We should dampen our enthusiasm for computer-aided detection in colonoscopy: at least for now.
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Editorial↗
Biomedical subjects
Douglas K Rex
Publications and source records attributed to Douglas K Rex.
Technical performance of colonoscopy in patients sedated with nurse-administered propofol.
OBJECTIVES: Nurse-administered propofol has gained attention as a safe and effective means of sedation for patients undergoing endoscopic procedures. However, little is known about the effect of propofol on the technical performance of colonoscopy. METHODS: Three separate studies were conducted. In the first study, we reviewed procedure notes from consecutive colonoscopies performed by a single experienced endoscopist at our hospital endoscopy unit on patients sedated with either nurse-administered propofol (n = 162) or midazolam/narcotic (n = 164). In the second study, 100 eligible colonoscopy outpatients were randomized to receive either nurse-administered propofol (n = 50) or midazolam/fentanyl (n = 50). In both studies, the measured parameters included visualization of the cecum, time required to reach the cecum, repositioning of the patient, and the application of abdominal counterpressure. In a third study, we reviewed the rate of cecal intubation and colonic perforation in the first 2357 patients in our unit receiving nurse-administered propofol. RESULTS: In the retrospective comparative study, there was no difference in the cecal intubation rate in those receiving propofol (99.4%) compared to those receiving midazolam/narcotic (97%; p= 0.1), and three of five failed cecal intubations in the latter group resulted from obstructing masses. Patients sedated with propofol were repositioned less frequently compared to those receiving midazolam/narcotic (3.7%vs 26.2%) (p < 0.0001). Abdominal pressure was employed in 9.9% of patients sedated with propofol compared to 19.5% (p= 0.01) of those given midazolam/narcotic. The mean time to reach the cecum was lower in the propofol group than in the midazolam/narcotic group (4.6 min vs 6.0 min, p= 0.002). In the prospective randomized study, the endoscopist intubated the cecum in all 100 patients. Patients in the propofol group were repositioned less frequently than those in the midazolam/fentanyl group (2%vs 24%, respectively, p= 0.001). The number of cases requiring abdominal counterpressure was not significantly different between the propofol and midazolam/fentanyl groups (12%vs 24%, respectively, p= 0.1). The mean time to reach the cecum in the propofol group (3.2 min) was similar to that in the midazolam/fentanyl group (3.8 min, p= 0.08). Among the first 2357 patients in our unit undergoing colonoscopy with nurse-administered propofol, the rate of complete colonoscopy was 99.2% and there were no perforations. CONCLUSION: Nurse-administered propofol sedation is safe and simplifies the technical performance of colonoscopy compared to midazolam/narcotic sedation.
Analgesics, Opioid↗
Is virtual colonoscopy ready for widespread application?
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Colonic Polyps↗
Bowel obstruction and pseudo-obstruction.
The gastroenterologist is frequently involved in the care of patients with bowel obstruction and pseudo-obstruction. In the case of obstruction, the central problem is determining which patients should be managed surgically. In both SBO and LBO, evidence of vascular compromise to the gut mandates surgical intervention. Most patients with pseudo-obstruction respond to conservative therapy or neostigmine. Endoscopic decompression is indicated in recalcitrant cases, with surgery reserved as a last resort.
Algorithms↗
Screening for Barrett's esophagus in colonoscopy patients with and without heartburn.
