Effect of supplemental oxygen on cardiopulmonary changes during gastrointestinal endoscopy.

This prospective study evaluated supplemental oxygen as an effective means of preventing hypoxemia and electrocardiographic changes in sedated patients undergoing endoscopic procedures. Ninety-five patients with documented ischemic heart disease and 106 patients without heart or lung disease were studied. Patients within each group received either supplemental oxygen (2 L/minute) via nasal cannula or room air. Hypoxemia (oxygen saturation below 90%) and ST-segment deviations occurred in cardiac and control groups. The combination of midazolam and meperidine significantly increased the risk for hypoxemia as compared to midazolam alone (44% versus 8%). Supplemental oxygen significantly decreased, but did not entirely prevent, hypoxemia in cardiac and control groups. The incidence of ST-segment deviation in cardiac patients who were hypoxic was significantly lower in the group receiving oxygen (p = .0015). Supplemental oxygen did not affect the incidence of arrhythmias. Prophylactic supplemental oxygen should be administered to patients with ischemic heart disease who undergo conscious sedation for upper and lower gastrointestinal endoscopic procedures.

Patents for genetically modified animals.

Should genetically engineered animals be patented? This issue has been one of the most contentious as lawmakers have grappled with how best to protect intellectual property. Since the 1980 case of Diamond v. Chakrabarty, in which the U.S. Supreme Court ruled that a living microorganism is patentable, the U.S. Patent and Trademark Office has determined that plants and nonhuman animals can be patented. These policy decisions have led to congressional debate on whether animals should be patentable subject matter. Patenting of living organisms is unique for three reasons: the invention itself is alive; the invention in some instances can reproduce itself; and the invention sometimes cannot be adequately described for patent specification purposes, leading to the need for deposit of the invention for patent purposes.

Crohn disease of the small intestine: accuracy and relevance of enteroclysis.

The accuracy and clinical relevance of enteroclysis in the evaluation of 138 patients referred for enteroclysis for suspected Crohn disease of the small intestine are reported. The original prospective interpretations of enteroclysis results were assessed after a clinical follow-up period of 2 or more years. With all patients considered, enteroclysis had a sensitivity, specificity, and accuracy of 100%, 98.3%, and 99.3%, respectively, with only one false-positive diagnosis and no false-negative diagnoses. Thirty-one percent (n = 43) of the patients had lesions of early Crohn disease. All patients who required surgery (n = 23) had advanced lesions of the disease, according to enteroclysis criteria. Clinical evidence of Crohn disease did not develop in the 58 patients in whom enteroclysis revealed no abnormality. There were no complications related to the procedure. It is concluded that enteroclysis is an accurate method for diagnosis and exclusion of Crohn disease of the small intestine and provides detailed structural information relevant to appropriate management of the disease.

Frequency of abnormal sphincter of Oddi manometry compared with the clinical suspicion of sphincter of Oddi dysfunction.

Patients with pancreaticobiliary pain or idiopathic pancreatitis have been classified as having definitive (type I), presumptive (type II), or possible (type III) sphincter of Oddi dysfunction (SOD) based on clinical, laboratory, and ERCP data. This study was undertaken to determine the frequency of abnormal sphincter of Oddi manometry (SOM) when patients are classified by this system. Two hundred and thirteen patients with pancreaticobiliary pain were evaluated clinically; SOM, ERCP, and ductal contrast drainage time tests were performed. For biliary types I, II, and III, the frequency of abnormal SOM was 85.7%, 55.1%, and 28.1%, respectively. Similarly, for pancreatic types I, II, and III, an elevated basal sphincter pressure occurred in 92.3%, 58.2%, and 35.1%, respectively. When patients with an abnormal basal sphincter pressure were characterized by the magnitude of the elevation, the manometric profiles were similar for types I, II, and III. These data suggest that elevated sphincter pressure occurs more frequently in type III patients than previously reported, and supports consideration of SOM when evaluating and treating type II and type III patients.

Minor papilla cannulation and dorsal ductography in pancreas divisum.

Until recently, pancreas divisum represented a major technical barrier to a complete evaluation of pancreatic ductal anatomy. Technical refinements have now made it possible to achieve minor papilla cannulation and dorsal ductography in more than 90% of attempts. In 120 consecutive dorsal ductograms, structural pathology was demonstrated in 36 subjects (30%): chronic pancreatitis in 23, pancreatic stones in 10, pseudocyst(s) in 4, ductal "cut-off" in 7, pancreatic cancer in 3, and partial agenesis in 1 (some patients had more than one finding). For patients in whom alcohol abuse was excluded, ductal pathology was present in 25%. Abnormal ventral ductograms were present in only 8% of cases, demonstrating that dorsal ductography has an appreciable additional diagnostic yield. When the clinical situation indicates the need for pancreatography, minor papilla cannulation should be performed if major papilla cannulation fails or reveals only the ventral pancreatogram of pancreas divisum.

Performing screening flexible sigmoidoscopy using colonoscopes: experience in 500 subjects.

