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Use of pressure release valve to prevent colonic injury during colonoscopy.

Although bowel perforation during colonoscopy is often related to direct endoscopic pressure or injury in the rectosigmoid area, colonic perforation has been also reported with overinflation of air. This latter type of rupture appears related to formation of a blind loop, to an overly competent ileocecal valve that prohibits colonic decompression, or to use of particular power sources that generate unsafe pressure levels. In an effort to obviate this pneumatic type of rupture, the authors tested a pressure release valve developed by the Olympus Corporation that supplants the standard air-water valve in available Olympus colonoscopes. Use of this valve revealed a significant difference in mean and maximal intracolonic pressures generated during colonoscopy. Moreover, its use resulted in a marked decrease in tissue damage in the pneumatically inflated cadaver colon. Incorporation of such a pressure release valve into available colonoscopes should reduce the risk of pneumatic colon rupture and improve the safety of diagnostic colonoscopy.

Air Pressure↗

Evaluation of rapid colonoscopy preparation using a new gut lavage solution.

The traditional colonoscopy preparation of laxatives and enemas requires 2 days to complete and is occasionally unsatisfactory. The alternative method, gut lavage with saline-based solutions, is hazardous in elderly or compromised patients because of overhydration. We studied a new, orally ingested electrolyte solution containing sodium sulfate and polyethylene glycol as preparation for elective colonoscopy in a consecutive series of 43 patients. Almost all patients achieved a good to excellent preparation. There were no changes in fluid or electrolyte balance and no complications of the procedure. Colonoscopy preparation with this technique is rapid, effective, and well tolerated and is a safe alternative to the standard approach.

Administration, Oral↗

Is lumbar epidural analgesia an alternative in patients who have incomplete colonoscopy with standard premedication?

Total colonoscopy is unsuccessful in about 10% of attempts. In three fourths of the cases, failure is due to the patient's inability to tolerate the procedure and difficulty in negotiating the sigmoid colon. Lumbar epidural analgesia has been used in a series of 29 patients referred for total colonoscopy which had been unsuccessful using intravenous analgesia. The cecum was reached in 27 of 29 examinations. Mean time required to perform total colonoscopy was 10 min and took less than 5 min in one third of the cases. Complete visceral analgesia was responsible for one case of perforation.

Adolescent↗

Explosion-safe, enema-free, nutritious colonoscopy preparation using a prepackaged formula diet.

Breath hydrogen and methane concentrations were normal before morning colonoscopy in 72 ambulatory patients randomly assigned to Ensure or clear liquid diet preparation for 48 hours. Mechanical bowel preparation was equal with each diet using an evening-laxative and morning-enema regimen and with Ensure using two consecutive evenings of laxatives without enemas. Ensure is an explosion-safe, mechanically acceptable, nutritionally adequate method of colonoscopy preparation. With a suitable laxative, Ensure eliminates the need for enemas in colonoscopy preparation.

Adult↗

Salmonella newport infections transmitted by fiberoptic colonoscopy.

During a 2-week period following the colonoscopy and biopsy of a patient with acute Salmonella newport gastroenteritis, S. newport was recovered from colonic aspirates or fecal specimens of eight of 28 patients from whom specimens were cultured during or after colonoscopy. Two of the eight persons from whom S. newport was isolated developed acute gastroenteritis, two had asymptomatic infections, and four had positive aspirates collected through a colonoscope but did not become infected. Although S. newport was never recovered from the four colonoscopes used during the outbreak, cultures of one of the colonic biopsy forceps grew S. newport. Contamination of the equipment most likely occurred during colonoscopy of the index patient. Inadequate disinfection of the equipment allowed the organism to survive and possibly to cross-contaminate other colonoscopes, and the organism was then transmitted to other patients by use of the contaminated colonoscopes or the contaminated biopsy forceps. Implemented control measures terminated the outbreak.

Adult↗

The effectiveness of simethicone in improving visibility during colonoscopy: a double-blind randomized study.