BACKGROUND & AIMS: The population prevalence of Barrett's esophagus (BE) is uncertain. Our aim was to describe the prevalence of BE in a volunteer population. METHODS: Upper endoscopy (EGD) was performed in 961 persons with no prior history of EGD who were scheduled for colonoscopy. Symptom questionnaires were completed prior to endoscopy. Biopsy specimens were taken from the gastric cardia and any columnar mucosa extending > or =5 mm into the tubular esophagus and from the stomach for H. pylori infection in the last 812 patients. RESULTS: The study sample was biased toward persons undergoing colonoscopy, males, and persons with upper GI symptoms. The prevalence of BE was 65 of 961 (6.8%) patients, including 12 (1.2%) with long-segment BE (LSBE). Among 556 subjects who had never had heartburn, the prevalences of BE and LSBE were 5.6% and 0.36%, respectively. Among 384 subjects with a history of any heartburn, the prevalences of BE and LSBE were 8.3% and 2.6%, respectively. In a univariate analysis, LSBE was more common in those with any heartburn vs. those with no heartburn (P = 0.01), but the sample size was insufficient to allow multivariate analysis of predictors of LSBE. In a multivariate analysis, BE was associated with increasing age (P = 0.02), white race (P = 0.03), and negative H. pylori status (P = 0.04). Overall, BE was not associated with heartburn, although heartburn was more common in persons with LSBE or circumferential short segments. CONCLUSIONS: LSBE is very uncommon in patients who have no history of heartburn. SSBE is relatively common in persons age > or =40 years with no prior endoscopy, irrespective of heartburn history.
Adult↗
Colonoscopy practice variation.
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Colonoscopy↗
Colonoscopic identification of a foreign body causing an hepatic abscess.
BACKGROUND: Hepatic abscesses often result from a perforation of the gastrointestinal tract. Although rare, this may occur via puncture by a foreign body. The object may directly extend from the stomach or duodenum into the liver, or rarely, the object may perforate the bowel distal to the duodenum and indirectly extend to the liver leading to the formation of an abscess. CASE REPORT: A 44-year-old man developed an hepatic abscess. Although the abscess was identified on computed tomography, various imaging studies were unable to identify the cause of the infection. After an extended ICU course, the patient was deemed stable enough to undergo a colonoscopy that demonstrated a foreign body penetrating through the wall of the sigmoid colon. CONCLUSIONS: Here we describe the first report of a foreign body leading to a hepatic abscess where the object was identified by colonoscopy. In addition, we present a comprehensive literature review examining the method of identification of gastrointestinal foreign bodies that led to liver abscesses. These findings emphasize that in cases of hepatic abscesses of unknown etiology, direct visualization by colonoscopy may be a useful tool to elucidate the cause of the abscess.
Adult↗
Endoscopic findings of diverticular inflammation in colonoscopy patients without clinical acute diverticulitis: prevalence and endoscopic spectrum.
OBJECTIVE: Experienced colonoscopists sometimes encounter endoscopic findings of diverticular inflammation in patients without clinical evidence of acute diverticulitis. Our aim was to describe the spectrum and prevalence of such endoscopic findings in a consecutive series of patients undergoing colonoscopy. METHODS: During elective colonoscopy performed by a single endoscopist on 2566 consecutive outpatients, 21 patients were identified with endoscopic evidence of diverticular inflammation. RESULTS: Endoscopic findings included erythema and edema of a diverticular opening (n = 8), pus emanating from a diverticular orifice (n = 8), and a polypoid mass of granulation tissue in a diverticular orifice (n = 15). Follow-up was obtained by telephone in 17 patients at a mean of 11.9 months after colonoscopy. Only one patient had symptoms of diverticulitis at the time of colonoscopy. This patient improved with antibiotic therapy. Six of the 21 patients had experienced symptoms of abdominal pain or fever, but only one had a diagnosed episode of acute diverticulitis before colonoscopy. None of the patients had acute diverticulitis during the follow-up interval. CONCLUSIONS: Endoscopic findings of diverticular inflammation were identified in about 0.8% of patients undergoing colonoscopy without clinical evidence of diverticulitis. Most patients are asymptomatic at the time of colonoscopy, and antibiotic therapy is generally unnecessary.
Academic Medical Centers↗
Accessing proximal aspects of folds and flexures during colonoscopy: impact of a pediatric colonoscope with a short bending section.
