Carbon dioxide insufflation vs conventional air insufflation for colonoscopy: a systematic review and meta-analysis of published randomized controlled trials

Effects of fructooligosaccharides and Saccharomyces boulardii on the compositional structure and metabolism of gut microbiota in students

Fructooligosaccharides (FOS) are a common prebiotic widely used in functional foods. Meanwhile, Saccharomyces boulardii is a fungal probiotic frequenly used in the clinical treatment of diarrhea. Compared with single use, the combination of prebiotics and probiotics as symbiotics may be more effective in regulating gut microbiota as recently reported in the literature. The present study aimed to investigate the effects of FOS, S. boulardii and their combination on the structure and metabolism of the gut microbiota in healthy primary and secondary school students using an in vitro fermentation model. The results indicated that S. boulardii alone could not effectively regulate the community structure and metabolism of the microbiota. However, both FOS and the combination of FOS and S. boulardii could effectively regulate the microbiota, significantly inhibiting the growth of Escherichia-Shigella and Bacteroides, and controlling the production of the gases including H2S and NH3. In addition, both FOS and the combination could significantly promote the growth of Bifidobacteria and Lactobacillus, lower environmental pH, and enhance several physiological functions related to synthesis and metabolism. Nevertheless, the combination had more unique benefits as it promoted the growth of Lactobacillus, significantly increased CO2 production and enhanced the functional pathways of carbon metabolism and pyruvic acid metabolism. These findings provide guidance for clinical application and a theoretical basis for the development of synbiotic preparations.

Bacterial, short-chain fatty acid and gas profiles of partially hydrolyzed guar gum in vitro fermentation by human fecal microbiota

Carbohydrates with different structures have metabolic differences in the human body, as well as individual differences. The present study aimed to investigate the effects of bacterial, short-chain fatty acids (SCFAs) and gas profiles of partially hydrolyzed guar gum (PHGG) on the fecal microbiota of 41 Chinese individuals by simulated fermentation in vitro. Results showed that PHGG stimulated the growth of Bifidobacterium and Faecalibacterium, inhibited the growth of Escherichia-Shigella, Klebsiella, and Dorea, and induced the production of fermentation gases (CO2, and H2) and SCFAs (acetic acid, butyric acid). Furthermore, Bifidobacterium was significantly increased in the young female and the old male-originated samples, while Klebsiella was significantly decreased in the old female ones after PHGG intervention, and there were also certain differences in gases and SCFAs among different population samples. These findings indicate that PHGG can modulate gut microbiota and metabolism well, whereas its use varies in different populations.

Performing High-Quality, Safe, Cost-Effective, and Efficient Basic Colonoscopy in 2023: Advice From Two Experts

Based on published evidence and our expert experience, we provide recommendations to maximize the efficacy, safety, efficiency, and cost-effectiveness of routine colonoscopy. High-quality colonoscopy begins with colon preparation using a split or same-day dose and preferably a low-volume regimen for optimal patient tolerance and compliance. Successful cecal intubation can be achieved by choosing the correct colonoscope and using techniques to facilitate navigation through challenges such as severe angulations and redundant colons. Safety is a primary goal, and complications such as perforation and splenic rupture can be prevented by avoiding pushing through fixed resistance and avoiding loops in proximal colon. Furthermore, barotrauma can be avoided by converting to water filling only (no gas insufflation) in every patient with a narrowed, angulated sigmoid. Optimal polyp detection relies primarily on compulsive attention to inspection as manifested by adequate inspection time, vigorous probing of the spaces between haustral folds, washing and removing residual debris, and achieving full distention. Achieving minimum recommended adenoma detection rate thresholds (30% in men and 20% in women) is mandatory, and colonoscopists should aspire to adenoma detection rate approaching 50% in screening patients. Distal attachments can improve mucosal exposure and increase detection while shortening withdrawal times. Complete resection of polyps complements polyp detection in preventing colorectal cancer. Cold resection is the preferred method for all polyps < 10 mm. For effective cold resection, an adequate rim of normal tissue should be captured in the snare. Finally, cost-effective high-quality colonoscopy requires the procedure not be overused, as demonstrated by following updated United States Multi Society Task Force on Colorectal Cancer postpolypectomy surveillance recommendations.

CO2 Is Beneficial to Gut Microbiota Homeostasis during Colonoscopy: Randomized Controlled Trial