The effect of simethicone in improving visibility during colonoscopy was randomly studied in 97 patients receiving either simethicone (N = 49) or placebo (N = 48) in a colon lavage solution. Visibility was assessed by the amount of bubbles and the degree of haziness noted during colonoscopy. The degree of bubbles was scored on a scale of 0 to 3, and haziness was scored on a scale of 0 to 2. Patients receiving simethicone had significantly less bubbles (p less than 0.001) and less haziness (p less than 0.01) in the colon when compared to placebo-treated patients. These data indicate that the addition of simethicone to the colonic lavage solution results in improved colonic visibility and may result in technically easier and more accurate colonoscopy.

Clinical Trials as Topic↗

Limited benefit of atropine as premedication for colonoscopy.

A prospective double-blind trial was performed comparing atropine (0.5 mg) by slow intravenous administration to placebo as premedication for colonoscopy, to assess the possible beneficial effects of this vagolytic agent on the performance and safety of the procedure. A total of 77 patients was randomly assigned to receive atropine (38 patients) or placebo (39 patients) before colonoscopy in conjunction with our standard initial medications for conscious sedation (meperidine, 0.4 mg/kg and midazolam, 0.03 mg/kg). Total procedure time was 31 min for the atropine group and 35 min for the placebo group (p greater than 0.05), and there was no overall difference in the total amount of intra-procedural medications required. No statistically significant differences were observed relative to the number or severity of vagal episodes, and neither the endoscopist nor the patients noted any differences in the ease or tolerance of the procedure (p greater than 0.05). Although these results fail to demonstrate a significant benefit of atropine when given routinely as premedication for colonoscopy, this study does not rule out the potential usefulness of atropine in counteracting vagal episodes when they occur.

Arrhythmias, Cardiac↗

Barium enema versus colonoscopy for patients with polyps found during flexible sigmoidoscopy.

This prospective study compares the accuracy of barium enema examination performed by experienced radiologists to colonoscopy performed by experienced gastroenterologists blinded to the radiographic findings to detect proximal, synchronous lesions in patients with polyps detected during fiberoptic sigmoidoscopy. Three thousand six patients were examined, of whom 147 (5%) had polyps larger than 0.5 cm in diameter. Of 114 patients who completed the protocol, 46 patients (40%) had synchronous, proximal colonic lesions. There were no radiographic false positives, but the single-contrast barium enema missed polyps in 13 while detecting polyps in 2 patients (sensitivity = 13%). The double-contrast barium enema missed proximal polyps in 23 patients while detecting them in 8 (sensitivity = 26%). We conclude that patients with neoplastic polyps found during fiberoptic sigmoidoscopy should have colonoscopy without barium enema. If the entire colon cannot be examined at colonoscopy, we advise double-contrast barium enema.

Adenocarcinoma↗

Addition of senna improves colonoscopy preparation with lavage: a prospective randomized trial.

Attempts have been made to further improve the widely performed colonoscopy preparation with lavage. In a prospective study, 120 outpatients and inpatients scheduled for total colonoscopy were randomized to two preparatory regimens. The day before endoscopy either extractum sennae (N = 60) or a placebo solution (N = 60) was given. Just before examination all patients underwent whole gut irrigation with a polyethylene glycol electrolyte lavage solution (PEG-ELS). Adequacy of preparation, patient tolerance, and the necessary amount of PEG-ELS were assessed. Physician assessment of colon cleansing showed superiority in the group with additional laxative. The colon was free of solid debris in 66.7% of patients after PEG-ELS and in 90% after senna/PEG-ELS administration (p less than 0.01). Patient tolerance was similar in both groups with 86.7% vs. 83.3% of subjects rating the preparation as tolerable. Severe adverse events were not observed. In the senna/PEG-ELS group, significantly less (p less than 0.05) lavage fluid was needed. We conclude that the combination of senna and PEG-ELS is more effective than PEG-ELS in cleansing the colon for colonoscopy.

