Carbon dioxide insufflation does not reduce pain scores during colonoscope insertion in unsedated patients: a randomized, controlled trial

VOLUMETRIC CAPNOGRAPHY FOR RESPIRATORY MONITORING OF PATIENTS DURING ROUTINE COLONOSCOPY WITH ROOM-AIR AND CARBON DIOXIDE INSUFFLATION

BACKGROUND

Capnography and carbon dioxide (CO2) insufflation during gastrointestinal endoscopy under sedation are associated with safety and comfort improvements, respectively. Capnography can provide early detection of apnea and hypoxemia, whereas CO2 insufflation causes lower periprocedural discomfort. This is the first study to report the application of volumetric capnography in colonoscopy.

OBJECTIVE

This study aimed to evaluate the use of volumetric capnography with room air (RA) and CO2 insufflation during routine colonoscopy.

METHODS

In this prospective cohort study, 101 patients who underwent routine colonoscopy under sedation with volumetric capnography monitoring were included. Insufflation with RA was used to distend the intestinal lumen in group 1 (n=51), while group 2 (n=50) used CO2 insufflation. The primary endpoints were episodes of hypoxia, alveolar hypoventilation, and end-tidal CO2 (EtCO2). The secondary endpoints were tidal volume per minute, consumption of sedation medications, and post-procedure pain using the Gloucester modified pain scale.

RESULTS

The number of episodes of hypoxia (SpO2<90%) was similar between the groups: four episodes in Group 1 and two episodes in Group 2. The duration of hypoxia was significantly longer in group 2 (P=0.02). Hypoalveolar ventilation (EtCO2) occurred more frequently in Group 2 than in Group 1 (27 vs 18 episodes, P=0.05). Regarding EtCO2, Group 2 showed higher values in cecal evaluation (28.94±4.68 mmHg vs 26.65±6.12 mmHg, P=0.04). Regarding tidal volume per minute, Group 2 had significantly lower values at the cecal interval compared to Group 1 (2027.53±2818.89 vs 970.88±1840.25 L/min, P=0.009). No episodes of hypercapnia (EtCO2 > 60 mmHg) occurred during the study. There was no difference in the consumption of sedation medications between the groups. Immediately after colonoscopy, Group 2 reported significantly less pain than Group 1 (P=0.05).

CONCLUSION

In our study, volumetric capnography during colonoscopy was feasible and effective for monitoring ventilatory parameters and detecting respiratory complications. CO2 insufflation was safe and associated with less pain immediately after colonoscopy.

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.

Randomized Controlled Trial of Polyethylene Glycol versus Oral Sodium Phosphate for Bowel Preparation in Unsedated Colonoscopy

Aim

To identify the most effective laxative for bowel preparation in unsedated colonoscopy.

Methods

Between April 2019 and April 2020, a total of 586 outpatients scheduled for unsedated colonoscopy at the First Hospital of Jilin University (Changchun, China) were randomized into one of two groups, namely, the polyethylene glycol (PEG) group or the oral sodium phosphate solution (OSP) group. The cleaning efficiency and other relevant clinical parameters were compared between the two groups.

Results

Each group consisted of 293 patients. There were no significant differences in gender, body mass index, and history of abdominal surgery between the two groups. There were more cases of laxative intolerance in the PEG group than in the OSP group (7.5% vs. 0.7%, P < 0.05). After tube insertion, we found that the cleaning efficiency of OSP was better than that of PEG (P < 0.05). After cleaning, there was no significant difference in bowel cleanliness between the two groups (P > 0.05). The colonoscopic insertion time of the PEG group was significantly shorter than that of the OSP group (10.0 vs. 12.0 min, P = 0.002), and colonoscopic insertion was more difficult in the OSP group than in the PEG group (P = 0.036). The VAS score of the PEG group patients was significantly lower than that of OSP group patients (4.0 ± 1.3 vs. 5.2 ± 1.7, P ≤ 0.001). There were no significant differences in the cecal intubation rate and the detection rate of polyps and ulcers/erosion between the two groups.