Background: Many studies have reported minor complications and disturbance of the gut microbiota after colonoscopy. Compared with air, carbon dioxide (CO₂) insufflation could decrease minor complications, but its impact on gut microbiota remains unknown. Methods: Thirty-eight healthy subjects were assessed and twenty were randomized to receive either CO₂ or air insufflation during colonoscopy. Neither the participants nor the staff involved in the follow-up knew which gas was used. Minor complications were assessed using symptom scores. Fecal samples were collected at eight time-points for microbiome analysis by full-length 16S rRNA gene amplicon analysis. Results: Baseline characteristics were similar in both groups. The recovery of minor complications after colonoscopy was faster in the CO₂ group (the day of the colonoscopy) than in the air group (the day after the colonoscopy). There was no significant reduction in alpha diversity (species richness) of the first stool after colonoscopy in the CO₂ group (115.0 ± 32.81 vs. 97.4 ± 42.31, p = 0.28) compared with the air group (123.8 ± 37.25 vs. 84.8 ± 31.67, p = 0.04). However, there were no differences in beta diversity between the groups. Linear discriminant analysis effect size (LEfSe) analysis indicated that anaerobic probiotics such as Bacteroides caccae, Bacteroides finegoldii and Bacteroides thetaiotaomicron were more abundant in the CO₂ group than in the air group within 14 days after colonoscopy. On the contrary, the content of Escherichiacoli, Ruminococcus torques and Ruminococcus guavus was higher in the air group. Conclusions: CO₂ is beneficial to gut microbiota homeostasis during colonoscopy in healthy subjects. The effects in patients with different diseases need to be further studied.

Key factors for improving adenoma detection rate

INTRODUCTION

Colonoscopy is a fundamental tool in colorectal cancer (CRC) prevention. Nevertheless, one-fourth of colorectal neoplasms are still missed during colonoscopy, potentially being the main reason for post-colonoscopy colorectal cancer (PCCRC). Adenoma detection rate (ADR) is currently known as the best quality indicator correlating with PCCRC incidence.

AREAS COVERED

We performed a literature review in order to summarize evidences investigating key factors affecting ADR: endoscopists education and training, patient management, endoscopic techniques, improved navigation (exposition defect), and enhanced lesions recognition (vision defect) were considered.

EXPERT OPINION

'Traditional' factors, such as split dose bowel preparation, adequate withdrawal time, and right colon second view, held a significant impact on ADR. Several devices and technologies have been developed to promote high-quality colonoscopy, however artificial intelligence may be considered the most promising tool for ADR improvement, provided that endoscopists education and recording are guaranteed.

Feasibility of salvage colonoscopy by water exchange for failed air-insufflated patients: a prospective, randomized, controlled trial

BACKGROUND

A complete colonoscopy is crucial for screening colorectal diseases and colorectal cancer. However, a failure rate of up to 43% still exists. Several studies have indicated that the water exchange method can enhance the cecal intubation rate while reducing discomfort of the patient. Water exchange colonoscopy (WEC) might be a salvage treatment for the patients who failed from air insufflation colonoscopy (AIC). We aimed to assess the feasibility of WEC as a salvage measure following the failure of conventional AIC.

METHODS

Patients willing to undergo unsedated colonoscopy at a tertiary-care referral center in China were randomly assigned 1:1 to WEC or AIC group for salvage after the initial AIC attempt failed. Patients were blinded to group assignment. The primary outcome was cecal intubation rate, the secondary outcomes included time to the cecum, maximum pain scores, and technical difficulty level.

RESULTS

Recruited 104 patients were randomized to the WEC (n = 52) or AIC (n = 52) group. WEC significantly increased the cecal intubation rate (92.3% vs 73.1%; p = .02). The maximum pain scores and technical difficulty level in the WEC group were significantly lower than the AIC group during salvage procedure (p < .001).

CONCLUSIONS

This randomized, controlled trial confirms that the WEC significantly enhanced cecal intubation rate in difficult colonoscopy in unsedated patients after the failure of standard AIC. The increased cecal intubation rate, lower pain scores and technical difficulty level suggest WEC is a good alternative for incomplete unsedated colonoscopy. Clinical trial registration number: ChiCTR2100051483.

Current endoscopic closure techniques for the management of gastrointestinal perforations

Acute gastrointestinal perforations occur either from spontaneous or iatrogenic causes. However, particular attention should be made in acute iatrogenic perforations as timely diagnosis and endoscopic closure prevent morbidity and mortality. With the increasing use of diagnostic endoscopy and advances in therapeutic endoscopy worldwide, the endoscopist must be able to recognize and manage perforations. Depending on the size and location of the defect, a variety of endoscopic clips, stents, and suturing devices are available. This review aims to prepare and guide the endoscopist to use the right tools and techniques for optimal patient outcomes.

Colonoscopy-related colonic ischemia

Colonoscopy is a risk factor for colon ischemia. The colon is susceptible to ischemia due to its minor blood flow compared to other abdominal organs; the etiology of colon ischemia after colonoscopy is multifactorial. The causative mechanisms include splanchnic circulation impairment, bowel preparation, drugs used for sedation, bowel wall ischemia due to insufflation/barotrauma, and introduction of the endoscope. Gastroenterologists must be aware of this condition and its risk factors for risk minimization, early diagnosis, and proper treatment.

Safety and Effectiveness of Endoscopic Band Ligation for Colonic Diverticular Bleeding in Elderly Patients

INTRODUCTION

Colonic diverticulosis increases with age, leading to a higher risk of colonic diverticular bleeding (CDB) in the elderly. As life expectancy continues to increase, the need for endoscopic hemostasis for CDB in the elderly can also be expected to increase. However, there have been no reports to date on the feasibility of endoscopic hemostasis for elderly CDB patients. Several recent studies have addressed the effectiveness of endoscopic band ligation (EBL) for CDB. In this study, we evaluate the safety and effectiveness of EBL in elderly CDB patients compared to younger CDB patients.

