PubMed Health⌕ Search

Biomedical subjects

John J Vargo

Publications and source records attributed to John J Vargo.

At least 19 recordsLinked to original sources

Propofol: a gastroenterologist's perspective.

The use of propofol for GI endoscopy has left the realm of experimentation and is now a viable alternative to standard sedation and analgesia. In the hands of appropriately trained gastroenterologists and registered nurses, propofol has been shown to be superior to standard sedation and analgesia in terms of patient satisfaction and comfort and shorter recovery parameters. Comparative studies have found it to be as safe as the regimens that are used for standard sedation and analgesia. Its narrow therapeutic window demands that specially trained personnel who are not directly involved in the endoscopic procedure administer it. Cost-effectiveness data suggest that propofol is superior to conventional sedation and analgesia, even with the use of added personnel.The importance of pre-procedural assessment and appropriate monitoring cannot be overemphasized. The endoscopist must have a thorough knowledge of the pharmacology of the agents used for sedation and the training necessary to recognize and manage over sedation. Numerous regulatory groups are carefully scrutinizing the practice of sedation and analgesia. It seems that ventilatory monitoring will be required for at least a subset of patients. Although hypercapnia and apnea can be reliably measured, the most important questions to be answered are if such monitoring affects patient outcomes and which patients are at risk for apnea and alveolar hypoventilation.

Clinical Trials as Topic↗

Electrolyte composition of endoscopically collected duodenal drainage fluid after synthetic porcine secretin stimulation in healthy subjects.

BACKGROUND: Traditional pancreatic function tests are sensitive for the diagnosis of pancreatic exocrine insufficiency but are cumbersome and difficult to perform. A sedationless endoscopic pancreatic function test that has the potential for wide clinical application was developed by us, but data on the results of this method in healthy subjects are lacking. This study analyzed endoscopically collected duodenal fluid from healthy subjects after synthetic porcine secretin stimulation. METHODS: Healthy subjects underwent the sedationless endoscopic pancreatic function test. After secretin stimulation, duodenal aspirates were obtained every 5 minutes for 1 hour. The collected fluid was analyzed for electrolyte concentrations. RESULTS: Sixteen healthy subjects (8 women, 8 men; median age 34.5 years) underwent the endoscopic pancreatic function test. The concentrations of the sodium ([Na+]) and potassium ([K+]) cations remained constant, similar to normal concentrations in plasma (median [Na+], 155 mEq/L; median [K+], 4.3 mEq/L). The concentrations of the bicarbonate ([HCO 3 - ]) and chloride anions increased and decreased, respectively, in an inverse and reciprocal manner, similar to the previously characterized "secretory curve." The median peak [HCO 3 - ] was 108 mEq/L IQR: 99-110). By the 20-minute collection, the [HCO 3 - ] was greater than 80 mEq/L for 94% (15/16) of subjects, the historic cut point for [HCO 3 - ] in studies based on traditional methods of pancreatic function testing. CONCLUSIONS: Endoscopic collection of pancreatic fluid reproduces the anion-cation secretory curve described by prior studies of pancreatic secretory physiology based on traditional collection methods.

Adult↗

Analysis of pancreatic elastase-1 concentrations in duodenal aspirates from healthy subjects and patients with chronic pancreatitis.