Conclusion

The cleaning efficiency and tolerability of OSP were preferable to those of PEG, but there was no significant difference in bowel cleanliness after washing the colon and suctioning the fluid. Compared with patients of the OSP group, those of the PEG group required a shorter colonoscopic insertion time and reported a more comfortable experience. Therefore, for cases that are tolerant of PEG, PEG is a better choice for unsedated colonoscopy.

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.

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.

Feasibility of sedation on demand in Taiwan using water exchange and air insufflation: A randomized controlled trial

BACKGROUND AND AIM

Completion of colonoscopy without sedation eliminates sedation cost and complications. Reported in the United States and Europe, on-demand sedation is not routine practice in Taiwan. Water exchange (WE), characterized by infusion and nearly complete removal of infused water during insertion, reduces insertion pain compared to air insufflation (AI) during colonoscopy. We evaluated the feasibility of on-demand sedation in Taiwan. In a randomized controlled trial of WE vs AI colonoscopy, we also aimed to determine if WE augmented the implementation by reducing insertion pain and decreasing sedation requirement.

METHODS

This prospective patient-blinded study randomized patients to AI or WE (75 patients/group) to aid insertion. The primary outcome was the proportion of patients completing without sedation.

RESULTS

In the AI and WE groups, 76.0% and 93.3% (P = 0.006) completed without need for sedation, respectively. The WE group had lower insertion pain score (mean [SD]) (4.0 [2.9] vs 2.1 [2.6], P < 0.001), lower doses of propofol (25.7 [52.7] mg vs 9.1 [35.6] mg, P = 0.012), and less time in the recovery room (3.4 [7.4] vs 1.5 [5.5], P = 0.027) than the AI group. Patient satisfaction scores and willingness to repeat if needed in the future were similar.

CONCLUSION

On-demand sedation was feasible in Taiwan. The completion rate without sedation was high in patients (76.0% with standard AI) open to the option (no prior intent to receive the standard of full or minimal sedation). WE augmented the implementation by reducing insertion pain and decreasing sedation requirement without adversely affecting patient satisfaction or willingness to repeat.

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.

Carbon Dioxide Versus Air Insufflation for Elective Colonoscopy: A Meta-Analysis and Systematic Review of Randomized Controlled Trials

AIMS AND OBJECTIVE

The aim of this study was to conduct a meta-analysis and systematic review of randomized controlled trials (RCTs) comparing 2 methods of colonic insufflation for elective colonoscopy, that is, carbon dioxide (CO2) or air, and to evaluate their efficiency, safety, and side effects.

MATERIALS AND METHODS

Prospective RCTs comparing CO2 versus air insufflation for colonic distension during colonoscopy were selected by searching PubMed, Medline, Embase, Science Citation Index, Current Contents, and the Cochrane Central Register of Controlled Trials published between January 1980 and October 2014. The outcome variables analyzed included procedural and immediate postprocedural pain (during, end, or within 15 min after procedure), early postprocedural pain (between 30 and 120 min), intermediate postprocedural pain (360 min) and late postprocedural pain (720 to 1140 min), cecal/ileal intubation rate, cecal/ileal intubation time, and total colonoscopy examination time. These outcomes were unanimously decided to be important as they influence the practical approach toward patient management within and outside of hospital. Random effects model was used to calculate the effect size of both binary and continuous data. Heterogeneity among the outcome variables of these trials was determined by the Cochran Q statistic and I2 index. The meta-analysis was prepared in accordance with PRISMA guidelines.

RESULTS

Twenty-four RCTs totaling 3996 patients (CO2=2017, Air=1979) were analyzed. Statistically significant differences for the pooled effect size were observed for procedural and immediate postprocedural pain [weighted mean difference (WMD)=0.49; 95% confidence interval (CI), 0.32, 0.73; P=0.0005], early postprocedural pain between 30 and 120 minutes (WMD=0.25; 95% CI, 0.12, 0.49; P<0.0001), intermediate postprocedural pain, that is, 360 minutes after completion (WMD=0.35; 95% CI, 0.23, 0.52; P<0.0001), and late postprocedural pain between 720 and 1440 minutes (WMD=0.53; 95% CI, 0.34, 0.84; P=0.0061). Comparable effects were noted for cecal/ileal intubation rate (WMD=0.86; 95% CI, 0.61, 1.22; P=0.3975), cecal/ileal intubation time (WMD=-0.64; 95% CI, -1.38, 0.09; P=0.0860), and total examination time (WMD=-0.20; 95% CI, -0.96, 0.57; P=0.6133).

