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Biomedical subjects

D K Rex

Publications and source records attributed to D K Rex.

At least 19 recordsLinked to original sources
PubMed1996

Colonoscopy evaluations: justification by cost?

The type of colonic imaging (radiological vs colonoscopic) for evaluating symptomatic patients without evidence of bleeding in both an efficacious and cost-conserving manner has become a very debated issue. In a randomized, controlled clinical trial, the authors hoped to examine the prevalence of neoplasm and the effectiveness and cost-effectiveness of initial diagnostic strategies of colonoscopy versus flexible sigmoidoscopy and air contrast barium enema in patients without evidence of intestinal bleeding. One hundred forty-nine patients over the age of 40 with symptoms suggestive a colonic disease without evidence of bleeding (no hematechezia, negative test for fecal occult blood, and normal serum hemoglobin) were randomized to undergo either initial colonoscopy or flexible sigmoidoscopy plus barium enema. Patients with incomplete lower GI tests were referred for the corresponding alternative imaging modality. Cost analyses using sensitivity analysis were performed. Baseline information with respect to age, race, sex, inpatient status, reason for referral, mean weight loss, hemoglobin, blood urea nitrogen, and albumin were similar in both groups. Eighteen patients (24%) who initially received air contrast barium enema and flexible sigmoidoscopy then required colonoscopy, whereas only five patients (6%) who initially underwent colonoscopy first required air contrast barium enema plus flexible sigmoidoscopy. The study found that: a) The prevalence of cancer in the study was low (one of 149 patients); b) initial colonoscopy detected more persons with adenomas than that of air contrast barium enema plus flexible sigmoidoscopy (23 of 75 patients vs 13 of 74 patients, odds radio, 2.07, CI,0.90-4.92; this approached significance); and c) air contrast barium enema plus flexible sigmoidoscopy detected more diverticulosis (46 of 74 patients vs 31 of 75 patients, odds ratio, 0.41, 95% CI, 0.21-0.87). The significant conclusions were that patients undergoing flexible sigmoidoscopy plus air contrast barium enema were more likely to undergo alternative procedures and that sensitivity analysis suggested that, for most areas in the United States, initial colonoscopy would be more cost-effective for the outcome of detection of adenomas (1).

Barium Sulfate↗
PubMed1995

Flexible sigmoidoscopy plus air-contrast barium enema versus colonoscopy for evaluation of symptomatic patients without evidence of bleeding.

One hundred forty-nine patients aged 40 years or more with symptoms suggestive of colonic disease but without evidence of gastrointestinal bleeding (absence of hematochezia, normal serum levels of hemoglobin, and at least one test negative for fecal occult blood) were randomized to undergo either initial colonoscopy or initial flexible sigmoidoscopy plus air-contrast barium enema. Patients with incomplete initial colonoscopy and certain patients with polyps seen on flexible sigmoidoscopy plus barium enema underwent the alternative procedure (barium enema or colonoscopy). The main results were as follows: First, the overall prevalence of cancer in the study was very low (0.67%). Second, initial flexible sigmoidoscopy plus barium enema detected more patients with diverticulosis than did initial colonoscopy (46% versus 31%; p = .01). Initial colonoscopy detected more persons with adenomas (p = .06) than did initial flexible sigmoidoscopy plus barium enema. Patients undergoing initial flexible sigmoidoscopy plus barium enema require the alternative procedure (24%) than were patients undergoing initial colonoscopy (6%; p = .002). Third, sensitivity analyses suggested that for most areas in the United States, initial colonoscopy would be more cost-effective for the outcomes of detection of adenomas and detection of large adenomas, although very few patients in the study had large adenomas. We conclude that the prevalence of colorectal cancer in persons with colonic symptoms but no evidence of bleeding is low and is comparable with the prevalence in an asymptomatic population. Cost-effective selection of imaging strategies in this population can be based on demographic factors such as age and sex, which are better predictors of the presence of adenomas than are symptoms.

Adenoma↗
PubMed1995

Does routine intravenous glucagon administration facilitate colonoscopy? A randomized trial.

