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

British Society of Gastroenterology guidelines on sedation in gastrointestinal endoscopy

Over 2.5 million gastrointestinal endoscopic procedures are carried out in the United Kingdom (UK) every year. Procedures are carried out with local anaesthetic r with sedation. Sedation is commonly used for gastrointestinal endoscopy, but the type and amount of sedation administered is influenced by the complexity and nature of the procedure and patient factors. The elective and emergency nature of endoscopy procedures and local resources also have a significant impact on the delivery of sedation. In the UK, the vast majority of sedated procedures are carried out using benzodiazepines, with or without opiates, whereas deeper sedation using propofol or general anaesthetic requires the involvement of an anaesthetic team. Patients undergoing gastrointestinal endoscopy need to have good understanding of the options for sedation, including the option for no sedation and alternatives, balancing the intended aims of the procedure and reducing the risk of complications. These guidelines were commissioned by the British Society of Gastroenterology (BSG) Endoscopy Committee with input from major stakeholders, to provide a detailed update, incorporating recent advances in sedation for gastrointestinal endoscopy.This guideline covers aspects from pre-assessment of the elective 'well' patient to patients with significant comorbidity requiring emergency procedures. Types of sedation are discussed, procedure and room requirements and the recovery period, providing guidance to enhance safety and minimise complications. These guidelines are intended to inform practising clinicians and all staff involved in the delivery of gastrointestinal endoscopy with an expectation that this guideline will be revised in 5-years' time.

Water-assisted colonoscopy: an international modified Delphi review on definitions and practice recommendations

BACKGROUND AND AIMS

Since 2008, a plethora of research studies has compared the efficacy of water-assisted (aided) colonoscopy (WAC) and underwater resection (UWR) of colorectal lesions with standard colonoscopy. We reviewed and graded the research evidence with potential clinical application. We conducted a modified Delphi consensus among experienced colonoscopists on definitions and practice of water immersion (WI), water exchange (WE), and UWR.

METHODS

Major databases were searched to obtain research reports that could potentially shape clinical practice related to WAC and UWR. Pertinent references were graded (Grading of Recommendations, Assessment, Development and Evaluation). Extracted data supporting evidence-based statements were tabulated and provided to respondents. We received responses from 55 (85% surveyed) experienced colonoscopists (37 experts and 18 nonexperts in WAC) from 16 countries in 3 rounds. Voting was conducted anonymously in the second and third round, with ≥80% agreement defined as consensus. We aimed to obtain consensus in all statements.

RESULTS

In the first and the second modified Delphi rounds, 20 proposed statements were decreased to 14 and then 11 statements. After the third round, the combined responses from all respondents depicted the consensus in 11 statements (S): definitions of WI (S1) and WE (S2), procedural features (S3-S5), impact on bowel cleanliness (S6), adenoma detection (S7), pain score (S8), and UWR (S9-S11).

CONCLUSIONS

The most important consensus statements are that WI and WE are not the same in implementation and outcomes. Because studies that could potentially shape clinical practice of WAC and UWR were chosen for review, this modified Delphi consensus supports recommendations for the use of WAC in clinical practice.

Cecal intubation time between the use of one-channel and two-channel water exchange colonoscopy: A randomized controlled trial

BACKGROUND AND AIM

Water exchange (WE) colonoscopy is the least painful insertion technique with high adenoma detection rate but requires a longer intubation time. In the published literature, some investigators used the instrument channel for both infusing and suctioning of water (one channel), while others use colonoscopes with an integrated water-jet channel specifically designed for infusing water (two channel). The aim of this study was to compare cecal intubation time between one-channel and two-channel WE.

METHODS

A total 120 patients undergoing colonoscopy from May 2017 to April 2019 at a regional hospital in southern Taiwan were randomized to either a two-channel group (n = 60) or a one-channel group (n = 60). The primary outcome was cecal intubation time.