Fecal pancreatic elastase 1 (PE-1) has been advocated as a noninvasive marker of pancreatic function and allows detection of moderate and severe exocrine insufficiency. Few studies have evaluated the utility of measuring PE-1 in duodenal fluid for the diagnosis of pancreatic insufficiency. Our purpose was (1) to determine the feasibility of measuring PE-1 concentrations in duodenal aspirates obtained through our endoscopic pancreatic function test (ePFT) in healthy subjects and patients with chronic pancreatitis (CP) and (2) to determine correlations between duodenal PE-1 concentrations and bicarbonate and lipase concentrations in duodenal fluid. Healthy subjects (HS) and CP patients underwent an ePFT with CCK or secretin. CP was defined as endoscopic retrograde pancreatography (ERP) Cambridge class III-IV, endoscopic ultrasound (EUS) score >5, or presence of pancreatic calcifications on CT scan. Duodenal fluid PE-1, lipase, and bicarbonate concentrations were measured in each study group. Duodenal lipase and bicarbonate concentrations were measured using an autoanalyzer (Roche Diagnostics, Indianapolis, IN). PE-1 was measured using an ELISA (Genova Diagnostics, Asheville, NC). Ten HS and 10 CP patients were studied. In the CCK test the median peak lipase for HS and CP was 1605 and 113 IU/L, respectively (P < 0.008). In the secretin test the median peak bicarbonate for HS and CP was 102 and 40 mEq/L, respectively (p < 0.008). Median PE-1 concentrations for HS and CP were 317 and 63 microg/ml, respectively, after CCK stimulation (p = 0.046) and 87 and 17 microg/ml, respectively, after secretin stimulation (p = 0.033). Statistically significant correlations were found between [PE-1] and peak [lipase] (r = 0.83, P < 0.001), as well as [PE-1] and peak [HCO3(3)-] (r = 0.65, P = 0.037). Conclusions are as follows: (1) PE-1 concentrations can be measured from duodenal fluid obtained by endoscopic aspiration. (2) Duodenal fluid PE-1 concentrations are decreased in CP compared to HS. (3) Duodenal fluid [PE-1] has an excellent correlation with [lipase] and therefore is a marker of acinar cell function. (4) Secretin-stimulated endoscopic function testing with measurement of bicarbonate and PE-1 may provide a simultaneous assessment of both ductal cell and acinar cell function.

Adult↗

An endoscopic pancreatic function test with cholecystokinin-octapeptide for the diagnosis of chronic pancreatitis.

BACKGROUND & AIMS: Current pancreatic function tests are cumbersome and unavailable to the clinical gastroenterologist. We have developed a function test that can be modified to a purely endoscopic collection method (ePFT). The aim of this study was to compare the endoscopic and traditional Dreiling tube collection methods. METHODS: Two separate groups of healthy subjects and patients with chronic pancreatitis underwent pancreatic function testing. One group underwent the endoscopic collection method (ePFT). Intravenous cholecystokinin (CCK 40 ng x kg(-1) x h(-1)) was started in preprocedure area. Duodenal fluid was collected with upper endoscope during endoscopy at 30, 40, 50, and 60 minutes during infusion. Another group underwent the traditional Dreiling collection method. Intravenous CCK was started in postprocedure area after endoscopic tube placement. Duodenal fluid was collected at 0, 20, 40, 60, and 80 minutes during infusion. Lipase concentration was determined (IU/L) on laboratory autoanalyzer. RESULTS: Seventy-three patients were studied. Thirty-four underwent endoscopic collection and 39 underwent Dreiling collection. The mean peak lipase concentrations (+/- standard deviation) for healthy subjects and patients with chronic pancreatitis in the endoscopic collection method group were 1612500 +/- 556152 IU/L and 369594 +/- 281624 IU/L, respectively (P < 0.001). The mean peak lipase concentrations (+/- standard deviation) for healthy subjects and patients with chronic pancreatitis in the Dreiling tube collection method group were 1670324 +/- 786731 IU/L and 478956 +/- 406061 IU/L, respectively (P < 0.001). There was no statistical difference between collection methods at distinguishing healthy subjects and patients with chronic pancreatitis. Receiver operating characteristic curves (ROC) for the endoscopic and Dreiling collection methods were 0.993 (standard error of mean, 0.009) and 0.921 (standard error of mean, 0.041). A lipase concentration cut point of 810600 IU/L distinguishes healthy subjects from patients with chronic pancreatitis with a sensitivity and specificity of 92% and 95%, respectively. The ePFT was safe, short in duration, minimized costs (US dollars 1890 vs. US dollars 2659), required small amounts of fluid for analysis (1-3 mL), and eliminated radiation exposure. CONCLUSIONS: Analysis of timed endoscopic aspirations of pancreatic juice after hormonal stimulation can distinguish healthy subjects from patients with chronic pancreatitis. This new endoscopic collection method (ePFT) is less cumbersome and more time efficient, when compared to traditional collection methods. The ePFT broadens the availability of function testing to the practicing clinical gastroenterologist.