METHODS

We retrospectively analyzed the medical records of consecutive patients treated with EBL for the first time at a tertiary referral center between March 2011 and November 2017. Patients were grouped according to age into those at least 75 years old (the Elderly) and those <75 years old (the Nonelderly). Patient characteristics, technical success, and complications were compared between the two groups.

RESULTS

EBL was performed in 153 patients during the study period (49 Elderly patients and 104 Nonelderly patients). Elderly patients were less likely to be male (p < 0.001) and had lower hemoglobin levels on admission (p < 0.001). Bleeding on the right side of the splenic flexure was observed more frequently in the Nonelderly (p = 0.002). Charlson Comorbidity Index (CCI) and use of antithrombotic agents were significantly higher in the Elderly (p < 0.001 and p < 0.001, respectively). Active bleeding tended to be observed more frequently in the Elderly (p = 0.054), while the difference was not significant. There were no significant differences in the shock index, procedure time, or units of packed red blood cells transfused between the 2 groups. No significant differences in the technical success rate (97.1 vs. 98%, p = 0.76), early rebleeding rate (10.2 vs. 14.4%, p = 0.47), or other complications (2 vs. 1%, p = 0.58) were observed. Perforation and abscess formation were not observed in either group. Female gender, left-sidedness, higher CCI, and lower hemoglobin level were all significantly more frequently observed in the Elderly on multiple logistic regression analysis.

DISCUSSION/CONCLUSION

EBL may be similarly safe and effective for the treatment of CDB in the elderly as in the nonelderly.

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.

Perception and Practices of Colonoscopy Procedure: A Nationwide Survey of Indian Gastroenterologists

Introduction There is a lack of data and consensus about the practices and policies regarding performing colonoscopy in India. We surveyed gastroenterologists to assess their practices and policies of performing colonoscopy.

Methodology A questionnaire was presented to gastroenterologists all over India regarding their preference of bowel preparation and method of sedation, completeness of cecal and ileal intubation rates, preferences for inflation, use of carbon dioxide and nitrous oxide, and complications faced.

Results Of the 350 surveys, 307 had completely responded (88%). Only 18% of the centers were conducting more than 100 colonoscopies a month and 46% denied following a colon cancer screening policy. Two bottles of liquid polyethylene glycol were the most preferred preparation. A total of 21% did not prefer any sedation at all. Nitrous oxide was used by only 5.6% of doctors. Ileal intubation rate was >96% in 34% of centers and cecal intubation rate >96% in 58% of centers. Air was used for inflation by 58%, while 39% used CO2. A total of 40% of the respondents believe CO2 inflation would improve cecal intubation rate, while 9.4% believed otherwise. While one third found CO2 inflation unnecessary and 14% not cost-effective, three fourths were still interested in setting up a CO2 facility. Reasons for not using nitrous oxide were practical/administrative difficulty (46.6%), side effects (20%), and cost (16%). Still more than half surveyed would consider using Entonox in future. Perforation was the most noted complication faced by respondents.

Conclusions This survey of real-world clinical practices will help to formulate practice guideline regarding colonoscopy in India.

Ischemic Colitis after Colonoscopy with Bisacodyl Bowel Preparation: A Report of Two Cases

Background

Colonoscopy is widely used for the diagnosis and management of colorectal disease and requires adequate bowel preparation. Ischemic colitis is a form of intestinal ischemia that presents with abdominal pain, diarrhea, and hematochezia. Risk factors include advanced age, cardiovascular disease, and diabetes. Both colonoscopy and bisacodyl bowel preparation have been described as rare causes of ischemic colitis with less than 35 cases collectively in the literature. Our review found that of these cases, there exists significant heterogeneity within individual patient characteristics. The majority of the cases are managed conservatively without complications or sequela. Due to the risk of ischemic colitis, the FDA has withdrawn bisacodyl bowel preparations from use in the USA. Bisacodyl bowel preparations are still used in Canada.

Cases

Here, we present two cases of ischemic colitis in previously healthy women aged 57 and 69 who underwent screening colonoscopy using bisacodyl bowel preparation. Both were treated conservatively without complications.

Conclusion

Thus far, there has been one documented case of ischemic colitis following colonoscopy with bisacodyl bowel preparation; here, we present two additional cases with one case occurring without the presence of known risk factors for ischemic colitis. Our literature review finds that there is limited evidence surrounding bisacodyl as a causative agent of ischemic colitis. Cases often contain confounding variables such as the presence of known risk factors for ischemic colitis. Our report aims to highlight the need for a more comprehensive analysis evaluating the safety of bowel preparations as well as increasing the clinical awareness surrounding the rare risk of colonoscopy-induced ischemic colitis.