CONCLUSIONS

On the basis of our meta-analysis and systematic review, we conclude that CO2 insufflation significantly reduces abdominal pain during and following the procedure lasting up to 24 hours. There is no difference in the cecal/ileal intubation rate and time and total examination time between the 2 methods. CO2 retention with CO2 insufflation during and after the colonoscopy shows inconsequential variation compared with air insufflation and has no adverse effect on patients. CO2 instead of air should be routinely utilized for colonoscopy.

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.).

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.

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.

Carbon dioxide insufflation or warm-water infusion for unsedated colonoscopy: A randomized controlled trial in patients with chronic constipation in China

AIMS

The effect of carbon dioxide (CO2) insufflation and warm-water infusion during colonoscopy on patients with chronic constipation remains unknown. We evaluated CO 2 insufflation and warm-water irrigation versus air insufflation in unsedated patients with chronic constipation in China.

PATIENTS AND METHODS

This randomized, single-center, controlled trial enrolled 287 consecutive patients, from January 2014 to January 2015, who underwent colonoscopy for chronic constipation. Patients were randomized to CO2 insufflation, warm-water irrigation and air insufflation colonoscopy insertion phase groups. Pain scores were assessed by the visual analog scale (VAS). The primary outcome was real-time maximum insertion pain, recorded by an unblinded nurse assistant. At discharge, the recalled maximum insertion pain was recorded. Meanwhile, patients were requested to select the VAS at 0, 10, 30, and 60 min after the procedure. In addition, cecal intubation and withdrawal time, total procedure time, and adjunct measures were recorded.

RESULTS

A total of 287 patients were randomized. The correlation between real-time and recalled maximum insertion pain ((Pearson coefficient r = 0.929; P < 0.0001) confirmed internal validation of the primary outcome. The mean real-time maximum pain scores during insertion 2.9 ± 2.1 for CO2, 2.7 ± 1.9 for water achieved a significantly lower pain score compared with air (5.7 ± 2.5) group (air vs CO2 P < 0.001; air vs water P < 0.001). However, no significant pain score differences were found between the patients in the CO2 and water groups (CO2 vs water, P = 0.0535). P values in painless colonoscopy and only discomfort colonoscopy (pain 1-2) were, respectively, 6 (6.4%) and 8 (8.5%) for air; 17 (17.7%) and 29 (30.2%) for CO2; 16 (16.5%) and 31 (31.9%) for water. At 0, 10, 30, and 60 min postprocedure, pain scores showed in the CO2 and water groups had significantly reduced than in air group. Insertion time was significantly different between air (10.6 ± 2.5) and CO2 ( 7.2 ± 1.4) (air vs CO2 P < 0.001), air and water (6.9 ± 1.3) (air vs water P < 0.001). However, CO2 and was not significantly different in cecum-intubated time (CO2 vs water, P = 0.404). CO2 and water group in extubation time were significantly different, respectively, CO2 (7.9 ± 1.1) and water (8.0 ± 1.1) (CO2 vs water, P = 0.707). CO2 or water group required less implementation of adjunct measures and more willingness to repeat the procedure.

CONCLUSIONS

Compared with air, the CO2 or water-aided method reduced real-time maximum pain and cecum-intubated time for chronic constipated patients in unsedated colonoscopy. The CO2 insufflation or warm-water irrigation may be a simple and inexpensive way to reduce discomfort in unsedated patients with constipation. This study demonstrated an advantage of using CO2 insufflation and warm-water irrigation during colonoscopy in unsedated constipated patients in China.

Total Colonic Decompression After Colonoscopy Decreases Postcolonoscopy Abdominal Pain: A Randomized Double-Blind Controlled Trial

GOALS

The purpose of this study was to determine whether total colonic decompression after colonoscopy decreased postcolonoscopy abdominal pain.