OBJECTIVE: Accessing the proximal sides of colorectal folds, flexures, and valves can be difficult endoscopically and can contribute to missed lesions and failed therapeutic procedures. The aim of this study was to determine whether a prototype colonoscope with a short bending section could facilitate accessing difficult to reach areas proximal to folds, flexures, and valves. METHODS: In a nonrandomized study, the prototype colonoscope, a standard pediatric colonoscope, and a standard adult colonoscope were used to attempt retroflexion in the cecum and, if unsuccessful, in the right colon. RESULTS: The prototype colonoscope allowed cecal retroflexion, including clear visualization of the ileocecal valve and the cecal mucosa medial to the valve, in 95% of attempts. A standard pediatric colonoscope was successful in 50% and a standard adult colonoscope in 24.5%. The prototype was more successful than both the standard pediatric (p < 0.001) and the standard adult instrument (p < 0.001). The standard pediatric colonoscope was successful more often than the standard adult colonoscope (p = 0.02). CONCLUSIONS: Using the ability to retroflex in the cecum as a surrogate marker, a prototype pediatric colonoscope with a short bending section seems to facilitate retroflexion and visualization of the proximal aspects of difficult to see regions in the proximal colon.
Colon↗
Wireless capsule endoscopy detects small bowel ulcers in patients with normal results from state of the art enteroclysis.
BACKGROUND: Wireless capsule endoscopy (WCE) is a new technology for small bowel imaging. AIM: To report our initial experience with sensitivity of high quality enteroclysis in patients with small bowel ulcers detected by WCE. METHODS: Medical records of all patients referred for WCE from December, 2001 to April, 2002 at our institution were reviewed. All patients had negative upper and lower endoscopies and small bowel barium studies before WCE. RESULTS: There were 40 patients (19 female, mean age 57.3 yr) during this study period. Three patients had multiple small bowel ulcers detected by WCE. One with ileal ulcers and abdominal pain had an enteroclysis at another hospital before WCE. Review of the study at our institution showed that it was of excellent quality and was normal. Two patients with chronic iron deficiency anemia had multiple small bowel ulcers and were referred after WCE for a repeat small bowel barium study by biphasic enteroclysis performed by experienced GI radiologists. The radiologists were told in advance of the WCE findings. Both studies were considered technically to be of perfect quality. Despite this, both studies were negative. All 3 patients improved after therapy for Crohn's disease. CONCLUSIONS: Our data indicates that WCE may be more sensitive for small bowel ulcers than the best enteroclysis available.
Adolescent↗
Nurse-administered propofol sedation without anesthesia specialists in 9152 endoscopic cases in an ambulatory surgery center.
Narcotics and benzodiazepines are commonly used for sedation for endoscopy in the United States. Propofol has certain advantages over narcotics and benzodiazepines, but its use is often controlled by anesthesia specialists. This report describes our experience with dosage, safety, patient satisfaction, and discharge time with nurse-administered propofol sedation in 9152 endoscopic cases. The study was performed in a private practice ambulatory surgery center in Medford, Oregon. With the assistance of an anesthesiologist, we developed a protocol for administration of propofol in routine endoscopic cases, in which propofol was given by registered nurses under the supervision of endoscopists or gastroenterologists. We then applied the protocol with 9152 patients. There were seven cases of respiratory compromise (three prolonged apnea, three laryngospasm, one aspiration requiring hospitalization), all associated with upper endoscopy. Five patients required mask ventilation, but none required endotracheal intubation. There were seven colonic perforations (<1 per 1000 colonoscopies), of which three may have involved forceful sigmoid disruption. Of patients who had previously received narcotic or benzodiazepine sedation, 84% preferred propofol. Gastroenterologists strongly preferred propofol. The mean time from completion of procedures to discharge in a sample of 100 patients was 18 min.Nurse-administered propofol sedation in an ambulatory surgery center was safe and resulted in high levels of patient satisfaction and rapid postprocedure recovery and discharge.
Adolescent↗
Wide angle colonoscopy with a prototype instrument: impact on miss rates and efficiency as determined by back-to-back colonoscopies.