Effect of carbon dioxide versus room air insufflation on post-colonoscopic pain: A prospective, randomized, controlled study

BACKGROUND/AIMS

Room air (RA) and carbon dioxide (CO2) are widely used to insufflate the colon to examine the mucosa in colonoscopy. Pain, discomfort, and bloating can be seen during and after colonoscopy secondary to bowel distention. This study aimed to investigate the effect of CO2 on post-procedure pain sensation (PPPS) in comparison with RA.

MATERIALS AND METHODS

Patients were randomly assigned to the RA and CO2 insufflation groups in a 1:1 ratio. The visual analog scale (VAS) was used to measure the pain before and after the colonoscopy. VAS score of 0 was accepted as the absence of pain and above 0 was accepted as the presence of pain. The primary outcome was to investigate the effect of CO2 insufflation on PPPS. Secondary outcomes were to investigate the other contributing factors affecting PPPS and the effect of CO2 on PPPS in patients with inflammatory bowel disease (IBD).

RESULTS

A total of 204 patients were enrolled in the study. No significant difference in PPPS was seen between the 2 groups at any point in time after the colonoscopy. Furthermore, there was no significant difference in pain sensation between the CO2 and RA groups in patients with IBD. When we investigated the other contributing factors to pain sensation, body-mass index (BMI) was found to be significant at 30 minutes and BMI and colonoscopy time were found to be significant at 6 hours afterwards.

CONCLUSION

We found no favorable effect of CO2 insufflation on PPPS in colonoscopy, including in patients with IBD.

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.

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.

Clinical importance of cold polypectomy during the insertion phase in the left side of the colon and rectum: a multicenter randomized controlled trial (PRESECT study)

BACKGROUND AND AIMS

Colorectal polyps are often detected during the insertion phase of colonoscopy but are commonly removed during the withdrawal phase. We aimed to investigate the clinical advantages of instant removal of colorectal polyps during the insertion phase to determine the appropriate strategy for polyps detected on insertion.

METHODS

This prospective, multicenter, randomized trial targeted patients with at least 1 left-sided polyp <10 mm in size detected unintentionally on endoscope insertion from April 2018 to March 2019. Patients were allocated to the following 2 groups: study group, consisting of patients who had polyp removal instantly on insertion, and control group, comprising patients who had the endoscope inserted to the cecum first and polyps removed subsequently on withdrawal. Carbon dioxide gas insufflation and cold polypectomy were applied to minimize the influences of polypectomy on endoscope insertion. Twenty advanced endoscopists from 7 community-based institutions participated in this trial.

RESULTS

Of 1451 patients enrolled, 220 patients were eligible for full assessment. Mean total procedure time was significantly shorter in the study group (18.9 vs 22.3 minutes, P < .001). Mean pure cecal intubation time and number of polyps per patient were similar between the 2 groups. In the control group, among 107 polyps found during insertion, 48 (45.8%) required reinspection and 7 (6.5%) were completely missed, with an average reinspection time of approximately 3 minutes.

CONCLUSIONS

Polypectomy during the insertion phase in the colon and rectum significantly shortens the total procedure time and eliminates all missed polyps without experiencing any disadvantages.

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.

Updates on the Facilities, Procedures, and Performance of the Accredited Endoscopy Unit

Endoscopic quality indicators can be classified into three categories, namely facilities and equipment, endoscopic procedures, and outcome measures. In 2019, the Korean Society of Gastrointestinal Endoscopy updated the accreditation of qualified endoscopy unit assessment items for these quality indicators to establish competence and define areas of continuous quality improvement.

Here, we presented the updated program guidelines on the facilities, procedures, and performance of the accredited endoscopy unit. Many of these items have not yet been validated. However, the updated program will help in establishing competence and defining areas of continuous quality improvement in Korean endoscopic practice.

Bowel obstruction: a narrative review for all physicians

Small and large bowel obstructions are responsible for approximately 15% of hospital admissions for acute abdominal pain in the USA and ~ 20% of cases needing acute surgical care. Starting from the analysis of a common clinical problem, we want to guide primary care physicians in the initial management of a patient presenting with acute abdominal pain associated with intestinal obstruction.

Pediatric Endoscopy and High-risk Patients: A Clinical Report From the NASPGHAN Endoscopy Committee

Pediatric gastrointestinal endoscopy has been established as safe and effective for diagnosis and management of many pediatric gastrointestinal diseases. Nevertheless, certain patient and procedure factors should be recognized that increase the risk of intra- and/or postprocedural adverse events (AEs). AEs associated with endoscopic procedures can broadly be categorized as involving sedation-related physiological changes, bleeding, perforation, and infection. Factors which may increase patient risk for such AEs include but are not limited to, cardiopulmonary diseases, anatomical airway or craniofacial abnormalities, compromised intestinal luminal wall integrity, coagulopathies, and compromised immune systems. Examples of high-risk patients include patients with congenital heart disease, craniofacial abnormalities, connective tissues diseases, inflammatory bowel disease, and children undergoing treatment for cancer. This clinical report is intended to help guide clinicians stratify patient risks and employ clinical practices that may minimize AEs during and after endoscopy. These include use of CO2 insufflation, endoscopic techniques for maneuvers such as biopsies, and endoscope loop-reduction to mitigate the risk of such complications such as bleeding and intestinal perforation. Endoscopic infection risk and guidance regarding periprocedural antibiotics are also discussed.