BACKGROUND

Abdominal pain that occurs after a colonoscopy may cause significant discomfort in some patients, and residual bowel gas is thought to be a key contributor to this abdominal pain.

STUDY

Asymptomatic 300 patients who underwent colonoscopy under sedation were randomized to either the decompression group or the control group. Initial colonoscopic procedure was performed uniformly in both the groups. After the colonoscopy examination was completed, the colonoscope was reinserted into the cecum, and the intraluminal air was aspirated during withdrawal in the decompression group. Abdominal pain was assessed before discharge and 24 to 48 hours after colonoscopy using a 10-point visual analogue scale (VAS).

RESULTS

The 2 groups were similar with regard to clinical, demographic, and procedural factors. Among 288 patients, the incidence of abdominal pain (VAS≥1) after colonoscopy was 38 (26.6%) of 143 patients in the decompression group and 95 (65.5%) of 145 patients in the control group (VAS 0.68±1.35 vs. 2.14±2.15, P<0.001). There was an 86.1% reduction rate of abdominal pain by colonic decompression, based on multivariate analysis (odds ratio 0.139 [95% confidence interval, 0.077-0.250], P<0.001). Furthermore, independent factors for abdominal pain included female gender and total duration of procedure >800 seconds. There were no reinsertion-related complications in the decompression group.

CONCLUSION

Total colonic decompression after colonoscopy has a beneficial effect and can reduce postcolonoscopy abdominal pain without additional complications.

Portable inhaled methoxyflurane is feasible and safe for colonoscopy in subjects with morbid obesity and/or obstructive sleep apnea

BACKGROUND AND STUDY AIMS

Colonoscopy with inhaled methoxyflurane (Penthrox) is well tolerated in unselected subjects and is not associated with respiratory depression. The aim of this prospective study was to compare the feasibility, safety, and post-procedural outcomes of portable methoxyflurane used as an analgesic agent during colonoscopy with those of anesthesia-assisted deep sedation (AADS) in subjects with morbid obesity and/or obstructive sleep apnea (OSA).

PATIENTS AND METHODS

The outcomes of 140 patients with morbid obesity/OSA who underwent colonoscopy with either Penthrox inhalation (n = 85; 46 men, 39 women; mean age 57.2 ± 1.1 years) or AADS (n = 55; 27 men, 28 women; mean age, 54.9 ± 1.1 years) were prospectively assessed.

RESULTS

All Penthrox-assisted colonoscopies were successful, without any requirement for additional intravenous sedation. Compared with AADS, Penthrox was associated with a shorter total procedural time (24 ± 1 vs. 52 ± 1 minutes, P < 0.001), a lower incidence of hypotension (3 /85 vs. 23 /55, P < 0.001), and a lower incidence of respiratory desaturation (0 /85 vs. 14 /55, P < 0.001). The patients in the Penthrox group recovered more rapidly and were discharged much earlier than those in the AADS group (27 ± 2 vs. 97 ± 5 minutes, P < 0.0001). Of those who underwent colonoscopy with Penthrox, 90 % were willing to receive Penthrox again for colonoscopy. More importantly, of the patients who underwent colonoscopy with Penthrox and had had AADS for previous colonoscopy, 82 % (28 /34) preferred to receive Penthrox for future colonoscopies. Penthrox-assisted colonoscopy cost significantly less than colonoscopy with AADS ($ 332 vs. $ 725, P < 0.001), with a cost saving of approximately $ 400 for each additional complication avoided.

CONCLUSIONS

Compared with AADS, Penthrox is highly feasible and safe in patients with morbid obesity/OSA undergoing colonoscopy and is associated with fewer cardiorespiratory complications. Because of the advantages of this approach in regard to procedural time, recovery time, and cost benefit in comparison with AADS, further evaluation in a randomized trial is warranted.

What Influences the Quality of Prevention Colonoscopy?

Background

Colorectal cancer still has a high incidence and mortality. Although colonoscopy is considered as gold standard of colorectal cancer screening, there still exists an unsatisfactory level of adenomas missed in screening and surveillance colonoscopy. Furthermore, patients bear the burden of potentially unpleasant and painful examination and preparation procedures.