Adolescent↗

Combustible colonic gas levels during flexible sigmoidoscopy and colonoscopy.

To what extent the standard preparation for sigmoidoscopy (phosphosoda enemas) makes the bowel safe for electrocautery is unknown. Sixty patients were prospectively evaluated to compare the presence of the combustible gases hydrogen and methane during colonoscopy and flexible sigmoidoscopy. Thirty patients underwent flexible sigmoidoscopy after phosphosoda enema preparation, and 30 patients underwent colonoscopy after a polyethylene glycol solution preparation. During colonoscopy, the concentrations of hydrogen and methane remained below combustible levels in all patients. Even segments of colon with significant fecal matter present did not have combustible levels of these two gases. However, at flexible sigmoidoscopy, combustible levels of hydrogen and methane were measured in 3 of 30 (10%) patients. Due to the risk of explosion, electrocautery should not be performed during routine flexible sigmoidoscopy after the standard phosphosoda enema preparation.

Administration, Oral↗

Colonoscopy and endoscopic therapy for delayed post-polypectomy hemorrhage.

Nine consecutive patients in whom endoscopic management of delayed post-polypectomy hemorrhage was attempted are described. Each patient presented with active rectal bleeding 12 hours to 12 days after snare resection of a colon polyp. In each patient, repeat colonoscopy identified the bleeding site and various combinations of injection therapy, electrocautery, or thermal injury led to cessation of hemorrhage. No complications resulted from repeat colonoscopy and endoscopic therapy. Colonoscopy and endoscopic therapy is feasible, effective, and safe in selected patients with active delayed post-polypectomy hemorrhage.

Colonic Polyps↗

Risk factors associated with vasovagal reactions during colonoscopy.

To define the syndrome of vasovagal reactions that occur during colonoscopy and to identify those risk factors associated with this development, we prospectively evaluated patients undergoing colonoscopy with monitored sedation. A total of 223 consecutive patients were evaluated during the 60-day study period. A vasovagal reaction was defined as the occurrence of one or more of the following: diaphoresis, sustained bradycardia of less than 60 beats/min or a decrease in heart rate of 10%, or hypotension (systolic blood pressure less than 90 mm Hg, diastolic blood pressure less than 60 mm Hg, or a reduction in blood pressure of more than 10% below a baseline measurement before colonoscopy and after sedation). Thirty-seven (16.5%) of the 223 patients experienced a vasovagal reaction by our criteria. The remaining 186 patients did not; 100 of these patients were randomly selected by computer to form a control group. No statistically significant differences were observed between the vasovagal and control groups with regard to demographics, cardiopulmonary disease, cardiac medications, procedure success, the endoscopist, patient procedure tolerance, colon preparation, or procedure difficulty. A significant difference was seen in the mean dose of midazolam used in the vasovagal group as compared with that used in the control group (4.6 mg versus 3.9 mg, p < 0.04), and moderate to severe diverticulosis was more commonly seen in the vasovagal group as compared with the control group (43% versus 16%, p < 0.02). Thirteen (35%) of the 37 patients who had a vasovagal reaction required medical intervention (5.8% of the 223 patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Bradycardia↗

The effectiveness of simethicone in improving visibility during colonoscopy when given with a sodium phosphate solution: a double-bind randomized study.

BACKGROUND: Oral sodium phosphate solution is better tolerated than polyethylene glycol when used for colonoscopy preparation, but visibility of the lumen can be impaired because of the presence of bubbles. METHODS: We studied 86 patients receiving either simethicone (n = 42) or placebo (n = 44) in addition to oral sodium phosphate to determine if simethicone improved visibility during colonoscopy. Colonoscopy was performed by a single blinded investigator. Five areas of the colon (rectosigmoid, descending, transverse, ascending, and cecum) were assessed for the presence of bubbles on withdrawal of the endoscope. Bubbles were scored as follows: 0, minimal or none; 1, covering half the lumen; 2, covering the entire circumference; 3 filling the entire lumen. RESULTS: Thirteen patients in the placebo group and only one in the simethicone had significant bubbles ( > or = 1). Additionally, the mean bubble scores were greater in the placebo group in each region of the colon (p < or = 0.05 in rectosigmoid and ascending colon). CONCLUSIONS: This study indicates that taking simethicone with an oral sodium phosphate preparation can improve colonic visibility by diminishing the presence of bubbles. Better visualization could improve detection of mucosal pathologic lesions.