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).

Gastroscopy Should Come Before Colonoscopy Using CO2 Insufflation in Same Day Bidirectional Endoscopies: A Randomized Controlled Trial

Background and Aims

Same day bidirectional endoscopies (esophagogastroduodenoscopies [EGD]s and colonoscopies) are routinely performed. However, the best sequence of procedures is unknown, as is whether the use of carbon dioxide (CO₂) affects the preferred sequence of procedures. This study aims to determine the preferred sequence of procedures and choice of insufflation gas (air or CO₂) in patients undergoing same day bidirectional endoscopies.

Methods

Two hundred adults with a clinical indication for same day bidirectional endoscopies were randomized equally into four groups: A1 (EGD first, CO₂ as insufflator); A2 (EGD first, air as insufflator); B1 (colonoscopy first, CO₂ as insufflator); and B2 (colonoscopy first, air as insufflator). All procedures were performed with conscious sedation (Midazolam/Fentanyl). The primary outcome was patients’ overall comfort/satisfaction with the procedures and sedation received, as assessed by questionnaires and validated scoring scales (Nurse-Assessed Patient Comfort Score [NAPCOMS], La Crosse [WI]) collected during the procedures, before discharge, and on day 7 postprocedure.

Results

Two hundred patients were randomized, with data available for 186. Mean Midazolam dose between groups was significantly less in the EGD first groups (P=0.01). During the procedures, no differences were found in patients’ comfort as per the nurse reported NAPCOMS scores (P=0.19) or the Lacrosse (WI) endoscopy scores (P=0.05). On postprocedure days 0 and 7, no differences were found in the patients’ reported Lacrosse (WI) scores, nausea, sore throat, dizziness, satisfaction with sedation or overall level of procedural satisfaction (P>0.05 for each). However, bloating and discomfort were significantly lower in the CO₂ arms (P<0.001).

Conclusions

This randomized controlled trial using validated patient comfort scoring assessments for same day bidirectional endoscopies demonstrated that the sequence of procedures affects the sedation used but does not affect overall patient comfort or satisfaction. Lesser sedation is needed in the EGD first group, and less postprocedural abdominal pain/discomfort and bloating is seen with CO₂ insufflation.

Quality measures improving endoscopic screening of colorectal cancer: a review of the literature

INTRODUCTION

Colorectal cancer (CRC) is a major health-care problem all over the world and CRC screening is effective in reducing mortality and increasing the 5-year survival. Colonoscopy has a central role in CRC screening. It can be performed as a primary test, as a recall policy after a positive result of another screening test, and for surveillance. Since effectiveness of endoscopic screening depends on adequate detection and removal of colonic polyps, consistent quality measures, which are useful in enhancing the diagnostic yield of examination, are essential. Areas covered: The aim of this review is to analyze current evidence from literature supporting quality measures able to refine endoscopic screening of colorectal cancer. Expert commentary: Quality measures namely a) time slot allotted to colonoscopy, b) assessment of indication, c) bowel preparation, d) Cecal intubation, e) withdrawal time, f) adenoma detection rate, g) proper management of lesions (polypectomy technique, polyps retrieval rate and tattooing of resection sites), and h) adequate follow-up intervals play a key role in identifying malignant and at-risk lesions and improving the outcome of screening. Adherence to these quality measures is critical to maximize the effectiveness of CRC screening, as well as, a proper technique of colonoscopy and a quality report of the procedure. Among all recommended measures, adenoma detection rate is the most important and must be kept above the recommended quality threshold by all physicians practicing in the setting of screening.

Randomized controlled trial of probiotic use for post-colonoscopy symptoms

BACKGROUND

Symptoms of bloating, discomfort and altered bowel function persist post-colonoscopy in up to 20% of patients. A previous randomized controlled trial of probiotics for post-colonoscopy symptoms has demonstrated a reduction in duration of pain with the use of probiotics. This was performed with air insufflation and the question was asked whether the effect would persist with the use of carbon dioxide to insufflate the colon.

METHODS

Eligible patients were recruited and randomized to receive either probiotic or placebo capsules post colonoscopy. A questionnaire was completed documenting the presence of pre-procedural and post-procedural symptoms for the following 2 weeks. The results were entered into a database and processed by an independent statistician. The primary outcome was mean pain score and incidence of bloating over the first 7 days and at 14 days post procedure. The secondary outcome was the time to return of normal bowel function.

RESULTS

Two hundred and forty participants were recruited and randomized (120 probiotic and 120 placebo). Data were available for 75 patients in the probiotic and 75 in the placebo group. There was no significant difference between groups in post-procedural discomfort, bloating nor time to return of normal bowel function. Subgroup analysis of the patients with preexisting symptoms showed a reduction in incidence of bloating with the use of probiotics.

CONCLUSION

There may be a role for the use of probiotics in the subgroup of patients with preexisting symptoms; however, routine use of probiotics to ameliorate post-procedural symptoms of carbon dioxide insufflation colonoscopy cannot be advocated.