OBJECTIVE: Polyps are missed during conventional colonoscopy, even with meticulous technique. The aim of this study was to investigate whether a prototype wide angle colonoscope is associated with a reduced miss rate for polyps. METHODS: Two studies were performed. In study 1, a total of 50 patients underwent back-to-back, same-day colonoscopy by a single examiner with the prototype wide angle colonoscope and with a standard colonoscope, with the order of scopes randomized. In study 1, an attempt was made to keep examination time with the two colonoscopes equal. In study 2, a total of 20 patients were examined, 10 by the same colonoscopist who performed study 1 and 10 by a second colonoscopist. In study 2, examiners tried to perform the examinations as quickly as accuracy would allow. RESULTS: In study 1, the miss rate for all polyps was lower with the wide angle colonoscope (20% vs 31%; p = 0.046), although the mean examination time with the wide angle instrument was shorter (6.75 min vs 7.64 min; p = 0.0005). There was no significant difference in detection of adenomas. Polyps, including adenomas, were missed in the peripheral endoscopic field more frequently with the standard colonoscope. In study 2, wide angle colonoscopy was associated with reductions in examination time of 25% and 30% for the two examiners, respectively. Miss rates were the same for one colonoscopist but were higher for the other colonoscopist when the wide angle instrument was used. CONCLUSION: A prototype wide angle colonoscope did not eliminate polyp miss rates. Wide angle colonoscopy has the potential to reduce examination time and improve visualization of the periphery of the endoscopic field of view, but improvements in resolution are needed.
Adult↗
Nurse-administered propofol versus midazolam and meperidine for upper endoscopy in cirrhotic patients.
OBJECTIVES: Upper GI endoscopy is often performed in patients with chronic liver disease to screen for esophageal and gastric varices. Propofol is currently under evaluation as an alternative to the combination of midazolam and meperidine for sedation during endoscopic procedures. The purpose of this study was to compare nurse-administered propofol to midazolam and meperidine for sedation in patients with chronic liver disease undergoing diagnostic upper GI endoscopy. METHODS: Twenty outpatients who had known chronic liver disease (Child-Pugh class A or B) and were undergoing variceal screening were randomized to receive propofol or midazolam plus meperidine for sedation. Administration of sedation was performed by a registered nurse and supervised by the endoscopist. Outcome measures studied were induction and recovery times, efficacy and safety of sedation, patient satisfaction, and return to baseline function. RESULTS: The mean dose of propofol and meperidine/midazolam administered was 203 mg (SD 43.7, range 150-280) and 71.3 mg (SD 17.7, range 50-100)/5.3 mg (SD 0.9, range 3.0-6.0), respectively. The mean time to achieve adequate sedation was 3.6 min (SD 1.2) for the propofol group in comparison to 7.3 min (SD 2.8) for the meperidine/midazolam group (p<0.05). Procedure times between the groups were similar: propofol, 3.9 min (SD 1.9); midazolam/meperidine, 2.7 min (SD 0.8) (p=0.11). The level of sedation achieved by the propofol group was greater (p=0.0001). Time to full recovery was faster in the propofol group: 34.9 min (SD 10.3) versus 51.6 min (SD 18.4) (p<0.05). The mean time to reach a maximal level of alertness on the Observer's Assessment of Alertness and Sedation Scale for the propofol group was 15 min (SD 3.6) versus 29 min (SD 10.5) (p=0.001). Although both groups recorded a high level of satisfaction, patients receiving propofol expressed greater overall mean satisfaction with the quality of their sedation at the time of discharge (p<0.05), and reported a return to baseline function sooner in the majority of cases. Propofol achieved comparable levels of efficacy and safety to meperidine/midazolam in our study group. Both were well tolerated with minimal complications. CONCLUSIONS: Propofol sedation administered by registered nurses in the setting of adequate patient monitoring is efficacious and well tolerated in patients with liver disease who are undergoing variceal screening by upper endoscopy. Patients were more satisfied with the quality of sedation, and return to baseline function was usually sooner compared to results achieved with midazolam/meperidine. Propofol offers advantages over meperidine/midazolam in cirrhotic patients.
Aged↗
Performance of Given suspected blood indicator.