Administration, Oral↗

Sedation and analgesia for colonoscopy: patient tolerance, pain, and cardiorespiratory parameters.

BACKGROUND: Colonoscopy is generally performed with the patient sedated and receiving analgesics. However, the benefit of the most often used combination of intravenous midazolam and pethidine on patient tolerance and pain and its cardiorespiratory risk have not been fully defined. METHODS: In this double-blind prospective study, 150 outpatients undergoing routine colonoscopy were randomly assigned to receive either (1) low-dose midazolam (35 micrograms/kg) and pethidine (700 micrograms/kg in 48 patients, 500 micrograms/kg in 102 patients), (2) midazolam and placebo pethidine, or (3) pethidine and placebo midazolam. RESULTS: Tolerance (visual analog scale, 0 to 100 points: 0 = excellent; 100 = unbearable) did not improve significantly more in group 1 compared with group 2 (7 points; 95% confidence interval [-2-17]) and group 3 (2 points; 95% confidence interval [-7-12]). Similarly, pain was not significantly improved in group 1 as compared with the other groups. Male gender (p < 0.001) and shorter duration of the procedure (p = 0.004), but not amnesia, were associated with better patient tolerance and less pain. Patient satisfaction was similar in all groups. Oxygen desaturation and hypotension occurred in 33% and 11%, respectively, with a similar frequency in all three groups. CONCLUSIONS: In this study, the combination of low-dose midazolam and pethidine does not improve patient tolerance and lessen pain during colonoscopy as compared with either drug given alone. When applying low-dose midazolam, oxygen desaturation and hypotension do not occur more often after combined use of both drugs. For the individual patient, sedation and analgesia should be based on the endoscopist's clinical judgement.

Adult↗

Meta-analysis and cost comparison of polyethylene glycol lavage versus sodium phosphate for colonoscopy preparation.

BACKGROUND: Although polyethylene glycol lavage solutions are widely used for colonoscopy preparation, evidence suggests that sodium phosphate is better tolerated and has similar efficacy. The purpose of this study was to compare compliance with and efficacy of polyethylene glycol and sodium phosphate using meta-analysis and to compare the cost of colonoscopy with both methods. METHODS: We used Medline to identify all randomized controlled trials comparing the two preparations. Study methods were evaluated, and quantitative data were abstracted independently, including inability to complete the preparation and preparation quality, rated as adequate or excellent. A random effects model was used to calculate the pooled relative risk. Direct costs and literature-based probability estimates were used to compare costs. RESULTS: Among 1286 subjects from eight colonoscopist-blinded trials, the pooled relative risk of inability to complete the preparation was 0.23 (95% CI [0.18-0.28]) in favor of sodium phosphate. Although the best estimate of the relative risk for an adequate quality preparation revealed therapeutic equivalence (relative risk = 1.06: 95% CI [0.95-1.19]), an excellent quality preparation was more likely with sodium phosphate (relative risk = 1.72: 95% CI [1.16-2.53]). Assuming reexamination rates from published literature of 3% and 8% for sodium phosphate and polyethylene glycol, respectively, direct costs of colonic examination were $465 and $503. There were no clinically important adverse effects with either method. CONCLUSION: The results suggest that sodium phosphate is as effective and less costly, with a more easily completed preparation, compared with polyethylene glycol and is the preferred method of preparation for colonoscopy for certain patient subgroups.

Adult↗

Reliability of panel-based guidelines for colonoscopy: an international comparison.

