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Biomedical subjects

D B Nelson

Publications and source records attributed to D B Nelson.

At least 37 records · Page 2Linked to original sources
PubMed2000

A randomized, controlled trial of transcutaneous carbon dioxide monitoring during ERCP.

BACKGROUND: Pulse oximetry, used to monitor oxygen saturation during endoscopy, does not directly measure hypoventilation. Study goals were to determine whether transcutaneous carbon dioxide (PtcCO(2)) monitoring during endoscopic retrograde cholangiopancreatography (ERCP) prevents severe hypoventilation and to assess the accuracy of clinical observation and pulse oximetry in detecting hypoventilation. METHODS: All patients received intensive clinical and electronic monitoring including pulse oximetry. Supplemental oxygen was administered for pulse oximetry < 90%. Patients were randomized to a treatment arm (group 1) where PtcCO(2) monitoring guided sedation or a control arm (group 2) where PtcCO(2) was recorded but unavailable for guiding sedation. RESULTS: Group 1 had significantly fewer episodes of severe carbon dioxide retention (rise in PtcCO(2) >/=40 mm Hg above baseline) than group 2 (0 of 199 versus 5 of 196, respectively, p = 0.03), as well a shorter mean duration of procedure discomfort (8.3% of procedure duration rated as "uncomfortable" versus 11.5%, p = 0.04). Correlations between clinical observation and objective measures of ventilation were poor: level of sedation versus PtcCO(2) (R = 0.3) or pulse oximetry (R = 0.06); slowest respiratory rate versus PtcCO(2) (R = 0.4) or pulse oximetry (R = -0.4). PtcCO(2) rises of greater than 20 mm Hg occurred without oxygen desaturation in 10.7% of patients receiving supplemental oxygen. CONCLUSIONS: Carbon dioxide retention during ERCP is not reliably detected by clinical observation or by pulse oximetry in patients receiving supplemental oxygen. The addition of PtcCO(2) monitoring prevents severe carbon dioxide retention more effectively than intensive clinical monitoring and pulse oximetry alone. The clinical relevancy of this observation needs to be determined in an appropriately designed outcome study.

Blood Gas Monitoring, Transcutaneous↗
PubMed2000

Dyspepsia is associated with CagA-positive Helicobacter pylori.

OBJECTIVE: The role of Helicobacter pylori in nonulcer dyspepsia is controversial. Speculation has arisen that only strains of H. pylori carrying the CagA virulence factor are important in the development of dyspepsia. The objective of this study was to determine whether nonulcer dyspepsia correlated with CagA-positive H. pylori infection. METHODS: A total of 435 healthy blood donors and 102 general medicine clinic respondents completed the Bowel Disease Questionnaire and the PRIME-MD survey, a validated screen for common psychiatric disorders. Subjects were classified as cases of nonulcer dyspepsia if they reported pain in the upper abdomen more than six times in the previous year and denied a past or current history of peptic ulcer disease. Study participants were tested for IgG antibodies to H. pylori and the CagA protein. RESULTS: Clinic respondents were more likely than healthy blood donors to meet the case definition for nonulcer dyspepsia (34% vs 13%, p < 0.001), to be seropositive for H. pylori (54% vs 18%, p < 0.001), and to be CagA seropositive (41% vs 10%, p = 0.01). Logistic regression identified CagA seropositivity (p = 0.03), race (p = 0.001), and positive screens for depression (p = 0.007) or somatization (p < 0.001) as variables independently associated with nonulcer dyspepsia. CONCLUSION: Infection with a CagA-positive strain of H. pylori is associated with a clinical diagnosis of nonulcer dyspepsia. However, nonulcer dyspepsia was also strongly and independently associated with positive screens for depression or somatization disorder as well as with ethnicity. These potential sources of variance should be considered in the design of future studies evaluating nonulcer dyspepsia.

Adult↗
PubMed1999

Same-day discharge after endoscopic biliary sphincterotomy: observations from a prospective multicenter complication study. The Multicenter Endoscopic Sphincterotomy (MESH) Study Group.

BACKGROUND: Same-day discharge after endoscopic biliary sphincterotomy (ES) is a common clinical practice, but there have been few data to guide appropriate selection of patients. Using a prospective, multicenter database of complications, we examined outcomes after same-day discharge as it was practiced by a variety of endoscopists and evaluated the ability of a multivariate risk factor analysis to predict which patients would require readmission for complications. METHODS: A 150-variable database was prospectively collected at time of ES, before discharge and again at 30 days in consecutive patients undergoing ES at 17 centers. Complications were defined by consensus criteria and included all specific adverse events directly or indirectly related to ES requiring more than 1 night of hospitalization. RESULTS: Six hundred fourteen (26%) of 2347 patients undergoing ES were discharged on the same day as the procedure, ranging from none at 6 centers to about 50% at 2 centers. After initial observation and release, readmission to the hospital for complications occurred in 35 (5.7%) of 614 same-day discharge patients (20 pancreatitis and 15 other complications, 3 severe). Of the same-day discharge patients, readmission was required for 14 (12.2%) of 115 who had at least one independently significant multivariate risk factor for overall complications (suspected sphincter of Oddi dysfunction, cirrhosis, difficult bile duct cannulation, precut sphincterotomy, or combined percutaneous-endoscopic procedure) versus 21 (4.2%) of 499 without a risk factor (odds ratio 3.1: 95% confidence interval [1.6, 6.3], p < 0.001). Of complications presenting within 24 hours after ES, only 44% presented within the first 2 hours, but 79% presented within 6 hours. CONCLUSIONS: Same-day discharge is widely utilized and relatively safe but results in a significant number of readmissions for complications. For patients at higher risk of complications, as indicated by the presence of at least one of five independent predictors, observation for 6 hours or overnight may reduce the need for readmission.

Adult↗
PubMed1999

Pseudomembranous colitis after itraconazole therapy.

A 53-yr-old man was admitted with new onset of abdominal pain and nonbloody diarrhea 1 month after exposure to the antifungal agent itraconazole. Flexible sigmoidoscopy demonstrated the presence of pseudomembranes, and subsequent evaluation excluded other causes of diarrhea. Disruption of the resident fungal flora of the colon by itraconazole is proposed as the mechanism by which this patient developed pseudomembranous colitis. This association has not previously been reported.

Antifungal Agents↗
PubMed1998

Bacteremia with esophageal dilation.

BACKGROUND: Antibiotic prophylaxis has been recommended for selected patients undergoing esophageal stricture dilation because of a reported high rate of bacteremia. The aim of this study was to determine the rate of bacteremia after esophageal dilatation in a large series and the source of the organisms recovered. METHODS: Blood cultures and oral temperatures were obtained before esophageal dilation and at 5 and 30 minutes after dilation. Dilators were cultured immediately before dilation. Procedural data collected included type of dilation, number of passes, and presence of malignancy. RESULTS: Of 100 procedures in 86 patients undergoing esophageal dilation, 22 (22%) were associated with a positive post-dilation blood culture. Bacteremia was more frequent with dilation of malignant strictures compared with benign strictures (9 of 17 [52.9%] vs. 13 of 83 [15.7%], respectively, p = 0.002) and with passage of multiple dilators compared with passage of a single dilator (16 of 46 [34.8%] versus 6 of 54 [11.1%], respectively, p = 0.007). Bacterial isolates from 22 positive blood cultures matched those from a dilator in only one episode (4.5%). CONCLUSION: The rate of bacteremia after esophageal dilation is 22% and is associated with dilation of malignant strictures or passage of multiple dilators. Organisms cultured from the blood are not transmitted from the dilator.

Bacteremia↗