Modifiable factors associated with patient-reported pain during and after screening colonoscopy

OBJECTIVE

Pain associated with colonoscopy is a major burden for patients. We investigated modifiable factors associated with patient-reported pain during and after colonoscopy.

DESIGN

This cross-sectional analysis included database records from 23 centres participating in a population-based colonoscopy screening programme in Poland. Colonoscopies were performed under three sedation modalities: none, benzodiazepine-opioid sedation or propofol sedation. We used Gastronet (a validated tool) to assess patients' pain during and after colonoscopy; pain was scored on a four-point scale (no, little, moderate or severe pain), with moderate to severe defined as painful. We used multivariate logistic regression models to estimate ORs for painful colonoscopy and calculated risk-adjusted ratios of painful colonoscopies per endoscopist and compared it to the mean rate.

RESULTS

Of 35 216 screening colonoscopies in 2014 and 2015 included in our study, 22 725 (64.5%) patients returned valid Gastronet questionnaires. The proportion of examinations described as causing pain during (after) the procedure was 22.5% (14.2%) for unsedated, 19.9% (13.5%) for benzodiazepine-opioid sedation and 2.5% (7.5%) for propofol sedation. Propofol sedation, higher case volume of endoscopists, newest endoscope generation and adequate bowel preparation were significantly associated with lower odds of painful colonoscopy. Pain scores after colonoscopy showed similar associations. Adjusted pain rates during and after colonoscopy varied 11 and over 23-fold, respectively, between endoscopists.

CONCLUSION

We identified several independent, modifiable factors associated with pain during and after colonoscopy, of which individual endoscopist was the most important. Dedicated training should be considered to decrease variability among endoscopists.

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.

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.

Difficult colonoscopy: air, carbon dioxide, or water insufflation?

Background/Aims

This study aimed to compare tolerance to air, carbon dioxide, or water insufflation in patients with anticipated difficult colonoscopy (young, thin, obese individuals, and patients with prior abdominal surgery or irradiation).

Methods

Patients with body mass index (BMI) less than 18 kg/m² or more than 30 kg/m², or who had undergone previous abdominal or pelvic surgeries were randomized to air, carbon dioxide, or water insufflation during colonoscopy. The primary endpoint was cecal intubation with mild pain (less than 5 on visual analogue scale [VAS]), without use of sedation.

Results

The primary end point was achieved in 32.7%, 43.8%, and 84.9% of cases with air, carbon dioxide and water insufflation (P<0.001). The mean pain scores were 5.17, 4.72, and 3.93 on the VAS for air, carbon dioxide, and water insufflation (P<0.001). The cecal intubation rate or procedure time did not differ significantly between the 3 groups.

Conclusions

Water insufflation was superior to air or carbon dioxide for pain tolerance. This was seen in the subgroups with BMI <18 kg/m² and the post-surgical group, but not in the group with BMI >30 kg/m².

COLONOSCOPY: RANDOMIZED COMPARATIVE STUDY OF INSUFFLATION WITH CARBON DIOXIDE VERSUS AIR

Background:

In Brazil, an increasing number of people are submitted to colonoscopy, either for screening or for therapeutic purposes.

Aim:

To evaluate whether there are advantages of using carbon dioxide (CO₂) over air for insufflation.

Methods:

Two hundred and ten of 219 patients were considered eligible for this study and were randomized into two groups according to the gas insufflation used: Air Group (n=104) and CO₂ Group (n=97). The study employed a double-blind design.

Results:

The Air and CO₂ Groups were similar in respect to bowel preparation evaluated using the Boston scale, age, gender, previous surgery, maneuvers necessary for the advancement of the device, and presence of polyps, tumors or signs of diverticulitis. However, “waking up with pain” and “pain at discharge” were more prevalent in the Air Group, albeit not statistically significant, with post-exam bloating seen only in the Air Group. The responses to a questionnaire, applied to analyze the late post-exam period, showed more comfort with the use of CO₂.

Conclusions:

The use of CO₂ is better than air as it avoids post-examination bloating, thereby providing greater comfort to patients.

The Difficult Colorectal Polyp

Difficult colorectal polyps represent lesions that pose a challenge to traditional endoscopic snare polypectomy. These polyps have historically been managed by surgical resection. Currently, several less invasive options are available to avoid colectomy. Repeat colonoscopy and snare polypectomy by an expert endoscopist, endoscopic mucosal resection, endoscopic submucosal dissection, and combined endoscopic and laparoscopic surgery have been developed to remove difficult polyps without the need for formal surgical resection. Patients with rectal polyps have the advantage of additional transanal minimally invasive techniques to enhance their resectability. Today, most colorectal polyps can be managed without the need for formal surgical resection.

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.).

Ultrathin versus pediatric instruments for colonoscopy in older female patients: A randomized trial

BACKGROUND AND AIM

Small-caliber endoscopes such as gastroscopes or pediatric colonoscopes are occasionally required to negotiate fixed or angulated colons. However, the use of a new ultrathin instrument (diameter 7.0 mm) narrower than other conventional colonoscopes has not been evaluated. The aim of the present study was to compare the use compare the use of an ultrathin colonoscope (UTC) with a pediatric colonoscope (PDC) for colonoscopy in older female patients.