RESULTS

The mean cecal intubation time was significantly shorter in the two-channel group compared with the one-channel group (14.0 ± 4.0 vs 17.4 ± 6.7 min, P < 0.001). The two-channel group required less water infused during insertion (564.8 ± 232.4 vs 1213.3 ± 467.5 mL, P < 0.001) but achieved a significantly higher Boston Bowel Preparation Scale score (8.4 ± 0.8 vs 7.5 ± 1.1, P < 0.001) than did the one-channel group. The adenoma detection rate was comparable in the two groups (50.0% vs 48.3%, P = 0.855).

CONCLUSIONS

In comparison with the one-channel WE, two-channel WE showed a shorter cecal intubation time, required less amount of water during insertion, and provided a better salvage cleansing effect. (NCT03279705).

Covid-19 pandemic impact on colonoscopy service and suggestions for managing recovery

Background and aim  As the post-peak phase of the epidemic is approaching, there is an urgent need of an action plan to help resume endoscopy activity. To manage the Covid-19 pandemic-imposed backlog of postponed colonoscopy examinations, an efficient approach is needed. The practice of on-demand sedation with benzodiazepines and/or opiates will allow most patients to complete a water-aided examination with minimal or no sedation. Other methods reported to minimize patient discomfort during colonoscopy can be used, in addition to water-aided techniques. Unsedated or minimally sedated patients who do not require recovery or require a shorter one allow rapid turnaround. The practice obviates the need for assistance with deep sedation from anesthesiologists, who may be in short supply. Trainee education in water-aided colonoscopy has been demonstrated to confer benefits. This review provides some insights into the impact of Covid-19 on endoscopy services, challenges ahead, and possible solutions to help recovery of colonoscopy work and training.

Postcolonoscopy Appendicitis: A Review of 57 Cases

The purpose of this study is to review the cases of postcolonoscopy appendicitis (PCA) reported in the literature. A comprehensive search using PubMed, EMBASE, Scopus, and Google Scholar identified 57 cases. The median age at presentations of PCA was 55 years. PCAs typically occurred during the first 24 hours after colonoscopy, and the majority developed after diagnostic colonoscopy. Clinical presentations were similar to those with common acute appendicitis, though with a high perforation rate. Most patients were correctly diagnosed using ultrasound or computed tomography scan. Treatment included open appendicectomy, laparoscopic appendicectomy or cecotomy, radiologic drainage of the abscess, nonoperative treatment with antibiotics. In addition to barotrauma, fecalith impaction into the appendiceal lumen, direct trauma to the appendiceal orifice, and underlying ulcerative colitis, a pre-existing subclinical disease of the appendix seems to play an important role in the pathogenesis. For PCA, timely diagnosis and management are crucial to attain a satisfactory outcome.

Underwater Endoscopic Mucosal Resection

Although an established standard, conventional endoscopic mucosal resection (EMR) has disseminated despite an absence of studies demonstrating the value of submucosal injection. Several consequences of poorly executed submucosal injection may increase the difficulty and risk of EMR. Underwater EMR (UEMR), an alternative resection method for colonic neoplasms, avoids the need for submucosal injections. In comparison with reported outcomes of EMR, UEMR achieves similar rates of complete resection with comparable safety, with lower rates of recurrence and fewer repeat procedures. UEMR also compares favorably with endoscopic submucosal dissection in terms of procedure time and rates of complete resection, recurrence, and complications.

A pilot study of a novel variable-stiffness stylet for efficient colonoscope insertion with <i>ex-vivo</i> colon model

Objectives: The variable-stiffness colonoscope is reportedly useful for making colonoscope insertion easier. However, this function is not associated with all colonoscopes. We developed a variable-stiffness stylet that can be inserted into the endoscope instrumentation channel to change the rigidity of the endoscope. Methods: We developed a stylet with adjustable stiffness and investigated its utility in colonoscope insertion using an ex-vivo model. Four endoscopists performed 24 colonoscope insertions, alternating between using the stylet (Stylet method) and the conventional method. We assessed insertion rate, rate of applying abdominal compression, and insertion time between the two groups. Results: In all procedures, the endoscope was inserted up to the cecum. There were significantly fewer external abdominal compressions with the Stylet method (1/12, 8.3%) compared to the conventional method (6/12, 50%). The insertion time was shorter with the Stylet method (140.9 ± 53.7 s) compared to the conventional method (181.3 ± 64.9 s). Conclusions: Using the variable-stiffness stylet, currently under development, resulted in significantly fewer external abdominal compressions and tended to have shorter insertion time.