OBJECTIVES: Given Imaging (Yoqneam, Israel) has developed a suspected blood indicator (SBI) function for its wireless capsule endoscopy (WCE) software. The SBI detects blood and marks appropriate images for interrogation. The sensitivity and accuracy of SBI and its role in examining WCE studies is unknown. Our aim was to evaluate the accuracy of this new software in detecting small bowel lesions. METHODS: WCE reports of all patients referred for WCE in October and November, 2002, were reviewed. The images from each patient were reviewed by experienced gastroenterologists at 15 frames/s. The findings detected by gastroenterologists were compared to those recognized by SBI. Arteriovenous malformations (AVMs), ulcers, erosions, and sites of active bleeding were considered significant lesions. RESULTS: A total of 24 patients (16 women and eight men, mean age 59 yr) were studied during this period. The indications for the study were iron deficiency anemia in 18 patients and abdominal pain in six patients. A total of 109 lesions were identified by gastroenterologists (47 AVMs, 18 active bleeding ulcers, 18 ulcers without bleeding, and 26 erosions). Active bleeding seen by gastroenterologists was secondary to AVMs (five cases), jejunal ulcers (11 cases, all in the same patient), and gastric ulcers (two cases). A total of 31 potential areas of blood were identified by SBI. When compared to those findings recognized by gastroenterologists, 28 lesions were correctly identified (six AVMs, 13 active bleeding ulcers, (three AVMs and 10 jejunal ulcers), seven nonbleeding ulcers, and two nonbleeding erosions. The overall sensitivity, positive predictive value, and accuracy of SBI to detect significant small bowel lesions were 25.7%, 90%, and 34.8%, respectively. If only actively bleeding lesions in the small bowel were considered, SBI had sensitivity, positive predictive value, and accuracy of 81.2%, 81.3%, and 83.3%, respectively. CONCLUSIONS: SBI has good sensitivity and positive predictive value for actively bleeding lesions in the small bowel. Complete review of the study by the physician is still needed. SBI should be considered as a complementary and rapid screening tool for gastroenterologists to identify actively bleeding lesions.
Chi-Square Distribution↗
New information on fecal occult blood testing.
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Comment↗
Registered nurse-administered propofol sedation for upper endoscopy and colonoscopy: Why? When? How?
Propofol for sedation during gastrointestinal endoscopic procedures has been associated with improved patient satisfaction relative to combinations of meperidine and midazolam. Delivery of propofol by registered nurses has been shown to be more cost-effective than administration by anesthesiologists or nurse anesthetists. Here, the authors review their experience with nurse-administered propofol sedation (NAPS) at their institutions (a hospital endoscopy unit in a tertiary medical center and an ambulatory surgery center). Endoscopic procedures for which NAPS is (or is not) recommended are listed, and a profile of patients for whom NAPS is contraindicated is given. Steps toward the development of programs and acquisition of training in NAPS are recommended; these include determining what state, local, and institutional laws apply to propofol administration; developing a written protocol; and instituting a training program that proceeds from observation to supervised administration to independent administration of propofol, with appropriate monitoring of safety records. Experience with NAPS using bolus titration (dosage, timing, coadministration with other agents) is detailed, and proper patient monitoring is discussed. NAPS is in its infancy, but this method of sedation shows considerable promise for improving patient satisfaction with, and thereby the reputation of, endoscopic procedures.
Colonoscopy↗
Postpolypectomy and post-cancer resection surveillance.
Recent guidelines on postpolypectomy surveillance have focused on identifying patients with adenomas who are at high risk for development of significant neoplasms (cancer or "advanced adenoma") after clearing colonoscopy and should undergo frequent follow-up examinations and those at low risk who require infrequent follow-up examinations. This article reviews the guideline recommendations from the American College of Gastroenterology, American Gastroenterological Association consortium, and the American Cancer Society, and discusses the rationale for the recommended intervals of colonoscopic examinations in low and high-risk postpolypectomy patients. When colorectal cancer is identified, the initial colonoscopic goal in the peri-operative period is to clear the colon of synchronous neoplasms. After this is accomplished, the goal shifts to performance of colonoscopy at intervals that are appropriate for prevention and early detection of second cancers. These intervals often approximate those used in postpolypectomy surveillance. An exception to this approach is patients with rectal cancer operated by traditional blunt dissection techniques, for which there is a rationale for interval flexible sigmoidoscopy and/or rectal ultrasound to look for local recurrences.
Adenocarcinoma↗
Making sense of a family history of polyps.
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Journal Article↗