Method

A search of the literature using PubMed was carried out, supplemented by a review of the programs of the Digestive Disease Week (DDW) and the United European Gastroenterology Week (UEGW) 2011-2013.

Results

Several new approaches to colonoscopy were described: water, CO₂ and cap colonoscopy, and application of spasmolytics such as hyoscine butylbromide and glucagon. The use of these methods does not necessitate the purchase of new endoscopes. They are feasible and safe, facilitate achieving the aim of more comfort and less pain, and perhaps allow lower doses of sedatives to be used. However, a clear effect on procedure time is lacking. Furthermore, the published data do not consistently answer the question of whether these techniques have a positive impact on the most important goal, the better detection of carcinoma precursors.

Conclusion

More efforts to optimize bowel preparation have to be made to improve visualization of the mucosal surface. The most reliable criteria for the quality of screening and surveillance colonoscopy remain a minimum cecal intubation rate of >90%, a withdrawal time of at least 6 or better 9 min, and an adenoma detection rate of >20%. These results should be achieved with a complication rate lower than 1%, including polypectomy.

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

AIM

Conventional air insufflation (AI) may cause prolonged abdominal bloating, excessive abdominal pain and discomfort during colonoscopy. Carbon dioxide may be an acceptable alternative to avoid these complications. The object of this study was to evaluate systematically the effectiveness of carbon dioxide insufflation (CI) for colonoscopy compared with AI.

METHOD

Randomized controlled trials (RCTs) comparing the effectiveness of CI with that of AI during colonoscopy were retrieved from medical electronic databases and combined analysis was performed using the RevMan statistical package. The combined outcome of dichotomous and continuous variables was expressed as an odds ratio (OR) and standardized mean difference (SMD).

RESULTS

Twenty-one RCTs comprising 3607 patients were included in the study. There was statistically significant heterogeneity among included studies. CI showed a significant trend towards reduced procedural pain [SMD -1.34; 95% confidence interval (95% CI) -2.23 to -0.45; z = 2.96; P < 0.003] and also postprocedural pain at 1 h (SMD -1.11; 95% CI -1.83 to -0.38; z = 2.97; P < 0.003), 6 and 24 h (OR 0.44; 95% CI 0.23-0.85; z = 2.44; P < 0.01). CI was associated with faster caecal intubation (SMD -0.20; 95% CI -0.37 to -0.02; z = 2.23; P < 0.03) but the caecal intubation rate was similar (P = 0.59) in both colonic insufflation techniques .

CONCLUSION

CI seems to have clinical advantages over AI for colonoscopy with regard to pain during and after the procedure.

Is the type of insufflation a key issue in gastro-intestinal endoscopy?

Endoscopic procedures continue to play an emerging role in diagnosing and treating upper and lower gastrointestinal (GI) disorders. In particular, the introduction of colonoscopy in bowel cancer screening has underlined its promising role in decreasing the incidence of colorectal cancer and reducing tumour related mortality. To achieve these goals patients need to contemplate endoscopic examinations as painless and fearless procedures. The use of carbon dioxide (CO₂) as an alternative insufflation gas in comparison to air has been considered as an essential key to improving patients' acceptance in undergoing endoscopic procedures. CO₂ is absorbed quickly through the bowel mucosa causing less luminal distension and potentially less abdominal pain. However, its exact role has not been defined completely. In particular, the beneficial use of CO₂ in upper GI endoscopy and in sedated patients is still conflicting. In the present review, we aimed to assess the current evidence for using CO₂ in endoscopy and to evaluate its potential role in the future.

Patient-controlled analgesia with inhaled methoxyflurane versus conventional endoscopist-provided sedation for colonoscopy: a randomized multicenter trial

OBJECTIVE

Inhaled methoxyflurane (Penthrox, Medical Device International, Melbourne, Australia) has been used extensively in Australasia (Australia and New Zealand) to manage trauma-related pain. The aim is to evaluate the efficacy, safety, and outcome of Penthrox for colonoscopy.

DESIGN

Prospective randomized study.