Diagnostic application of water exchange colonoscopy: A meta-analysis of randomized controlled trials

Background

Few well-designed studies have investigated water exchange colonoscopy (WE). We performed a meta-analysis to comprehensively evaluate the clinical utility of WE based on high-quality randomized controlled trials (RCTs) and to compare the impacts of WE, water immersion colonoscopy (WI), and gas-insufflation colonoscopy.

Methods

We searched the Cochrane Library, MEDLINE, Embase, PubMed, Elsevier, CNKI, VIP, and Wan Fang Data for RCTs on WE. We analyzed the results using fixed- or random-effect models according to the presence of heterogeneity. Publication bias was assessed by funnel plots.

Results

Thirteen studies were eligible for this meta-analysis. The colonoscopic techniques included WE as the study group, and WI and air- or CO₂-insufflation colonoscopy as control groups. WE was significantly superior to the control procedures in terms of adenoma detection rate, proportion of painless unsedated colonoscopy procedures, and cecal intubation rate according to odds ratios. WE was also significantly better in terms of maximal pain score and patient satisfaction score according to mean difference.

Conclusions

WE can remarkably improve the adenoma detection rate, proportion of painless unsedated colonoscopy procedures, patient satisfaction, and cecal intubation rate, as well as reducing the maximal pain score in patients undergoing colonoscopy.

Impact of water exchange colonoscopy on endoscopy room efficiency: a systematic review and meta-analysis

BACKGROUND AND AIMS

Separate randomized controlled trials (RCTs) showed water exchange (WE) colonoscopy outperformed other techniques in minimizing insertion pain and optimizing adenoma detection rate. Longer insertion time required for removal of infused water, residual air, and feces might have hampered its wider adoption. We evaluate the impact of WE compared with air or carbon dioxide insufflation (GAS) on room turnaround efficiency measured by cecal intubation, withdrawal, and total procedure times.

METHODS

With a systematic search in PubMed, Embase, and Cochrane Library, we identified RCTs (published before March 18, 2018) that compared WE with GAS. We focused on parameters of turnaround efficiency and patient-centered outcomes.

RESULTS

We analyzed 8371 subjects from 17 studies. Demographics and indications were comparable. Mean cecal intubation time (± standard deviation) was WE 12.5 ± 6.1 minutes versus GAS 11.1 ± 7.0 minutes, with a mean difference of 1.4 ± 3.4 minutes. Six studies showed significant differences in insertion time, with mean cecal intubation times of 11.6 ± 5.1 minutes for WE versus 7.7 ± 5.2 minutes for GAS, with a mean difference of 3.9 ± 1.1 minutes. Mean withdrawal time was similar. Mean total procedure time was WE 26.0 ± 9.7 versus GAS 24.2 ± 9.6, with a mean difference of 1.8 ± 6.2 minutes. All mean procedure times were significantly different. Patient-centered outcomes revealed that patients examined with WE had significantly lower real-time insertion pain score, less need for sedation, and higher willingness to repeat the procedure.

CONCLUSIONS

Based on parameters of procedural time, the impact of WE colonoscopy on endoscopy room turnaround yields an increase in total procedure time of about 2 minutes and is associated with significant improvement in specific patient-centered outcomes.

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.

Do we really need an anesthesiologist for routine colonoscopy in American Society of Anesthesiologist 1 and 2 patients?

PURPOSE OF REVIEW

In an era where healthcare costs are being heavily scrutinized, every expenditure is reviewed for medical necessity. Multiple national gastroenterology societies have issued statements regarding whether an anesthesiologist is necessary for routine colonoscopies in American Society of Anesthesiologist (ASA) 1 and 2 patients.

