubation time than WI.

CONCLUSION

This network meta-analysis supposes that WE may be superior to WI in detecting adenomas during colonoscopies without affecting other technical features or patient acceptance.

Carbon dioxide insufflation during endoscopic resection of large colorectal polyps can reduce post-procedure abdominal pain: A prospective, double-blind, randomized controlled trial

Background

Studies of the use of CO₂ insufflation during endoscopic resection of large colorectal polyps (LCPs) are lacking.

Objective

We evaluated the effect of CO₂ insufflation on pain after endoscopic resection of LCPs.

Methods

In a prospective randomized controlled trial (RCT), 132 patients were randomly assigned to groups who underwent endoscopic resection with CO₂ insufflation (CO₂ group, n = 66) or air insufflation (air group, n = 66). The primary outcome was abdominal pain post-procedure (PP). The secondary outcomes were abdominal distension, rates of technical success, amounts of sedatives prescribed, use of analgesics, and adverse events.

Results

Baseline patient characteristics were similar between the groups. The mean abdominal pain score was 12.3 in the CO₂ group vs. 17.5 in the air group at 1 h PP (p  =  0.047). Also, the proportion of patients without pain was significantly higher in the CO₂ group at 1 h PP (p = 0.008). The pain score differed more in the endoscopic submucosal dissection group and long-time group. The secondary outcomes were not significantly different between the two groups.

Conclusions

The results of this RCT demonstrate the superiority of CO₂ insufflation for endoscopic resection of LCPs in terms of decreasing PP abdominal pain (KCT0001636).

Bayesian network meta-analysis: Efficacy of air insufflation, CO2 insufflation, water exchange, and water immersion in colonoscopy

BACKGROUND AND AIM

Colonoscopy is an excellent screening tool for colorectal cancer. There are four colonoscopy techniques: air insufflation, CO₂ insufflation, water exchange, and water immersion. Some studies reported that the latter three methods are better than the criterion standard (air insufflation), whereas some studies did not. In order to evaluate the efficacy of the four colonoscopy techniques, a network meta-analysis was carried out.

METHODS

We searched randomized controlled trials (RCT) published up to September 2017 from PubMed, Embase, Cochrane library, and Web of Science. Studies referencing the comparison between at least two of air insufflation, CO₂ insufflation, water exchange, and water immersion were selected. Primary outcomes included pain score during insertion, polyp detection rate, and adenoma detection rate, and secondary outcomes included cecal intubation time and cecal intubation rate. Mean differences or odds ratios and their corresponding 95% credible intervals were pooled with Bayesian modeling.

RESULTS

Forty RCT with 13 734 patients were included in this network meta-analysis. Our analysis showed that air insufflation had the highest pain score (surface under the cumulative ranking curve [SUCRA]: 98.8%) and the lowest detection rate of adenoma (SUCRA: 21.3%) and polyp (SUCRA: 16.8%). Water exchange had the lowest pain score (SUCRA: 1.1%) and highest detection rate of adenoma (SUCRA: 96.0%) and polyp (SUCRA: 98.9%), although it led to the longest cecal intubation time (SUCRA: 86.9%).

CONCLUSIONS

Air insufflation might be the most unsatisfactory colonoscopy. Meanwhile, water exchange might be the most efficient colonoscopy.

Comparison of carbon dioxide and air insufflation during consecutive EGD and colonoscopy in moderate-sedation patients: a prospective, double-blind, randomized controlled trial

BACKGROUND AND AIMS

Endoscopy is performed with air insufflation and is usually associated with abdominal pain. It is well recognized that carbon dioxide (CO₂) is absorbed more quickly into the body than air; however, to date, few studies have investigated the use of CO₂ insufflation during consecutive EGD and colonoscopy (CEC). Thus, this study evaluated the efficacy of CO₂ insufflation compared with air insufflation in CEC.

METHODS

From March 2014 to April 2016, a total of 215 consecutive patients were randomly assigned to receive CO₂ insufflation (CO₂ group, n = 108) or air insufflation (air group, n = 107). Abdominal pain after CEC was recorded on a visual analogue scale (VAS). The amount of sedatives administered, use of analgesics, polyp detection rate (PDR), adenoma detection rate (ADR), abdominal circumference, and adverse events were also analyzed.

