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Douglas B Nelson

Publications and source records attributed to Douglas B Nelson.

29 records · Page 2Linked to original sources
PubMed2003

Multi-society guideline for reprocessing flexible gastrointestinal endoscopes. Society for Healthcare Epidemiology of America.

Flexible gastrointestinal endoscopy is a valuable diagnostic and therapeutic tool for the care of patients with gastrointestinal and pancreaticobiliary disorders. Compliance with accepted guidelines for the reprocessing of gastrointestinal endoscopes between patients is critical to the safety and success of their use. When these guidelines are followed, pathogen transmission can be effectively prevented. Increased efforts and resources should be directed to improve compliance with these guidelines. Further research in the area of gastrointestinal endoscope reprocessing should be encouraged. The organizations that endorsed this guideline are committed to assisting the FDA and manufacturers in addressing critical infection control issues in gastrointestinal device reprocessing.

Cross Infection↗
PubMed2003

Acute GI bleeding in the setting of supratherapeutic international normalized ratio in patients taking warfarin: endoscopic diagnosis, clinical management, and outcomes.

BACKGROUND: Acute GI bleeding is a life-threatening complication of warfarin therapy. Acute GI bleeding in patients with an international normalized ratio of 4.0 or greater (supratherapeutic) is often attributed to trivial mucosal lesions. The aim of the study was to determine the frequency of potentially significant lesions that would warrant endoscopy in this setting. METHODS: A retrospective review was conducted of patients treated with warfarin who were admitted to a single Veterans Affairs hospital from 1996 to 2000 with acute GI bleeding. Endoscopic findings, clinical management, and outcomes are reviewed for patients with a supratherapeutic international normalized ratio (>or=4.0) and compared with patients with an international normalized ratio in the therapeutic range (2.0-3.9). RESULTS: Fifty-five patients with an international normalized ratio of 4.0 or greater (mean 8.4 [3.9]) and 43 patients with an international normalized ratio between 2.0 and 3.9 (mean 2.9 [0.6]) were hospitalized with acute GI bleeding. Thirty-seven patients (67%) with a supratherapeutic international normalized ratio and GI bleeding underwent upper endoscopy. Of these, 81.1% had positive findings, 18.9% had peptic ulcer disease, and 7.2% required endoscopic treatment. Thirty-eight percent of the patients with a supratherapeutic international normalized ratio underwent lower endoscopy; of these, 57.1% had abnormal findings and 9.5% required endoscopic treatment. Four patients (7.3%) in the supratherapeutic international normalized ratio group died during the index hospitalization. When patients with GI bleeding and a therapeutic international normalized ratio were compared with those with a supratherapeutic international normalized ratio, there were no significant differences between the two groups with regard to days of hospitalization, units of blood transfused, frequency of recurrent bleeding, need for surgery, or in-hospital deaths. CONCLUSIONS: The high frequency of clinically significant lesions in patients taking warfarin with an international normalized ratio in the supratherapeutic range and acute GI bleeding supports a role for endoscopic evaluation.

Acute Disease↗
PubMed2002

Mucosal plasma cell repertoire during HIV-1 infection.

Impaired development of local Ab responses may predispose HIV-1-infected patients to an increased rate, severity, and duration of mucosal infections. We characterized the repertoire of Ig-producing cells in the intestinal effector compartment (the lamina propria) of HIV-1-infected (n = 29) and seronegative control (n = 27) subjects. The density of Ig-producing cells per area was similar in both groups. However, the proportions of IgA-producing cells were lower in both the duodenum and colon from HIV-1-infected patients compared with those of control subjects (p < 0.05), with compensatory increases in IgG-producing cells in the colon and IgM-producing cells in the duodenum. Similarly, among Abs in the lumen the proportions of IgA were also decreased and the proportions of IgG were increased among HIV-1-infected patients. On a molecular level, V(H) gene repertoire analyses by RT-PCR revealed comparable proportions of the V(H)3 family among duodenal IgA transcripts (50-53%) from both groups. V(H)3 expression was decreased only for IgM among patients with advanced HIV-1 disease (n = 6) compared with that of control subjects (n = 8) (48 +/- 8 vs 62 +/- 13%; p < 0.01). Moreover, the frequencies of individual IgM and IgA V(H)3 genes were comparable in each group, including rates of putative HIV-1 gp120-binding V(H)3 genes (V3-23, V3-30, V3-30/3-30.5). We conclude that, despite a decrement in local IgA producing cells, the density and molecular V(H) repertoire of mucosal plasma cells are relatively intact among patients with HIV-1 infection. These data suggest that HIV-1-infected patients use functional regulatory mechanisms to provide sufficient V(H) diversity and effective induction and differentiation of mucosal B cells.