There is still controversy regarding the optimal length of flexible sigmoidoscopes. We performed screening distal colon examinations using 168-cm colonoscopes in 500 asymptomatic subjects who were unsedated and had sigmoidoscopy cleansing preparation. The mean depth of penetration was 66 cm and was similar in persons in whom the examination was discontinued because of poor preparation versus those with discomfort. Polyps were detected in 87 patients, but only 5 subjects had polyps detected above 60 cm. We conclude that in a group of unsedated subjects scheduled for flexible sigmoidoscopy after a sigmoidoscopy prep, the use of instruments longer than 60 cm gives very little additional yield.

Oxygen desaturation is common and clinically underappreciated during elective endoscopic procedures.

This study compared how often oxygen desaturation occurred during conscious sedation for upper and lower procedures, the frequency and extent of desaturation occurring after sedation with diazepam plus meperidine to that occurring after midazolam plus meperidine, and the relationship between age or type of procedure (upper versus lower) with oxygen desaturation to less than 90%. Two-hundred and thirty-six consecutive patients undergoing elective upper or lower endoscopic procedures under conscious sedation had oxygen saturation measured by pulse oximeter before sedation, following sedation but prior to the procedure, and while sedated and undergoing the procedure. Forty-five percent of the subjects desaturated to less than 90% without demonstrating any clinical signs of distress, including 40% of those undergoing upper procedures and 54% of those undergoing lower procedures. Neither the age of the patient, the drugs used, drug doses used, nor the type of procedure accurately predicted which patients would desaturate to less than 90%. Potentially significant oxygen desaturation cannot be reliably predicted by clinical criteria. Pulse oximetry is far more sensitive than standard clinical monitoring practices in detecting oxygen desaturation.

1989 A/S/G/E survey of endoscopic sedation and monitoring practices.

Monitoring practices for conscious sedation during gastrointestinal endoscopic procedures are not standardized. A questionnaire was sent to 509 randomly selected A/S/G/E members to define current national sedation and monitoring practices. Responses were returned by 290 members (57%) from 45 states. The average respondent was between 35 and 54 years of age and had 12.4 years of endoscopic experience. Excluding flexible sigmoidoscopy, most patients were routinely sedated for endoscopic procedures. Meperidine (87%), midazolam (73%), diazepam (49%), and naloxone (30%) were the drugs most often used during conscious sedation. When a minor tranquilizer was used, midazolam (62%) was used more often than diazepam (38%). Cardiopulmonary sedation-related complications had a low annual occurrence rate of less than 0.5%. Most endoscopists monitor vital signs before and after procedures (greater than 90%) but less often during procedures (77%). Pulse oximeters and electrocardiographic monitoring were used by 65% and 55% of endoscopists, respectively. Electronic monitoring was used more often for patients undergoing endoscopy in hospitals (99.5%) than in private offices (27%). Fifty-four percent of respondents reported that they had a written endoscopy unit policy concerning conscious sedation. Among endoscopists and gastrointestinal assistants, basic life-support certification was common (76% and 77%, respectively), but advanced cardiac life-support was far less common (30% and 18%). This survey found the use of intravenous conscious sedation for gastrointestinal endoscopic procedures to be safe. Monitoring of patients with vital signs is used regularly; moreover, the majority of endoscopists now also employ electronic monitoring equipment.

Cholecystocolonic fistula: malabsorptive consequences of lost bile acids.

A patient with the painless onset of a cholecystocolonic fistula associated with virtually complete common bile duct obstruction due to stones provided a unique opportunity to assess the consequences of prolonged bile acid depletion on the digestion and absorption of nutrients. Over 2 years, the patient insidiously developed steatorrhea, osteomalacia with an atraumatic pelvic fracture, and congestive heart failure complicated by polymorphic ventricular tachycardia (torsade de pointes) all of which could be attributed to malabsorption of fat and fat-soluble vitamins.

Flexible sigmoidoscopy plus air contrast barium enema versus colonoscopy for suspected lower gastrointestinal bleeding.

A randomized, controlled trial was performed to compare the diagnostic yields and cost-effectiveness of two strategies for the evaluation of nonemergent lower gastrointestinal bleeding. Three hundred eighty patients aged greater than or equal to 40 yr were randomized to undergo initial flexible sigmoidoscopy plus air contrast barium enema or colonoscopy; 332 completed the initial studies. Initial colonoscopy detected more cases of polyps less than 9 mm in size, adenomas, and arteriovenous malformations but fewer cases of diverticulosis. No significant difference was found between strategies in the number of patients detected with cancers or polyps greater than or equal to 9 mm in size. In both strategies, cancers were more common in subjects aged greater than or equal to 55 yr (8% overall) than in those aged less than 55 yr (1%). Among patients aged less than 55 yr with suspected lower gastrointestinal bleeding, initial flexible sigmoidoscopy plus air contrast barium enema is a more cost-effective strategy for the detection of colonic neoplasms than initial colonoscopy. However, initial colonoscopy is more cost effective for those aged greater than or equal to 55 yr.