METHODS

A prospective, randomized, controlled trial was conducted in a single academic endoscopy unit. A total of 77 female patients aged ≥70 years undergoing unsedated colonoscopy were randomized to colonoscopy with a UTC (n = 39) or PDC (n = 38). Primary outcome measurement was the degree of pain using a numerical rating scale, and secondary outcomes were cecal intubation rate, ileal intubation rate, time to cecum and adenoma detection rate.

RESULTS

There was a significant difference in reported pain using the numerical rating scale (median, UTC 1 vs PDC 4, P < 0.0001). Cecal intubation rates were 97.4% in UTC and 92.1% in PDC (P = 0.36), and ileal intubation rates were 82.0% and 89.4% (P = 0.76), respectively. However, median times to cecum were significantly longer using UTC compared with PDC (15.2 min vs 11.1 min, P = 0.022). Adenoma detection rates were 30.7% in UTC and 26.3% in PDC (P = 0.80).

CONCLUSIONS

Colonoscopy using UTC was almost equivalent to that of PDC in older female patients, with significantly less pain compared with PDC. UTC may be an alternative to PDC for the difficult colon.

Impact of carbon dioxide insufflation and water exchange on postcolonoscopy outcomes in patients receiving on-demand sedation: a randomized controlled trial

BACKGROUND AND AIMS

Water exchange (WE) is the least painful insertion method during colonoscopy. Its impact on postcolonoscopy discomfort has not been well-described. Carbon dioxide (CO₂) insufflation consistently reduced postcolonoscopy discomfort. We compared postcolonoscopy outcomes of various combinations of insertion and withdrawal techniques (insertion-withdrawal modality): WE-CO₂, WE-air insufflation (WE-AI), and CO₂-CO₂.

METHODS

A total of 240 patients undergoing on-demand sedation diagnostic colonoscopy were randomized to WE-CO₂ (n = 79), WE-AI (n = 80), CO₂-CO₂ (n = 81), with postprocedural data collected up to 24 hours. The primary outcome was postcolonoscopy bloating. Other postcolonoscopy outcomes included pain scores, flatus and incontinence episodes, toilet use, interference with normal activities, patient satisfaction, and patient willingness to repeat the procedure.

RESULTS

Demographic and procedural data were comparable. Compared with WE-AI, WE-CO₂ and CO₂-CO₂ resulted in significantly less bloating (all P < .0005) and lower pain scores (P values ranged from .008 to < .0005) up to 3 hours and fewer flatus episodes up to 6 hours (P values ranged from .003 to < .0005). WE-CO₂ resulted in less interference with same-day activities compared with WE-AI (P = .043). The differences in postprocedural outcomes were significant, but the magnitude was small. Patient satisfaction and willingness to repeat the procedure were high and comparable among groups. WE was the least painful insertion technique (P < .0005).

CONCLUSIONS

The combination WE-CO₂ appears to be the optimal choice to decrease pain during the examination and to reduce bloating and other undesired procedural outcomes afterward. If a CO₂ insufflator is already available, it seems advisable to adopt the combination WE-CO₂. In the absence of a CO₂ insufflator, the cost effectiveness of the addition of withdrawal CO₂ to WE in diagnostic and nondiagnostic settings needs to be critically assessed. (Clinical trial registration number: NCT02409979.).

Endoscopic management of mucosal lesions in the gastrointestinal tract

With the increasing role of endoscopy in patient evaluation, more mucosal lesions, including gastric, duodenal and colonic polyps, are encountered during routine examinations. It is imperative for gastroenterologists to become familiar with the endoscopic management of these various gastrointestinal lesions. In this article, various resection techniques will be discussed, including hot/cold forceps polypectomy, hot/cold snare polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection. The article will also discuss the evidence regarding the efficacy and safety of these techniques and the future direction of endoscopic management of mucosal lesions in the gastrointestinal tract.

Expert opinions and scientific evidence for colonoscopy key performance indicators

Colonoscopy is a widely performed procedure with procedural volumes increasing annually throughout the world. Many procedures are now performed as part of colorectal cancer screening programmes. Colonoscopy should be of high quality and measures of this quality should be evidence based. New UK key performance indicators and quality assurance standards have been developed by a working group with consensus agreement on each standard reached. This paper reviews the scientific basis for each of the quality measures published in the UK standards.

Effectiveness of Intraluminal Air Decompression on Postcolonoscopic Pain According to Reinsertion Site

Background

Colonoscopy is a very effective and essential examination to diagnose colorectal cancer; however, many patients experience discomfort due to post-examination abdominal pain, which reduces colonoscopy compliance. This study was conducted to determine methods for reducing post-colonoscopic abdominal pain.

Methods

We conducted a randomized controlled study of 405 male and female adults who visited Hana General Hospital in Cheongju. We surveyed general characteristics, history of colonoscopy, and other related factors, then categorized examinees into 5 groups (0–5) according to the site of scope reinsertion. Pain was measured using a numeric rating scale (NRS).

