Residual Gastric Volume After Bowel Preparation With Polyethylene Glycol for Elective Colonoscopy: A Prospective Observational Study

Is monitoring of gastric residual volume for critically ill patients with enteral nutrition necessary? A meta-analysis and systematic review

BACKGROUND

There are many controversies over the necessity of monitoring gastric residual volume in the nursing care of enteral nutrition. We aimed to conduct an updated meta-analysis to evaluate the effects of monitoring or not monitoring gastric residual volume on patients' outcomes and complications.

METHODS

We searched the Cochrane Library database to 15 April 2021 for randomized controlled trials (RCTs) on the effects of gastric residual volume and no gastric residual volume monitoring. Review Manager software was used for data analysis.

RESULTS

A total of seven RCTs involving 1240 enteral nutrition patients were included. Gastric residual volume monitoring was associated with reduced incidence of vomiting (OR2.33, 95% CI:1.68-3.24), whereas no gastric residual volume monitoring was associated with reduced incidence of unnecessary interruptions of enteral nutrition (OR0.38,95% CI:0.26-0.55). There were no significant differences on the incidence of abdominal distention (OR1.87, 95% CI:0.82-4.28), diarrhoea (OR1.03,95% CI:0.74-1.43), VAP (OR0.83, 95%CI:0.37-1.89), duration of mechanical ventilation (MD -0.06,95% CI:-1.22-1.10), length of ICU stay (MD -1.33, 95% CI:-3.58-0.91) and mortality (OR0.90,95% CI:0.61-1.34).

CONCLUSIONS

Not monitoring gastric residual volume is associated with reduced unnecessary interruptions of enteral nutrition related to inadequate feeding and increased risk of vomiting.

Relationship between perioperative semaglutide use and residual gastric content: A retrospective analysis of patients undergoing elective upper endoscopy

STUDY OBJECTIVE

Semaglutide is a long-acting glucagon-like peptide-1 receptor agonist used for management of type 2 diabetes and/or obesity. To test the hypothesis that perioperative semaglutide use is associated with delayed gastric emptying and increased residual gastric content (RGC) despite adequate preoperative fasting, we compared the RGC of patients who had and had not taken semaglutide prior to elective esophagogastroduodenoscopy. The primary outcome was the presence of increased RGC.

DESIGN

Single-center retrospective electronic chart review.

SETTING

Tertiary hospital.

PATIENTS

Patients undergoing esophagogastroduodenoscopy under deep sedation/general anesthesia between July/2021-March/2022.

INTERVENTIONS

Patients were divided into two (SG = semaglutide, NSG = non-semaglutide) groups, according to whether they had received semaglutide within 30 days prior to the esophagogastroduodenoscopy.

MEASUREMENTS

Increased RGC was defined as any amount of solid content, or > 0.8 mL/Kg (measured from the aspiration/suction canister) of fluid content.

MAIN RESULTS

Of the 886 esophagogastroduodenoscopies performed, 404 (33 in the SG and 371 in the NSG) were included in the final analysis. Increased RGC was observed in 27 (6.7%) patients, being 8 (24.2%) in the SG and 19 (5.1%) in the NSG (p < 0.001). Semaglutide use [5.15 (95%CI 1.92-12.92)] and the presence of preoperative digestive symptoms (nausea/vomiting, dyspepsia, abdominal distension) [3.56 (95%CI 2.2-5.78)] were associated with increased RGC in the propensity weighted analysis. Conversely, a protective [0.25 (95%CI 0.16-0.39)] effect against increased RGC was observed in patients undergoing esophagogastroduodenoscopy combined with colonoscopy. In the SG, the mean time of preoperative semaglutide interruption in patients with and without increased RGC was 10.5 ± 5.5 and 10.2 ± 5.6 days, respectively (p = 0.54). There was no relationship between semaglutide use and the amount/volume of RGC found on esophagogastroduodenoscopy (p = 0.99). Only one case (in the SG) of pulmonary aspiration was reported.