Adult↗
PubMed2002

New technology in the endoscopy center.

The boundaries of endoscopy will continue to expand. Imaging modalities, such as high-resolution and high magnification endoscopy, tissue spectroscopy, optical coherence tomography, and wireless endoscopy, will continue to evolve. New therapeutic modalities, such as endoscopic antireflux procedures, are making endoscopic surgery a reality. In the increasingly restrictive reimbursement environment, however, it is critical to establish the cost-effectiveness of these new technologies to integrate them into daily practice.

Ambulatory Care Facilities↗
PubMed2002

"Tannenbaum" Teflon stents versus traditional polyethylene stents for treatment of malignant biliary stricture.

BACKGROUND: Premature stent clogging is the major limitation with plastic stents used in the treatment of malignant biliary structures. A pilot study suggested improved duration of patency of the Tannenbaum stent compared with polyethylene stents. The aim of this prospective, multicenter randomized trial was to compare the Tannenbaum Teflon stent with a conventional polyethylene endoprosthesis (Cotton-Leung biliary stent set) for the treatment of malignant biliary strictures. METHODS: Patients over age 18 years with symptoms caused by nonhilar malignant biliary strictures were enrolled. Patients were randomized to receive a 10F Tannenbaum or polyethylene stent after a guidewire was passed beyond the stricture. One hundred six patients (mean age 72 years and 71 years, respectively) were enrolled (54 Tannenbaum, mean age 72 years; 52 polyethylene, mean age 71 years). RESULTS: Tannenbaum and polyethylene stent placement was successful in, respectively, 100% and 96% of procedures without complications. The mean (SD) 90-day stent patency of the Tannenbaum stent was 67% (7%) compared with 73% (7%) for the polyethylene stents. CONCLUSIONS: The present study demonstrated no difference in ease of implantation or stent patency between Tannenbaum and polyethylene stents.

Aged↗
PubMed2002

Procedural success and complications of large-scale screening colonoscopy.

BACKGROUND: Indirect evidence and modeling analyses suggest that colonoscopy may be the most cost-effective way to screen the average-risk population for colorectal neoplasia. However, the success and safety of primary colonoscopic screening has not been prospectively evaluated in a multicenter trial. METHODS: Asymptomatic subjects age 50 to 75 years who had not undergone examination of the colon within 10 years were recruited from the general medicine clinics of 13 Department of Veterans Affairs Medical Centers. Eligible patients underwent colonoscopy by study coinvestigators, at which time all polyps were measured, photographed, and removed. Patients were contacted at 24 hours and 1 week to track procedure-related complications. RESULTS: Primary screening colonoscopy was performed in a cohort of 3196 asymptomatic subjects. A "good" preparation was reported in 81% of patients, and colonoscopy to the cecum was successful in 97.2% of cases. Mean insertion time to the cecum and total procedure times were 10.5 (8.7) and 30.6 (19.1) minutes, respectively. No preprocedural patient characteristics were identified that were predictive of an incomplete procedure. At least one polyp was resected in 1672 patients. There was no perforation and no death attributed to colonoscopy. Major morbidity considered to be definitely related to colonoscopy occurred in 9 of 3196 procedures (0.3%): lower GI bleeding requiring intervention (6), myocardial infarction and/or cerebrovascular accident (2), and thrombophlebitis (1). In subjects undergoing only diagnostic procedures, the major complication rate was 0.1%. CONCLUSIONS: Screening colonoscopy can be performed in multiple centers with a high degree of success and safety in large numbers of asymptomatic, average-risk men.

Aged↗