Electrolyte disturbances after bowel preparation for colonoscopy: Systematic review and meta-analysis.

BACKGROUND AND STUDY AIMS: We conducted a systematic review and meta-analysis of population-based studies to explore pooled prevalence and magnitude of electrolyte changes after bowel preparation for colonoscopy based on the most recent guidelines. PATIENTS AND METHODS: PubMed and Cochrane were queried for population-based studies examining changes in electrolyte values after bowel preparation, published by July 1, 2021. We report prevalences of serum hypokalemia, hyponatremia, hyperphosphatemia, and hypocalcemia after bowel preparation and changes in mean electrolyte values after vs. before bowel preparation using sodium phosphate (NaP) and polyethylene glycol (PEG). RESULTS: Thirteen studies met the inclusion criteria; 2386 unique patients were included. Overall, hypokalemia was found in 17.2% (95% CI 6.7, 30.9) in the NaP group vs. 4.8% (95% CI 0.27, 13.02) in the PEG group. The magnitude of potassium decrease after NaP bowel preparation was significantly increased compared to PEG (mean difference -0.38; 95% CI -0.49 to -0.27, P < 0.001). No study reported on major complications. CONCLUSIONS: Hypokalemia was found in 17.2% of patients after bowel preparation with NaP and in 4.8% of patients with PEG, a finding that is clinically relevant with respect to choosing the type of bowel preparation. The magnitude of the potassium decrease after NaP was significantly higher compared to PEG. These data provide the evidence that supports the recommendation of the European Society of Gastrointestinal Endoscopy against routine use of NaP for bowel preparation.

Prevalence of hypokalemia before and after bowel preparation for colonoscopy in high-risk patients.

BACKGROUND AND AIMS: Bowel preparation for colonoscopy should not cause significant shifts in systemic electrolyte concentrations. We recently encountered 2 cases of severe postcolonoscopy hypokalemia with fatal consequences, prompting us to conduct a study to explore the magnitude of and risk factors for hypokalemia associated with bowel preparation. We paid specific attention to higher-risk subgroups, in particular, diuretic users, hospitalized patients, and patients estimated to be at high risk by the gastroenterologist. METHODS: From January 1 to December 31, 2014, we included all patients at risk for hypokalemia (diuretic users, hospitalized patients, and patients estimated at high risk by the gastroenterologist) who underwent colonoscopy at our institution. We measured serum potassium levels before low-volume polyethylene glycol bowel preparation for colonoscopy. In a subset of patients who had normal serum potassium levels before bowel cleansing, serum potassium levels after bowel cleansing also were measured. RESULTS: In total, 5515 colonoscopies were performed, including 1822 procedures in diuretic users or hospitalized patients. Of these, 77 (4.2%) patients had hypokalemia before bowel cleansing. A logistic regression model showed that hospitalized patients were more likely to have hypokalemia than non-hospitalized patients. 301 patients with normal potassium levels had potassium controls after bowel cleansing, of whom 71 (23.6%) developed hypokalemia. A logistic regression model showed that diuretic users were more likely to develop hypokalemia than those who did not use diuretics. CONCLUSIONS: Hypokalemia is frequently encountered after low-volume polyethylene glycol bowel cleansing in high-risk patients. Additional large-scale studies are needed on the prevalence of hypokalemia in unselected populations undergoing bowel cleansing and on the occurrence of potentially very serious side effects in order to decide on screening of high-risk groups in daily clinical practice. (Clinical trial registration number: NTR5400.).

Post-Colonoscopy Complications: A Systematic Review, Time Trends, and Meta-Analysis of Population-Based Studies.