CONCLUSIONS

Semaglutide was associated with increased RGC in patients undergoing elective esophagogastroduodenoscopy. Digestive symptoms prior to esophagogastroduodenoscopy were also predictive of increased RGC.

Graphical education and appropriate time before elective colonoscopy make better bowel preparation

Background

Inadequate bowel preparation leads to lower polyp detection rates, longer procedure times and lower cecal intubation rates. However, there is no consensus about high-quality bowel preparation, so our study evaluated graphical education and appropriate time before elective colonoscopy.

Patients and Methods

We performed a secondary analysis of a national colorectal cancer screening programme of 738 patients. The patients were divided into a group given a graphical information manual (n = 242) or a word-only one (n = 496). They were also divided into groups according to the interval between bowel preparation and colonoscopy: 6-8 h (Group 1, n = 106), 9-12 h (Group 2, n = 228) and 13-17 h (Group 3, n = 402). All patients were scored according to the Boston Bowel Preparation Scale (BBPS) during the examination.

Results

The bowel preparation of the graphical group was significantly better than the text group (P < 0.001). After adjustment, the bowel preparation score of Group 1 and Group 2 were both significantly higher than that of Group 3 (P = 0.012 and P = 0.032). Maximum BBPS was 6.31 when the interval time was 6.52 h (95% confidence interval: 5.95-6.66), and when the interval was <10 h, the BBPS was ≥6.

Conclusion

High-quality bowel preparation was linked to graphical education and appropriate time before colonoscopy. We suggest that the interval between taking the first laxative and colonoscopy should be <10 h, preferably 6.5 h. Prospective multicentre research is needed to give more evidence of high-quality bowel preparation methods.

Multi-center study of residual gastric volume and bowel preparation after the usage of 1L and 2L polyethylene glycol in Korea

BACKGROUND

In colonoscopy, good bowel preparation is an important factor in determining the quality of colonoscopy. However, an increase in residual gastric volume (RGV) can lead to a higher risk of aspiration pneumonia. Therefore, the purpose of this study was to investigate the factors related to an increase in RGV with the usage of 1L polyethylene glycol (PEG).

METHODS

We prospectively analyzed 268 patients who underwent both gastroscopy and colonoscopy at 2 hospitals from May to October 2021. Bowel preparation was performed using 1L in 127 patients (47.4%) and 2L PEG in 141 patients (52.6%). We investigated the time taken for bowel preparation solutions, the last water intake, total water intake, and RGV, and conducted a survey on taking compliance and satisfaction.

RESULTS

The level of RGV was significantly increased in the 1L PEG group when compared to the 2L PEG group (1L, 52.26 ± 65.33 vs 2L, 23.55 ± 22.99; P < .001). There was no difference between the 2 groups in the degree of bowel preparation, but there were more bubbles formed in the 1L group (1L, 1.91 ± 2.74 vs 2L, 1.10 ± 2.02; P = .007). In the case of RGV ≥ 50 mL, in multivariate analysis, the risk was higher in water intake within 5 hours and the patients who think the dose is too high (all P < .05).

CONCLUSION

Therefore, since RGV is higher in 1L PEG than in 2L PEG, it is necessary to be careful not to take water for at least 5 hours before the test.

Evaluation of pH and residual gastric volume after colon preparation with mannitol: prospective randomized study comparing procedure performed after 3 hours versus 6 hours

OBJECTIVES

Our goal was to compare the hydrogen potential (pH) and residual gastric volume (RGV) of patients undergoing colonoscopy after 3 and 6 hours of colon preparation with mannitol.

METHODS

We described a prospective randomized trial with a 50:50 allocation rate of two distinct times of colonoscopy after colon preparation with 10% mannitol. We included outpatients aged over 18 years, with no history of gastric surgeries and an American Society of Anesthesiologists (ASA)-rated anesthetic risk below III. Colonoscopy was performed after upper digestive endoscopy at two different times: 3 versus 6-hour after mannitol ingestion. During upper gastrointestinal endoscopy, we measured RGV and evaluated pH with a digital pH meter. Clinical trials.gov: 71123317.9.3001.0065.