Adult↗

An endoscopic pancreatic function test with synthetic porcine secretin for the evaluation of chronic abdominal pain and suspected chronic pancreatitis.

BACKGROUND: Pancreatic function tests are the most reliable methods for the diagnosis or exclusion of chronic pancreatitis in patients without obvious radiologic changes, but they are cumbersome, time consuming, and unavailable in clinical practice. Synthetic porcine secretin, a 27 amino acid peptide identical to the biologic form, is available for exocrine function testing. This study examined the utility of a simple, newly developed, purely endoscopic pancreatic function test with synthetic porcine secretin. METHODS: Three groups of patients were studied: patients with chronic abdominal pain with and without risk factors for chronic pancreatitis, and patients with advanced chronic pancreatitis. All patients with abdominal pain had "pancreatic type" pain for greater than 6 months and negative radiographic imaging studies. All patients with chronic pancreatitis had advanced disease based on retrograde pancreatography and/or CT findings. Participants underwent the following protocol: (1) standard endoscopy to the descending duodenum with the patient under conscious sedation; (2) intravenous administration of secretin (0.2 microgram/kg); (3) endoscopic duodenal fluid collection at 0, 15, 30, 45, and 60 minutes after secretin injection; and (4) fluid analysis for bicarbonate concentration. RESULTS: Eighteen patients were studied (5 abdominal pain without risk factors, 7 abdominal pain with risk factors, and 6 advanced chronic pancreatitis). Median peak (interquartile range) bicarbonate concentrations in meq/L for each group were, respectively, 87 (6, range 84-108), 72 (10, range 68-90), and 35 (27, range 18-88). Median peak bicarbonate concentration values for the 3 groups are significantly different (p = 0.010; Kruskal-Wallis test). Bicarbonate secretion in patients with chronic pancreatitis was markedly reduced compared with that in patients with abdominal pain without risk factors (p = 0.038; the Fisher exact test). The secretory function curve for patients with abdominal pain with risk factors was markedly abnormal, resembling the attenuated secretory curve seen in patients with chronic pancreatitis. The test was safe and well tolerated. CONCLUSIONS: A simple endoscopic pancreatic function test with synthetic porcine secretin appears to distinguish patients with known chronic pancreatitis from those with chronic abdominal pain without chronic pancreatitis. This simple, practical endoscopic test can be performed during upper endoscopy and may decrease the need for invasive procedures in patients with abdominal pain and normal radiographic imaging studies.

Abdominal Pain↗

Role of clinically determined depth of tumor invasion in the treatment of esophageal carcinoma.

OBJECTIVE: We sought to evaluate the effectiveness of clinical staging of depth of tumor invasion (cT), the relationship of cT to survival, the benefits of downstaging cT, and the role of cT in treatment decisions. METHODS: The accuracy of determining T by means of endoscopic ultrasonography and the relationship of cT to survival were assessed in 209 patients undergoing esophagectomy alone for esophageal carcinoma. The benefit of downstaging cT was assessed in 128 patients undergoing induction therapy and esophagectomy. The role of cT in treatment decisions was determined by integrating these results with the results of previous work. RESULTS: Compared with pathologic T (pT), cT was 87% accurate, 82% sensitive, 91% specific, 89% positively predictive, and 86% negatively predictive of tumors confined to (< or =T2) or invading beyond (>T2) the esophageal wall. In cN0, increasing cT was predictive of progressively poorer survival. For each category of pT N0, cT accurately predicted survival, except for pT3, which was underestimated (P <.0001). In cN0, downstaging by induction therapy was beneficial only if tumors invaded beyond the wall (> or =cT3, P =.0003). In cN1, it was beneficial only when downstaging was synchronous in cT3/T4 (P <.001). CONCLUSIONS: cT should be the principal determinant of treatment in cN0. In cN0, if endoscopic ultrasonography identifies tumors of greater than cT2, multimodality therapy should be considered. However, only when cT3/T4 tumors are downstaged to pT2 or less will patients benefit, but their survival will not equal that of patients with tumors of cT2 or less having esophagectomy alone. If endoscopic ultrasonography identifies tumors of cT2 or less, esophagectomy alone should be used because induction therapy might adversely affect survival.