BACKGROUND: Previous studies on the routine use of glucagon in colonoscopy have produced conflicting results. METHODS: Two separate studies were performed. In one study (Study 1), 80 consecutive patients were randomized after cecal intubation to receive 1 mg glucagon (n = 41) or placebo (n = 39), intravenously, in double-blind fashion. In a second study (Study 2) 90 sedated patients undergoing colonoscopy were randomized to receive 1 mg glucagon (n = 46) or placebo (n = 44), intravenously, just before colonoscope insertion. In each study, colonoscope insertion and withdrawal time, therapeutic intervention time, the presence and severity of colonic spasm, colonoscopy yield, and side effects were recorded. RESULTS: Mean withdrawal time in Study 1 was similar in those receiving glucagon (6.85 min) and in those receiving placebo (6.92 min). Mean insertion time in Study 2 (5.07 min) was identical between groups. Spasm scores and colonoscopy yield did not differ between glucagon and placebo in either study. There was a trend toward more side effects (nausea and vomiting) with glucagon in Study 1. Glucagon did not facilitate insertion or withdrawal in the subset of patients with diverticulosis. CONCLUSIONS: Routine use of intravenous glucagon in a dosage of 1 mg does not facilitate colonoscopy by experienced examiners.

Adult↗
PubMed1995

Prevalence and natural history of colonic angiodysplasia among healthy asymptomatic people.

OBJECTIVE: The prevalence of colonic angiodysplasia (AD) among healthy asymptomatic people is unknown, and the natural history of these lesions has not been clearly defined. The purpose of our study was to determine prevalence and to review and assess the natural history of AD. METHODS: Each of the authors had previously published his own prospective study that involved screening colonoscopy for the detection of neoplasia in asymptomatic adult men and women who had never bled. All pathological lesions diagnosed by endoscopy were recorded, but only data pertaining to polyps were published. We pooled and analyzed the endoscopic findings (raw data) from those studies and assessed the natural history of the lesions by reviewing the medical charts of affected subjects to determine whether bleeding had occurred. Nine hundred sixty-four patients were evaluated (mean age, 62 yr). All were > or = 50 yr old (range, 50-79 yr), not anemic, Hemoccult negative, asymptomatic, and had full colonoscopy to the cecum. RESULTS: Eight subjects had AD (prevalence, 0.83%). Lesions in affected individuals were usually small (mean size, 4.0 mm) and most often were located in the right colon (62%). No subject bled, and all maintained a stable hemoglobin (mean, 14.6 g%) with a mean follow-up of 3 yr. CONCLUSIONS: We conclude that 1) colonic AD is uncommon among healthy asymptomatic people (prevalence, 0.83%), 2) lesions are usually small (< 10 mm) and are located proximal to the hepatic flexure, 3) the natural history for AD in these people is benign, and the risk of bleeding over a 3-yr period is low (0% in 3 yr), and 4) because of this low risk, endoscopic treatment for incidental (nonbleeding) AD is unnecessary.

Aged↗
PubMed1995

Colonoscopy: a review of its yield for cancers and adenomas by indication.

Colonoscopy for bleeding indications (positive fecal occult blood test, emergent or nonemergent rectal bleeding, melena with a negative upper endoscopy and iron deficiency anemia) has a substantial yield for cancers (1 per 9 to 13 colonoscopies), although slide rehydration of fecal occult blood tests decreases the yield (1 per 45 colonoscopies). Prospective studies indicate that nonbleeding colonic symptoms have a substantially lower yield for cancer than bleeding symptoms (1 per 109 colonoscopies). Patients with indications for screening colonoscopy with a relatively high yield of cancer are those with Lynch syndrome (1 per 39 colonoscopies) and males more than 60 yr old (1 per 64 colonoscopies). Perioperative colonoscopy in persons undergoing colorectal cancer resection has a high yield for synchronous cancer (2-3%). An initial examination in persons with long-standing ulcerative colitis has a high yield for cancer (12%). Surveillance colonoscopy after cancer resection has an intermediate yield for anastomotic cancer (1 per 74 procedures) and metachronous cancers (1 per 82 colonoscopies), although this number may overestimate the yield of metachronous cancer. Postpolypectomy surveillance and ulcerative colitis surveillance colonoscopy have relatively low yields for cancer (1 per 317 and 360 colonoscopies, respectively). However, postpolypectomy surveillance colonoscopy, in combination with initial clearing colonoscopy, has been proven to be almost entirely effective in preventing colorectal cancer death. Further, cancer yields for postpolypectomy surveillance should improve with implementation of new surveillance guidelines, with little or no impact on mortality. The effectiveness of ulcerative colitis surveillance is less certain. Referral of patients with low-grade dysplasia for colectomy would improve the value and effectiveness of surveillance colonoscopy in ulcerative colitis. Adenoma yields at colonoscopy are relatively independent of indication, as evidenced by the high yield of adenomas in screening colonoscopy studies. Demographic factors, including increasing age and male gender, are important predictors of adenomas at initial colonoscopy. Age, male gender, and multiple and large adenomas at initial examination are predictors of adenomas at subsequent postpolypectomy surveillance. Persons with ureterosigmoidostomies can be screened by interval flexible sigmoidoscopy and do not require screening colonoscopy. A history of breast cancer does not predict an improved yield of colonoscopic screening compared to average-risk persons.