SETTING

Three tertiary endoscopic centers.

PATIENTS

Two hundred fifty-one patients were randomized to receive either Penthrox (n = 125, 70 men, 51.4 ± 1.1 years old) or intravenous midazolam and fentanyl (M&F; n = 126, 72 men, 54.9 ± 1.1 years old) during colonoscopy.

MAIN OUTCOME MEASUREMENT

Discomfort (visual analogue scale [VAS] pain score), anxiety (State-Trait Anxiety Inventory Form Y [STAI-Y] anxiety score), colonoscopy performance, adverse events, and recovery time.

RESULTS

Precolonoscopy VAS pain and STAI-Y scores were comparable between the 2 groups. There were no differences between groups in (1) pain VAS or STAI Y-1 anxiety scores during or immediately after colonoscopy, (2) procedural success rate (Penthrox: 121/125 vs M&F: 124/126), (3) hypotension during colonoscopy (7/125 vs 8/126), (4) tachycardia (5/125 vs 3/126), (5) cecal arrival time (8 ± 1 vs 8 ± 1 minutes), or (6) polyp detection rate (30/125 vs 43/126). Additional intravenous sedation was required in 10 patients (8%) who received Penthrox. Patients receiving Penthrox alone had no desaturation (oxygen saturation [SaO(2)] < 90%) events (0/115 vs 5/126; P = .03), awoke quicker (3 ± 0 vs 19 ± 1 minutes; P < .001) and were ready for discharge earlier (37 ± 1 vs 66 ± 2 minutes; P < .001) than those receiving intravenous M&F.

LIMITATIONS

Inhaled Penthrox is not yet available in the United States and Europe.

CONCLUSIONS

Patient-controlled analgesia with inhaled Penthrox is feasible and as effective as conventional sedation for colonoscopy with shorter recovery time, is not associated with respiratory depression, and does not influence the procedural success and polyp detection.

Colon polypectomy: a review of routine and advanced techniques

The value of performing comprehensive screening colonoscopy with complete colon polypectomy is widely accepted. Colon cancer is a significant cause of worldwide mortality and prospective studies have proven that colonoscopic polypectomy reduces both the incidence and mortality related to this disease. Over the past few decades the array of instruments and techniques have greatly expanded to assist with the safe endoscopic removal of colon polyps. This article will review the published literature regarding efficacy and safety of standard polypectomy techniques such as snare polypectomy, electrocautery, and endoscopic mucosal resection along with newer techniques such as endoscopic submucosal dissection and combined laparoscopic techniques.

Magnetic endoscopic imaging during colonoscopy is associated with less pain and decreased need of analgesia and sedation--results from a randomized controlled trial

OBJECTIVE

Colonoscopy is the method of choice for examining patients with lower gastrointestinal symptoms. The procedure is, however, in many cases, associated with pain and impaired compliance. Magnetic endoscopic imaging (MEI) generates a three-dimensional image of the colonoscope on a computer screen which may enable the colonoscopist to avoid looping, and consequently improve patient satisfaction.

MATERIAL AND METHODS

In this randomized controlled trial, 200 outpatients referred to colonoscopy at Østfold Hospital Trust, Fredrikstad, Norway, were included. Patients were randomized to either the standard arm (using fluoroscopy on demand, n = 100), or the MEI arm (n = 100). End points were time to cecum, subjective pain experiences, and use of sedation or analgesics.

RESULTS

Out of a total of 200 patients, 54% were men. However, no significant differences between the groups according to gender were found. Fluoroscopy was applied in 23% of the cases in the standard group. Use of MEI was associated with decreased time to cecum (p < 0.05), decreased pain scores (Visual Analogue Scale, p < 0.05), decreased need of analgesia (p < 0.01), and decreased amount of administered midazolam and pethidin (p < 0.05 in both).

CONCLUSIONS

MEI during colonoscopy was associated with decreased pain and less on-demand requests for sedation and analgesia. In addition, the use of MEI reduced the cecal intubation time. Consequently the implementation of magnetic endoscopic imaging in the endoscopy suits may be beneficial, particularly in the clinically difficult cases.