Adenocarcinoma↗

Guideline on the management of anticoagulation and antiplatelet therapy for endoscopic procedures.

This is one of a series of statements discussing the practice of gastrointestinal endoscopy in common clinical situations. It is intended to aid endoscopists in determining the appropriate use of endoscopic procedures in conjunction with anticoagulation and/or antiplatelet therapy. Guidelines for the appropriate practice of endoscopy are based on critical review of the available data and expert consensus. Controlled clinical studies would be beneficial to clarify some aspects of this statement and revision might be necessary as new data appear. Clinical consideration may justify a course of action at variance from these specific recommendations.

Anticoagulants↗

Methods of granting hospital privileges to perform gastrointestinal endoscopy.

This is one of a series of statements discussing the utilization of gastrointestinal endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy prepared this text. In preparing this guideline, a MEDLINE literature search was performed, and additional references were obtained from the bibliographies of the identified articles and from recommendations of expert consultants. When little or no data exist from well-designed prospective trials, emphasis is given to results from large series and reports from recognized experts. Guidelines for appropriate utilization of endoscopy are based on a critical review of the available data and expert consensus. Further controlled clinical studies are needed to clarify aspects of this statement, and revision may be necessary as new data appear. Clinical consideration may justify a course of action at variance to these recommendations.

Credentialing↗

Complications of upper GI endoscopy.

This is one of a series of statements discussing the utilization of gastrointestinal endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy prepared this text. In preparing this guideline, a MEDLINE literature search was performed, and additional references were obtained from the bibliographies of the identified articles and from recommendations of expert consultants. When little or no data exist from well-designed prospective trials, emphasis is given to results from large series and reports from recognized experts. Guidelines for appropriate utilization of endoscopy are based on a critical review of the available data and expert consensus. Further controlled clinical studies are needed to clarify aspects of this statement, and revision may be necessary as new data appear. Clinical consideration may justify a course of action at variance to these recommendations.

Endoscopy, Gastrointestinal↗

Role of endoscopy in enteral feeding.

This is one of a series of statements discussing the utilization of gastrointestinal endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy prepared this text. A previous guideline related to this topic (ASGE Publication No. 1017, Gastrointest Endosc 1998;48:699-701). Since that time, new information has become available that requires an update of this statement and its recommendations. In preparing this update, a MEDLINE literature search was performed, and additional references were obtained from the bibliographies of the identified articles and from the recommendations of expert consultants. When inadequate data existed from well-designed prospective trials, emphasis was given to results from large series and reports from recognized experts. Guidelines for appropriate utilization of endoscopy are based on a critical review of the available data and expert consensus. Controlled clinical studies are needed to clarify aspects of this statement, and revision may be necessary as new data appear. Clinical consideration may justify a course of action at variance from these recommendations.

Endoscopy, Gastrointestinal↗

Guideline for the management of ingested foreign bodies.

This is one of a series of statements discussing the utilization of gastrointestinal endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy prepared this text. In preparing this guideline, a MEDLINE literature search was performed, and additional references were obtained from the bibliographies of the identified articles and from recommendations of expert consultants. When little or no data exist from well-designed prospective trials, emphasis is given to results from large series and reports from recognized experts. Guidelines for appropriate utilization of endoscopy are based on a critical review of the available data and expert consensus. Further controlled clinical studies are needed to clarify aspects of this statement, and revision may be necessary as new data appear. Clinical consideration may justify a course of action at variance to these recommendations.

Digestive System↗