Comparison of three nonsurgical treatments for bleeding esophageal varices.

Ninety-seven patients with recent or active variceal bleeding were randomly assigned to oral propranolol, endoscopic sclerotherapy plus oral propranolol, or transhepatic sclerotherapy plus oral propranolol. The effects of treatment on the number of units transfused, rebleeding of any magnitude, major rebleeding, and death were assessed in these patients, 82% of whom were alcoholic and 81% Child's Class C. After a minimum follow-up interval of 2 yr (range, 27-65 mo), major rebleeding rates were 65% for propranolol alone, 45% for endoscopic sclerotherapy plus propranolol, and 60% for transhepatic sclerotherapy plus propranolol. The corresponding death rates were 81% for propranolol alone, 55% for endoscopic sclerotherapy plus propranolol, and 66% for transhepatic sclerotherapy plus propranolol (p = 0.03). Thirty-three patients (34%) never received propranolol; 8 due to medical contraindications and 25 because they died or bled enough to meet the definition of treatment failure within 3 or 4 days of randomizations (no significant differences among treatment groups). Patients assigned to propranolol alone bled sooner, bled more units, and had a higher mortality rate than patients treated by endoscopic sclerotherapy plus propranolol. Patients treated with transhepatic sclerotherapy plus propranolol had intermediate results. Propranolol alone is inadequate treatment for esophageal variceal bleeding in patients with advanced liver disease.

Oral medications for upper gastrointestinal endoscopy using a small diameter endoscope.

We carried out a double-blinded, randomized prospective study to compare patient tolerance of small diameter endoscopes using limited potency oral premedication to complement topical anesthesia. Patients randomly received either oral placebo, diphenhydramine (100 mg), acetaminophen (1000 mg), or both drugs 30 to 60 min prior to endoscopy. All patients received topical Cetacaine and underwent upper endoscopy with the Olympus XP10 7.9-mm fiberscope. The combination of acetaminophen (1000 mg) and diphenhydramine (100 mg) significantly improved tolerance over topical anesthetic alone. Obvious sedation from the medications was infrequent. Gag response after a topical anesthesia was a significant predictor of patient tolerance. We conclude that small diameter endoscopes are well tolerated for diagnostic upper endoscopy. Oral premedications additionally improve tolerance slightly.

Endoscopic placement of collagen at the lower esophageal sphincter to inhibit gastroesophageal reflux: a pilot study of 10 medically intractable patients.

Ten highly symptomatic and medically refractory refluxing patients were treated with a new endoscopic technique to decrease gastroesophageal reflux. Cross-linked bovine dermal collagen was injected beneath the mucosa in the area of the lower esophageal sphincter through a 23 gauge needle-tipped catheter. A mean volume of 85 ml of implant was injected in 0.5- to 4-ml increments over 3 to 10 injection sessions. All patients developed objective evidence of decreased reflux by one or more parameters. Nine out of 10 patients had decreased symptoms, and 8 of 9 patients had an increase in lower esophageal pressure after implant injection. Endoscopic implant treatment resulted in statistically significant improvement in symptom scores (p less than 0.001), the standard acid reflux test (p = 0.009), and lower esophageal sphincter pressures (p = 0.002), but not in the endoscopic appearance of the esophagus (p = 0.131). Subjective and objective improvements in reflux parameters generally lasted 6 to 9 months with return toward pretreatment status by 12 months. Antibodies to bovine collagen developed in 5 of 10 subjects with no clinical sequelae and no apparent reactivity with human collagen. The technique is not difficult to perform and is well tolerated by patients, and the results indicate the potential for more general use with a more suitable implant material.

Effect of instrument diameter on the depth of penetration of fiberoptic sigmoidoscopes.

Newer fiberoptic sigmoidoscopes tend to have smaller diameter insertion shafts than older models. The extent to which this diameter affects how deeply an instrument can be inserted into the colon and the frequency with which sigmoidoscopes of different diameters could reach more proximal areas of the colon was evaluated. Instrument diameter did not influence the length of the sigmoidoscope shaft that could be introduced into the patient. However, when fully inserted to 60 cm, the 12-mm diameter sigmoidoscopes viewed significantly less of the sigmoid and descending colon than did the 16-mm diameter sigmoidoscopes. This lesser degree of anatomic depth of penetration has direct implications for the diagnostic capabilities of smaller diameter instruments.

The yield of routine duodenal aspiration for Giardia lamblia during esophagogastroduodenoscopy.

Giardia lamblia, the most common intestinal parasite in the United States, may present with nonspecific gastrointestinal symptoms when the infection is chronic. In order to determine how frequently the parasite could be detected in patients undergoing endoscopy for standard indications, duodenal aspirates were collected from 144 patients. Despite G. lamblia being endemic in the state (and therefore readily recognized in our laboratory), there was only one positive aspirate in the 144 specimens collected (0.7%) at this midwestern, tertiary care facility servicing a primarily middle class population. In the population sampled, routine duodenal aspiration for G. lamblia in patients not clinically suspected of having this parasitic infection is of very low yield.