Adenoma↗
PubMed1994

The yield of a second screening flexible sigmoidoscopy in average-risk persons after one negative examination.

BACKGROUND/AIMS: The American Cancer Society recommends that asymptomatic persons aged > or = 50 years undergo sigmoidoscopy every 3-5 years. However, the yield of a second examination 3 years later in persons who are initially negative is unknown. The aim of this study was to determine the yield of a second flexible sigmoidoscopy in average-risk persons aged > or = 50 years after an initial negative examination. METHODS: Two hundred fifty-nine asymptomatic, average-risk persons who had undergone a negative screening flexible sigmoidoscopy examination at age > or = 50 years underwent a second examination at least 2 years later (mean, 3.4 years). RESULTS: The second examination found adenomas in 15 (6%) screenees, but no cancers or large (> 1 cm) or severely dysplastic adenomas were detected. Persons aged > or = 60 years at the time of the second examination were more likely (10%) to have adenomas than those < 60 years (3%) (odds ratio, 3.76; 95% confidence interval, 1.17-12.2), but no advanced lesions were found in persons aged > or = 60 years. CONCLUSIONS: These data suggest that the American Cancer Society should consider changing its recommendation for screening flexible sigmoidoscopy in asymptomatic, average-risk persons to 5-year intervals after a negative examination.

Adenoma↗
PubMed1994

Acute colonic pseudo-obstruction (Ogilvie's syndrome).

Acute colonic dilation without mechanical obstruction (Ogilvie's syndrome) was first described in 1948. The pathogenesis remains unknown but likely involves imbalance between sympathetic and parasympathetic colonic innervation. Patients are generally hospitalized with another serious illness when the syndrome develops. There are no controlled data on the efficacy of any therapy. A trial of conservative measures alone is appropriate in a subset of patients who lack significant abdominal pain, peritoneal findings, and who have one or more potential underlying factors that are reversible. Colonoscopy is the initial invasive therapeutic maneuver but fails in 31% of patients and is followed by recurrence in 40% of those in whom initial decompression is successful. Placement of a tube during colonoscopy may help to prevent recurrence. No pharmacological therapy is proven effective, although anecdotal successes with some agents suggest clinical trials that should be performed. A minority of patients still require surgical cecostomy, which has been recently performed via laparoscopy.

Cecostomy↗
PubMed1994

Colonoscopy.

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Colonoscopy↗
PubMed1994

An etiologic approach to management of duodenal and gastric ulcers.

With rare exception, peptic ulcers can now be classified as either Helicobacter pylori-related, induced by nonsteroidal anti-inflammatory drugs (NSAIDs), or related to Zollinger-Ellison syndrome. Helicobacter pylori-related ulcers can be treated by eradication of H pylori or by traditional therapies, including antisecretory drugs or sucralfate. Successful eradication of H pylori requires compliance with a multidrug regimen. Therefore, candidates should demonstrate substantial motivation. In general, the greater the degree of ulcer recurrence or resistance, the stronger the indication for H pylori eradication. Sucralfate is effective in healing H pylori-related duodenal ulcers, and H2 receptor antagonists heal H pylori-related duodenal and gastric ulcers. Omeprazole provides faster healing of H pylori-related ulcers, and is particularly useful in treating large gastric ulcers. Dyspepsia induced by NSAIDs and NSAID-related endoscopic erosions are managed by stopping NSAID use or reducing the dosage; administering NSAIDs with meals; and administering H2 receptor antagonists in full split-doses. NSAID-induced duodenal ulcers and small gastric ulcers can be healed with full split-doses of H2 receptor antagonists, even while the NSAID is continued. Large (> 5 mm) NSAID-induced gastric ulcers are most efficiently treated with omeprazole, particularly if the patient continues to take the NSAID.