OBJECTIVES: Many studies around the world addressed the post-colonoscopy complications, but their pooled prevalence and time trends are unknown. We performed a systematic review and meta-analysis of population-based studies to examine the pooled prevalence of post-colonoscopy complications ("perforation", "bleeding", and "mortality"), stratified by colonoscopy indication. Temporal variability in the complication rate was assessed. METHODS: We queried Pubmed, Embase, and the Cochrane library for population-based studies examining post-colonoscopy complications (within 30 days), performed from 2001 to 2015 and published by 1 December 2015. We determined pooled prevalence of perforations, post-colonoscopy bleeding, post-polypectomy bleeding, and mortality. RESULTS: We retrieved 1,074 studies, of which 21 met the inclusion criteria. Overall, pooled prevalences for perforation, post-colonoscopy bleeding, and mortality were 0.5/1,000 (95% confidence interval (CI) 0.4-0.7), 2.6/1,000 (95% CI 1.7-3.7), and 2.9/100,000 (95% CI 1.1-5.5) colonoscopies. Colonoscopy with polypectomy was associated with a perforation rate of 0.8/1,000 (95% CI 0.6-1.0) and a post-polypectomy bleeding rate of 9.8/1,000 (95% CI 7.7-12.1). Complication rate was lower for screening/surveillance than for diagnostic examinations. Time-trend analysis showed that post-colonoscopy bleeding declined from 6.4 to 1.0/1,000 colonoscopies, whereas the perforation and mortality rates remained stable from 2001 to 2015. Overall, considerable heterogeneity was observed in most of the analyses. CONCLUSIONS: Worldwide, the post-colonoscopy complication rate remained stable or even declined over the past 15 years. The findings of this meta-analysis encourage continued efforts to achieve and maintain safety targets in colonoscopy practice.

Epidemiological, clinical and endoscopic characteristics of colorectal neuroendocrine neoplasms: a population-based study in the Netherlands.

Background and study aims Neuroendocrine neoplasms (NEN) account for a small number of colorectal neoplasms. Endoscopic detection is essential for diagnosis, treatment and follow-up. Little is known about incidence of NENs in colonoscopy populations or the relationship between clinical, endoscopic and histopathologic features. We evaluated epidemiology, endoscopic and clinical characteristics of colorectal NENs in a population-based cohort. Patients and methods Medical records of NEN cases were cross-linked with the national pathology database from January 2001 to December 2015, in South Limburg County, the Netherlands, covering four endoscopy units. Senior pathologists reviewed and classified NENs using World Health Organization 5th edition (2019) guidelines. Results The number of colorectal NEN diagnoses was stable over time with 0.6 NEN per 1,000 patients. A total of NENs were detected in 85 patients: 65 neuroendocrine tumors (NETs) and 20 poorly differentiated neuroendocrine carcinomas (NECs). Rectal NETs were usually small sessile/submucosal lesions with yellowish (lipoma-like) color. Colonic NETs were larger sessile/submucosal lesions with darker color compared to background. Colorectal NECs presented as large, dark-colored lesions with ulcerated/necrotizing areas. Conclusions Our population-based data point to a stable and low incidence of 0.6 NEN per 1,000 patients in the Netherlands. Rectal NETs mainly present as small sessile yellowish lesions. Colonic NETs present as larger and darker lesions than background mucosa and NECs as darker lesions than background with ulceration/necrosis. Standardized endoscopic characterization of colorectal NENs is necessary to improve recognition of these lesions and provide a basis for evidence-based treatment and surveillance recommendations.

Effects of a Personalized Smartphone App on Bowel Preparation Quality: Randomized Controlled Trial.

BACKGROUND: Adequate bowel preparation is essential for the visualization of the colonic mucosa during colonoscopy. However, the rate of inadequate bowel preparation is still high, ranging from 18% to 35%; this may lead to a higher risk of missing clinically relevant lesions, procedural difficulties, prolonged procedural time, an increased number of interval colorectal carcinomas, and additional health care costs. OBJECTIVE: The aims of this study are to compare bowel preparation instructions provided via a personalized smartphone app (Prepit, Ferring B V) with regular written instructions for bowel preparation to improve bowel preparation quality and to evaluate patient satisfaction with the bowel preparation procedure. METHODS: Eligible patients scheduled for an outpatient colonoscopy were randomized to a smartphone app group or a control group. Both the groups received identical face-to-face education from a research physician, including instructions about the colonoscopy procedure, diet restrictions, and laxative intake. In addition, the control group received written information, whereas the smartphone app group was instructed to use the smartphone app instead of the written information for the actual steps of the bowel preparation schedule. All patients used bisacodyl and sodium picosulfate with magnesium citrate as laxatives. The quality of bowel preparation was scored using the Boston Bowel Preparation Scale (BBPS) by blinded endoscopists. Patient satisfaction was measured using the Patient Satisfaction Questionnaire-18. RESULTS: A total of 87 patients were included in the smartphone app group and 86 in the control group. The mean total BBPS score was significantly higher in the smartphone app group (mean 8.3, SD 0.9) than in the control group (mean 7.9, SD 1.2; P=.03). The right colon showed a significantly higher bowel preparation score in the smartphone app group (mean 2.7, SD 0.5 vs mean 2.5, SD 0.6; P=.04). No significant differences were observed in segment scores for the mean transverse colon (mean 2.8, SD 0.4 vs mean 2.8, SD 0.4; P=.34) and left colon (mean 2.8, SD 0.4 vs mean 2.6, SD 0.5; P=.07). General patient satisfaction was high for the smartphone app group (mean 4.4, SD 0.7) but showed no significant difference when compared with the control group (mean 4.3, SD 0.8; P=.32). CONCLUSIONS: Our personalized smartphone app significantly improved bowel preparation quality compared with regular written instructions for bowel preparation. In particular, in the right colon, the BBPS score improved, which is of clinical relevance because the right colon is considered more difficult to clean and the polyp detection rate in the right colon improves with improvement of bowel cleansing of the right colon. No further improvement in patient satisfaction was observed compared with patients receiving regular written instructions. TRIAL REGISTRATION: ClinicalTrials.gov NCT03677050; https://clinicaltrials.gov/ct2/show/NCT03677050.