BACKGROUND: This study examined the reliability of explicit guidelines developed using the RAND-UCLA appropriateness method. METHODS: The appropriateness of over 400 indications for colonoscopy was rated by two multispecialty expert panels (United States and Switzerland). A nine-point scale was used, which was consolidated into three categories of appropriateness: appropriate, uncertain, inappropriate. The distribution of appropriateness ratings between the two panels and the intrapanel and interpanel agreement for categories of appropriateness were calculated for all possible indications. Similar statistics were calculated for a series of 577 primary care patients referred for colonoscopy in Switzerland. RESULTS: Over 80% of all indications (348) could be directly compared. The proportions of indications classified as appropriate, uncertain, or inappropriate were 28.4%, 24.7%, 46.6% and 33.0%, 23.0%, 44.0% for the U.S. and the Swiss panels, respectively. Interpanel agreement was excellent for all the possible indications (kappa value: 0.75) and lower for actual cases (kappa value: 0.51) because of lower agreement for the most frequently encountered indications. CONCLUSIONS: Good agreement between the two sets of criteria was found, pointing to the reliability of the method. Partial disagreement occurred essentially for a few, albeit frequently encountered, indications for use of colonoscopy in cases of uncomplicated lower abdominal pain or constipation.

Colonoscopy↗

Complications and adverse effects of colonoscopy with selective sedation.

BACKGROUND: Cardiopulmonary adverse effects are commonly observed in patients undergoing colonoscopy with sedation. This study determines the incidence of such events when sedation is given only when required. METHODS: In 2500 consecutive patients, colonoscopies were started without premedication but sedation was offered if significant discomfort occurred. Parameters of blood pressure, heart rate, oxygen saturation and patient appearance were continuously recorded by a nurse assistant. Additional adverse effects occurring during or after the procedure were noted in the patients' protocol. Risk factors for the development of complications were evaluated with the use of a logistic regression model and the odds ratio. RESULTS: Ninety-five percent of all patients required neither sedation nor analgesia. Adverse effects occurred in 59 patients (2. 4%). Twenty-six of these patients (1.0%) had short-lasting episodes of oxygen desaturation and 22 patients (0.9%) experienced vasovagal reactions. Mechanical complications occurred in a total of 8 patients (0.3%) and consisted of 2 perforations and 6 episodes of hemorrhage. In the logistic regression model, impaired physical status was the single most important risk factor for the development of cardiopulmonary complications (odds ratio 4.7; 95% confidence interval [2.0, 11.4]). CONCLUSIONS: In experienced hands, patients undergoing colonoscopy rarely require sedation. If selective sedation is used, cardiopulmonary adverse effects occur in approximately 2% of all patients, most of whom require no medical intervention.

Aged↗

The role of sigmoidoscopy, radiographs, and colonoscopy in the diagnostic evaluation of pediatric age patients with suspected juvenile polyps.

Juvenile polyps are the most common cause of painless hematochezia in pediatric Age patients after the first year of life. This study evaluated the role of rigid proctosigmoidoscopy, air contrast barium enema examinations, and colonoscopy in the diagnostic approach to 43 such patients. During sigmoidoscopy, polyps were removed from 31 children. On subsequent barium enema examination, more proximal lesions were found in only 4 of these 31 patients, but were seen in 7 of the 12 children who had negative sigmoidoscopic evaluations. Fourteen children had colonoscopy performed. This group included the latter 12 patients plus 2 of the former 4 who again developed hematochezia. Polypectomies were done during 11 of these procedures. Eight of these 11 children had proximal lesions seen during radiographic studies. The diagnostic approach to pediatric age patients with painless hematochezia should include an initial rigid sigmoidoscopic examination. Barium enema evaluation should be reserved for those patients requiring colonoscopy. The latter examination should be performed in all children who have had negative sigmoidoscopic examinations plus those who have had polyps removed from the rectum and then again develop hematochezia.

Adolescent↗