Anti-Bacterial Agents↗
PubMed1993

Colonic adenomas in asymptomatic women with a history of breast cancer.

One hundred ninety-three asymptomatic women with a personal history of breast cancer underwent screening colonoscopy. One hundred sixty-eight women had breast cancer as their only potential risk factor for colonic neoplasia, and 25 had a family history of colorectal neoplasia in addition to their personal history of breast cancer. Among women with breast cancer, increasing age and body weight were each predictive of an increasing prevalence of colonic adenomas. The prevalence of colonic adenomas in women aged 50-75 yr whose only potential risk factor was breast cancer was 18%, and was identical to the prevalence of colonic adenomas in 186 asymptomatic average-risk control women aged 50-75 yr (odds ratio 1.0, 95% CI 0.54-1.87). We conclude that a personal history of breast cancer does not predict a higher prevalence of colonic adenomas.

Adenoma↗
PubMed1993

Right upper quadrant abdominal pain. Diagnosis in patients without evident gallstones.

Right upper quadrant abdominal pain is often of biliary origin. Negative results on an ultrasound examination do not exclude biliary pathology. A logical diagnostic approach to the patient should be based on clues obtained from careful history taking, physical examination, and review of routine laboratory studies. Endoscopy, radiography, and nuclear medicine studies may identify specific causes for pain. The use of sophisticated tests, such as endoscopic retrograde cholangiopancreatography with sphincter manometry, may enable diagnosis in refractory cases. Therapy specific for a correctly diagnosed cause provides rewarding results and avoids unnecessary and unsuccessful procedures.

Abdominal Pain↗
PubMed1993

Colonic neoplasia in asymptomatic persons with negative fecal occult blood tests: influence of age, gender, and family history.

Six hundred twenty-one asymptomatic persons with negative fecal occult blood tests (ages 50-75 yr), including 496 with no known risk factors for colorectal cancer and 125 with a single first-degree relative with a history of colonic neoplasia developed after age 40, underwent screening colonoscopy. Three Dukes A cancers were detected in average-risk persons. The overall prevalence of adenomatous polyps was 27%. Multiple logistic regression analysis revealed that increasing age and male gender were both strong predictors of colonic neoplasia (p < 0.001). A positive family history of a single first-degree relative with colorectal cancer was not associated with an increased prevalence of colonic neoplasia (p = 0.29), although an effect may be present if the relative was < 60 yr at diagnosis. Overall 16% of males and 7% of women > or = 60 yr had at least one adenoma that was large (> or = 1 cm in size), villous or tubulovillous, or had grade 3 dysplasia. We conclude that the prevalence of colonic neoplasia in asymptomatic persons with negative fecal occult blood tests is substantial, particularly in elderly males. A family history of a single first-degree relative diagnosed at age > or = 60 yr with colorectal cancer is not associated with an increased prevalence of colonic adenomas.

Adenoma↗
PubMed1992

Chronic constipation with encopresis persisting beyond 15 years of age.

Childhood constipation with encopresis is a common malady. Previous reports suggest that essentially all patients either respond to standard treatments or have spontaneous recovery before 16 years of age. In this paper, we describe the results of anorectal function studies and treatment outcome in four patients in whom constipation and encopresis persisted beyond 15 years of age. Abnormalities in the ability to defecate water-filled balloons, in external sphincter relaxation with straining, in rectal sensation and development of the urge to defecate, and in maximum anal resting pressure were seen in some or all of these patients. In addition, two patients had impaired voluntary squeeze strength. Two patients responded to standard therapy; a colostomy was needed in one; and one failed therapy and has become a recluse.

Adolescent↗