RESULTS

Baseline patient characteristics were not significantly different between the groups. Abdominal pain on the VAS in the CO₂ group and air group 1 hour after CEC was, respectively, 13.8 and 20.1 (P = .010), 3 hours after CEC was 8.3 and 12.5 (P = .056), 6 hours after CEC was 3.5 and 5.3 (P = .246), and 1 day after CEC was 1.8 and 3.4 (P = .192). The dose of sedative administered, analgesic usage, PDR, ADR, and adverse events were not statistically different between the groups. However, the increase in abdominal circumference was significantly higher in the air group than in the CO₂ group.

CONCLUSIONS

CO₂ insufflation was superior to air insufflation with regard to the pain score on the VAS in the hour after CEC. (Clinical trial registration number: KCT0001491.).

Carbon dioxide insufflation during colonoscopy in inflammatory bowel disease patients: a double-blind, randomized, single-center trial

OBJECTIVE

Bowel distension by insufflated air causes abdominal discomfort after colonoscopy. Carbon dioxide (CO2) instead of air insufflation during colonoscopy can reduce postprocedural discomfort in diagnostic and screening cases. Discomfort after colonoscopy and CO2 insufflation have never been studied in inflammatory bowel disease (IBD) patients, characterized by younger age, structural changes of the colon, and need for repeated and frequently uncomfortable colonoscopies. Our trial was designed to evaluate postprocedural discomfort associated with CO2 compared with air insufflation in unsedated or minimally sedated patients with known IBD.

METHODS

In a double-blind, randomized, single-center study, 64 patients were randomized to either CO2 insufflation (CO2) or air insufflation colonoscopy (Air). Abdominal pain, bloating, and flatulence scores during 24 h after colonoscopy were recorded using a continuous scale of 0-10 (0=none, 10=maximum discomfort). The primary endpoint used for power calculation was bloating score at 1 h after colonoscopy.

RESULTS

Pain, bloating, and flatulence scores at end, 1, and 3 h after colonoscopy were significantly lower in CO2 than in Air arm (P<0.001). Scores at 6, 12, and 24 h were comparable. Procedural parameters such as cecal and terminal ileum intubation rate, intubation and total time, pain during insertion, need for repositioning, and abdominal compression were not different between arms. No complications were recorded in the study.

CONCLUSION

Compared with air, CO2 insufflation significantly reduces abdominal pain, bloating, and flatulence scores during at least 3 h after colonoscopy in IBD patients, achieving comparable intraprocedural outcomes.

Painless Colonoscopy: Available Techniques and Instruments

During colonoscopy, air insufflation to distend the lumen and facilitate careful inspection and scope insertion can induce pain and cause discomfort. Carbon dioxide (CO₂) insufflation can decrease abdominal pain and discomfort during and after colonoscopy. The advantage of CO₂ insufflation is the rapid absorption of the gas across the intestine. Another painless option is water-assisted colonoscopy. Two methods for water-assisted colonoscopy are available: water immersion and water exchange. In a recent direct comparison, the water exchange method was superior to water immersion, CO₂ insufflation, and air insufflation with respect to pain during colonoscopy, although it still had the disadvantage of being a time-consuming procedure. Cap-assisted colonoscopy is a simple technique involving the use of a small transparent cap attached to the tip of the scope. Three studies showed an advantage of this technique in terms of reduced patient discomfort compared with the conventional method. Three robotic colonoscopy systems (Endotics System [Era Endoscopy], NeoGuide [NeoGuide Systems Inc.], and Invendoscope [Invendo Medical]) have been introduced to evaluate pain reduction during colonoscopy, but none has been widely adopted and used in practice. In this review, clinical trials of several techniques and new devices for painless colonoscopy are described and summarized.

Diagnosis and treatment of ischemic colitis

Ischemic colitis (IC) is a common reason of acute lower gastrointestinal bleeding, and it is frequently seen in elderly people. In recent years, both the incidence and prevalence of IC have been rising. Most episodes of IC are transient and self-limited and only a minority of cases are severe. IC often has missed and delayed diagnosis. This review mainly focuses on the progress in the understanding of the diagnosis and therapy of IC.