RECENT FINDINGS

A large percentage of patients are undergoing screening colonoscopy without any sedation at all, which would not require an independent practitioner to administer medications. Advances in technique and technology are making colonoscopies less stimulating. Advantages to administering sedation, including propofol, have been seen even when not administered under the direction of an anesthesiologist and complications seem to be rare. The additional cost of having monitored anesthesia care appears to be a driving factor in whether a patient receives it or not.

SUMMARY

A large multiinstitutional randomized control trial would be necessary to rule out potential confounders and to determine whether there is a safety benefit or detriment to having anesthesiologist-directed care in the setting of routine colonoscopies in ASA 1 and 2 patients. Further discussion would be necessary regarding what the monetary value of that effect is if a small difference were to be detected.

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.

Underwater endoscopic colorectal polyp resection: Feasibility in everyday clinical practice

BACKGROUND

Endoscopic mucosal resection is well-established for resecting flat or sessile benign colon polyps. The novel underwater endoscopic mucosal resection eschews submucosal injection prior to endoscopic mucosal resection. Reports about underwater endoscopic mucosal resection were limited to small series of single and/or tertiary-care referral centers, with single or supervised operators.

OBJECTIVE

The purpose of this study was to determine feasibility and efficacy of underwater resection of polyps of any morphology (underwater polypectomy, here includes underwater endoscopic mucosal resection) in routine clinical practice.

METHODS

This study involved a comparison of colonoscopy records of two community hospitals (January 2015-December 2016) for underwater polypectomy (n = 195) and gas insufflation polypectomy (n = 186).

RESULTS

Comparable demographics, procedural data, overall distribution, morphology and size of resected lesions, number of en bloc and R0 resections (any polyp morphology and size); exception: overall, underwater polypectomy pedunculated polyps were significantly larger than those in the gas insufflation polypectomy group, p = 0.030. Underwater polypectomy (median, min) resection time was significantly shorter than gas insufflation polypectomy: sessile and flat polyps 6-9 mm, 0.8 vs 2.7 (p = 0.040); 10-19 mm, 2.0 vs 3.3 (p = 0.025), respectively; pedunculated polyps 6-19 mm, 0.8 vs 3.3 (p < 0.001). Underwater polypectomy resection of pedunculated polyps 6-19 mm showed significantly less immediate bleeding: 11.1% vs 1.5%, respectively (p = 0.031).

CONCLUSIONS

Underwater polypectomy can be efficaciously used in routine clinical practice for the complete resection of colon polyps, with several advantages over gas insufflation polypectomy.

Cecal intubation time between cap-assisted water exchange and water exchange colonoscopy: a randomized-controlled trial

BACKGROUND AND AIM

The water exchange (WE) method can decrease the discomfort of the patients undergoing colonoscopy. It also provides salvage cleansing and improves adenoma detection, but a longer intubation time is required. Cap-assisted colonoscopy leads to a significant reduction in cecal intubation time compared with traditional colonoscopy with air insufflation. The aim of this study was to investigate whether combined cap-assisted colonoscopy and water exchange (CWE) could decrease the cecal intubation time compared with WE.

PATIENTS AND METHODS

A total of 120 patients undergoing fully sedated colonoscopy at a regional hospital in southern Taiwan were randomized to colonoscopy with either CWE (n=59) or WE (n=61). The primary endpoint was cecal intubation time.

RESULTS

The mean cecal intubation time was significantly shorter in CWE (12.0 min) compared with WE (14.8 min) (P=0.004). The volume of infused water during insertion was lower in CWE (840 ml) compared with WE (1044 ml) (P=0.003). The adenoma detection rate was 50.8 and 47.5% for CWE and WE, respectively (P=0.472). The Boston Bowel Preparation Scale scores were comparable in the two groups. Results from the multiple linear regression analysis indicated that WE with a cap, a higher degree of endoscopist's experience, a higher Boston Bowel Preparation Scale score, and a lower volume of water infused during insertion, without abdominal compression, without change of position, and without chronic laxative use, were significantly associated with a shorter cecal intubation time.

CONCLUSION

In comparison with WE, CWE could shorten the cecal intubation time and required lower volume of water infusion during insertion without compromising the cleansing effect of WE.