RESULTS

We randomized a total of 100 participants to the 3 and 6-hour groups, with the patients in the 6-hour group being younger and presenting a higher body mass index (BMI). The intervention did not result in any statistically significant differences between the two groups, neither for the RGV (p=0.98) or the pH (p=0.732). However, the subgroup of patients with diabetes mellitus showed statistically significant higher RGV values in the 3-hour group.

CONCLUSION

There was no difference between RGV and pH values at 3 versus 6-hour after bowel preparation with mannitol, except for RGV in diabetic patients at 3 hours. As prolonged fasting protocols may result in adverse events such as dehydration and electrolyte imbalance, we can infer that colonic preparation with mannitol in shorter fasting periods, such as 3 hours, can be adopted safely and routinely.

Anesthesia Assistance in Outpatient Colonoscopy and Risk of Aspiration Pneumonia, Bowel Perforation, and Splenic Injury

BACKGROUND & AIMS

The increase in use of anesthesia assistance (AA) to achieve deep sedation with propofol during colonoscopy has significantly increased colonoscopy costs without evidence for increased quality and with possible harm. We investigated the effects of AA on colonoscopy complications, specifically bowel perforation, aspiration pneumonia, and splenic injury.

METHODS

In a population-based cohort study using administrative databases, we studied adults in Ontario, Canada undergoing outpatient colonoscopy from 2005 through 2012. Patient, endoscopist, institution, and procedure factors were derived. The primary outcome was bowel perforation, defined using a validated algorithm. Secondary outcomes were splenic injury and aspiration pneumonia. Using a matched propensity score approach, we matched persons who had colonoscopy with AA (1:1) with those who did not. We used logistic regression models under a generalized estimating equations approach to explore the relationship between AA and outcomes.

RESULTS

Data from 3,059,045 outpatient colonoscopies were analyzed; 862,817 of these included AA. After propensity matching, a cohort of 793,073 patients who had AA and 793,073 without AA was retained for analysis (51% female; 78% were age 50 years or older). Use of AA did not significantly increase risk of perforation (odds ratio [OR], 0.99; 95% confidence interval [CI], 0.84-1.16) or splenic injury (OR, 1.09; 95% CI, 0.62-1.90]. Use of AA was associated with an increased risk of aspiration pneumonia (OR, 1.63; 95% CI, 1.11-2.37).

CONCLUSIONS

In a population-based cohort study, AA for outpatient colonoscopy was associated with a significantly increased risk of aspiration pneumonia, but not bowel perforation or splenic injury. Endoscopists should warn patients, especially those with respiratory compromise, of this risk.

Split-dose bowel preparation with polyethylene glycol for colonoscopy performed under propofol sedation. Is there an optimal timing?

OBJECTIVE

Aspiration risk, especially with propofol sedation, remains a concern after split-dose bowel preparation of up to 1 L polyethylene glycol for the procedure. We aimed to identify the ideal timing of bowel preparation to achieve optimal colon cleansing with no increased risk of aspiration.

METHODS

A total of 892 consecutive patients undergoing simultaneous esophagogastroduodenoscopy (EGD) and colonoscopy were prospectively recruited. Residual gastric volume (RGV) and pH of gastric contents were measured at EGD, and patients' characteristics, runway time (duration between completion of the final liter of bowel preparation and colonoscopy commencement), and cleansing quality were recorded.

RESULTS

A shorter runway time resulted in better colon cleansing (r = -0.124, P < 0.001). No correlation between runway time and RGV or pH was found (r = -0.017, P = 0.62 and r = -0.030, P = 0.47, respectively). RGV and pH did not differ significantly with runway time of 4 or 5 h. RGV with runway time ≤3 h was 35.9 ± 11.8 mL and 17.4 ± 0.6 mL after runway time >3 h (P < 0.001). No aspiration pneumonia occurred. The only factors independently related to higher RGV were younger age and male sex.

CONCLUSIONS

The consumption of bowel preparation agent within 3-4 h before propofol sedation resulted in a similar RGV and pH as those achieved by more prolonged fasting, with no increased risk of aspiration even in patients perceived to be at high risk.