Results

The mean age of examinees in this study was 47.8 years, and 210 participants had prior experience of colonoscopy. No significant difference was observed between variables, with the exception of reinsertion duration (P=0.005). Pain scores were different between performing physicians (P=0.006), and were higher when the subjective level of procedure difficulty was low (P=0.026) in univariate analysis. Pain scores decreased as the reinsertion site became closer to the proximal colon (P<0.001), but there was no significant difference between groups 3 and 4. The results of multiple logistic regression analysis, including univariate analysis, showed that group 1 had 0.48 times, group 2 had 0.38 times, group 3 had 0.09 times, and group 4 had 0.03 times odds ratio (moderate-to-severe pain, NRS ≥4) than control group 0.

Conclusion

Air decompression by scope reinsertion is an effective way to reduce abdominal pain after colonoscopy. Removing air when the reinserted scope approaches the hepatic flexure seems to be the most effective method to reduce post-colonoscopic pain.

Randomized, double-blind trial of CO2 versus air insufflation in children undergoing colonoscopy

BACKGROUND AND AIMS

Studies in adults have shown that postprocedural abdominal pain is reduced with the use of carbon dioxide (CO(2)) instead of air for insufflation during colonoscopy. The aim of our study was to compare postprocedural abdominal pain and girth in children undergoing colonoscopy using CO(2) or air for insufflation.

METHODS

This was a prospective, randomized, double-blind study that included 76 consecutive pediatric patients undergoing colonoscopy for various indications. Patients were randomly assigned to either CO(2) or air insufflation. At 2, 4, and 24 hours after the examination, the patients' pain was assessed by using the 11-point numerical rating scale. The waist circumference was measured 10 minutes and 2 and 4 hours after colonoscopy.

RESULTS

A significantly higher proportion of patients had no pain after colonoscopy in the CO(2) group compared with the air group (82 vs 37% at 2 hours and 95% vs. 63% at 4 hours, P < .001). Mean abdominal pain scores 2 and 4 hours after the procedure were statistically significantly lower in the CO(2) group compared with the control air group (0.5 vs 2.6 at 2 hours and 0.1 vs 1.2 at 4 hours, P < .001). There was no difference in waist circumference between the 2 groups at all time intervals.

CONCLUSION

The results of this randomized trial show clear benefits of CO(2) insufflation for colonoscopy in reducing postprocedural discomfort. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT02407639.).

Autonomic nervous responses in colorectal polypectomy: Randomized controlled trial comparing air and carbon dioxide insufflation

BACKGROUND AND AIM

Carbon dioxide (CO2) insufflation devices are commonly used for endoscopic examination and treatment. In this prospective randomized controlled trial (RCT), we compared patient acceptance, cardiovascular tolerance,and autonomic nervous responses between patients receiving air insufflation and CO2 insufflation.

METHODS

We initially enrolled 170 patients and, of these, 158 patients in total were analyzed (air group, 83; CO2 group, 75). Autonomic nervous responses were evaluated by analysis of heart rate variability (HRV). Primary end point was superiority in the effects of CO2 insufflation on the autonomic nervous system by HRV analysis.

RESULTS

Visual analog scale disclosed significantly less abdominal pain and abdominal fullness with CO2. Percentage heart rate change rate at 1 h and 4 h after the procedure was also significantly lower in the CO2 group than in the air group (1 h after: P < 0.01, 4 h after: P < 0.05). Comparison based on age showed that % heart rate change was significantly lower in the younger CO2 patients (just after colonoscopy and 1 h after: P < 0.01, 4 h after: P < 0.05), but this difference was not apparent in an older group of patients.

CONCLUSIONS

This is the first RCT showing that colorectal polypectomy using CO2 insufflation significantly decreases abdominal pain and abdominal fullness common in such patients with lowered stress to the autonomous nervous system. The effects using CO2 insufflation on the sympathetic nervous system also seemed to be more prominent among younger patients.

Diagnostic and therapeutic applications of water-immersion colonoscopy

Colonoscopy techniques combining or replacing air insufflation with water infusion are becoming increasingly popular. They were originally designed to reduce colonic spasms, facilitate cecal intubation, and lower patient discomfort and the need for sedation. These maneuvers straighten the rectosigmoid colon and enable the colonoscope to be inserted deeply without causing looping of the colon. Water-immersion colonoscopy minimizes colonic distension and improves visibility by introducing a small amount of water. In addition, since pain during colonoscopy indicates risk of bowel perforation and sedation masks this important warning, this method has the potential to be the favored insertion technique because it promotes patient safety without sedation. Recently, this water-immersion method has not only been used for colonoscope insertion, but has also been applied to therapy for sigmoid volvulus, removal of lesions, lower gastrointestinal bleeding, and therapeutic diagnosis of abnormal bowel morphology and irritable bowel syndrome. Although a larger sample size and prospective head-to-head-designed studies will be needed, this review focuses on the usefulness of water-immersion colonoscopy for diagnostic and therapeutic applications.