Safety of low-volume PEG-asc bowel cleansing preparation for colonoscopy: identifying patients at risk for hypokalemia in a prospective cohort study.

Background and study aims The aim of bowel cleansing preparation should be high-quality results and conformance with safety standards. Previously, we reported that hypokalemia occurred in 23.6 % of patients after bowel preparation in a high-risk population on diuretics or hospitalized and referred for colonoscopy. Here we report on a prospective study in a non-selected colonoscopy cohort to identify patients at risk of developing hypokalemia before and after bowel cleansing with low-volume polyethylene glycol with ascorbic acid (PEG-asc). Patients and methods From January 1 to July 31, 2016, we included all patients undergoing colonoscopy in our institution. Prevalences of hypokalemia before and after PEG-asc bowel cleansing for colonoscopy were calculated and risk factors for developing hypokalemia after PEG-asc bowel cleansing were identified. Results In total, 2011 patients were included in the analysis. Of these, 0.8 % had hypokalemia before bowel cleansing with PEG-asc. After bowel preparation, 5.4 % developed hypokalemia. Of the patients, 281 were considered to have "high cardiac risk." The combination of "high cardiac risk" and hypokalemia was present in 1 % of the initial colonoscopy population. Female sex, colorectal cancer diagnosis, and thiazide use were found to be significant predictors for hypokalemia after use of PEG-asc. No arrhythmias or serious adverse events due to hypokalemia occurred. Conclusions Physicians referring patients for colonoscopy should be aware that "high cardiac risk" patients and those on thiazide diuretics undergoing bowel cleansing for colonoscopy are a risk of developing post-cleansing hypokalemia but it remains to be determined whether their risk of developing life-threatening arrhythmias is truly increased.

Optical diagnosis of diminutive polyps in the Dutch Bowel Cancer Screening Program: Are we ready to start?

Background and study aims Implementation of optical diagnosis of diminutive polyps may potentially increase the efficacy and cost-effectiveness of colonoscopies. To adopt such strategy in clinical practice, the Preservation and Incorporation of Valuable endoscopic Innovations (PIVI) thresholds provide the basis to be met: ≥ 90 % negative predictive value (NPV) for diagnosis of adenomatous histology and ≥ 90 % agreement on surveillance intervals. We evaluated this within the Dutch Bowel Cancer Screening Program (BCSP). Patients and methods Endoscopic and histological data were collected from participants of the national bowel cancer screening program with an unfavorable fecal immunochemical test referred for colonoscopy between February 2014 and August 2015 at four endoscopy centers. The "resect and discard" scenario was studied, resecting diminutive polyps without histological evaluation. Agreement between optical diagnosis and histological diagnosis was measured for surveillance intervals according to Dutch, European and American post-polypectomy surveillance guideline. Results Fifteen certified endoscopists participated in this study and included 3028 diminutive polyps. In 2,330 patients both optical and histological diagnosis were available. Optical diagnosis of diminutive polyps showed NPV of 84 % (95 % CI 80-87) for adenomatous histology in the rectosigmoid. Applying the 'resect and discard' strategy resulted in 90.6 %, 91.2 %, 90.9 % agreement on surveillance intervals for the Dutch, European and American guideline respectively. Conclusion Our data representing current clinical practice in the Dutch BCSP practice on optical diagnosis of diminutive polyps showed that accuracy of predicting histology remains challenging, and risk of incorrect optical diagnosis is still significant. Therefore, it is too early to safely implement these strategies.