Search PubMed⌕ Search

Biomedical subjects

D K Rex

Publications and source records attributed to D K Rex.

At least 19 recordsLinked to original sources
PubMed2006

Review article: moderate sedation for endoscopy: sedation regimens for non-anaesthesiologists.

BACKGROUND: Moderate sedation is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands with or without light tactile stimulation. Moderate sedation is typically accepted in the anaesthesia community as an appropriate target for sedation by non-anaesthesiologists. AIM: To describe drug regimens that can be successfully and safely targeted to moderate sedation for endoscopy by non-anaesthesiologists. RESULTS: Moderate sedation can be achieved using narcotics and benzodiazepines. There is interest in some countries in propofol for endoscopy, which is often viewed as an agent for deep sedation. Indeed, propofol cannot be targeted to moderate sedation for endoscopy as a single agent because of coughing during upper endoscopy and pain withdrawal responses during colonoscopy. Pre-treatment with low doses of narcotic and/or benzodiazepine blocks these effects, allowing propofol to be targeted to moderate sedation. Fospropofol, a prodrug of propofol in clinical development, can also be targeted to moderate sedation if co-administered with narcotic. CONCLUSION: Moderate sedation provides a safety margin when compared with deep sedation and general anaesthesia. Development of protocols that target agents such as propofol to moderate sedation will expand the sedation agents available to non-anaesthesiologists and help ensure that this expansion occurs safely.

Anesthesia↗
PubMed2005

Efficacy and tolerability of a new formulation of sodium phosphate tablets (INKP-101), and a reduced sodium phosphate dose, in colon cleansing: a single-center open-label pilot trial.

BACKGROUND: The tablet form of sodium phosphate for bowel preparation for colonoscopy contains microcrystalline cellulose. This inactive ingredient produces a residue that obscures mucosal visualization and is time-consuming to remove during colonoscopy. AIM: To perform an open-label study of efficacy and tolerability of a modified formulation with microcrystalline cellulose reduced by 50% (code named INKP-101) and a lower total dose of sodium phosphate. METHODS: Patients scheduled for colonoscopy self-administered 28 INKP-101 tablets (42 g sodium phosphate). Colon cleansing efficacy was evaluated using a standard 4-point scoring system and the amount of microcrystalline cellulose present and time spent removing it using an 8-point scale. RESULTS: A total of 31 patients were screened and enrolled. Thirty patients had a colonoscopy and were evaluated for colon cleansing efficacy. Overall colon cleansing was rated as excellent and good in 90% and 10% of patients respectively. About 77% of patients had microcrystalline cellulose scores of 2 or 3 (corresponding to <1 or 1-2 min spent removing microcrystalline cellulose, respectively). The drug was well-tolerated and adverse events were generally benign. CONCLUSION: A new formulation of sodium phosphate with reduced microcrystalline cellulose and a lower total dose of sodium phosphate was effective for colonoscopy and well-tolerated.

Adult↗
PubMed2005

Quality in the technical performance of screening flexible sigmoidoscopy: recommendations of an international multi-society task group.

BACKGROUND: Flexible sigmoidoscopy (FS) is a complex technical procedure performed in a variety of settings, by examiners with diverse professional backgrounds, training, and experience. Potential variation in technical quality may have a profound impact on the effectiveness of FS on the early detection and prevention of colorectal cancer. AIM: We propose a set of consensus and evidence based recommendations to assist the development of continuous quality improvement programmes around the delivery of FS for colorectal cancer screening. RECOMMENDATIONS: These recommendations address the intervals between FS examinations, documentation of results, training of endoscopists, decision making around referral for colonoscopy, policies for antibiotic prophylaxis and management of anticoagulation, insertion of the FS endoscope, bowel preparation, complications, the use of non-physicians as FS endoscopists, and FS endoscope reprocessing. For each of these areas, continuous quality improvement targets are recommended, and research questions are proposed.

Antibiotic Prophylaxis↗
PubMed2004

Review article: registered nurse-administered propofol sedation for endoscopy.

Propofol has several attractive properties that render it a potential alternative sedative agent for endoscopy. Compared with meperidine and midazolam, it has an ultra-short onset of action, short plasma half-life, short time to achieve sedation, faster time to recovery and discharge, and results in higher patient satisfaction. Shorter times to achieve sedation enhance efficiency in the endoscopy unit. Multiple studies have documented the safe administration of propofol by non-anaesthesiologists. Administration by registered nurses is more cost-effective than administration by anaesthesiologists. However, the administration of propofol by a registered nurse supervised only by the endoscopist is controversial because the drug has the potential to produce sudden and severe respiratory depression. More information is needed on how training nurses and endoscopists should proceed to give propofol, as well as the optimal level of monitoring to ensure the safety of nurse-administered propofol.

Endoscopy↗
PubMed2002

Safety and efficacy of two reduced dosing regimens of sodium phosphate tablets for preparation prior to colonoscopy.

OBJECTIVES: To evaluate the safety and efficacy of two reduced dosing regimens of sodium phosphate tablets (Visicol, InKine Pharmaceutical Co. Inc., Blue Bell, PA, USA) for colon cleansing prior to colonoscopy. METHODS: In a randomized, multicentre, endoscopist-blinded clinical study, adults undergoing colonoscopy received either 28 tablets (42 g) or 32 tablets (48 g) of sodium phosphate for colon cleansing. The endoscopist used a validated four-point scale to rate the overall quality of colon cleansing, as well as cleansing in the ascending colon. Adverse events were collected and evaluated. RESULTS: The quality of overall colon cleansing was 'excellent' or 'good' in 84% or more of both groups, with no significant difference between the two doses. No patient had a preparation rated as 'inadequate' or required a repeat procedure. All patients were able to complete the assigned dose of tablets, and there were no deaths, serious adverse events or dropouts from the study. CONCLUSIONS: A reduced tablet regimen for sodium phosphate tablets, using either 28 or 32 tablets, is well tolerated and effective for colon cleansing prior to colonoscopy.

Cathartics↗
PubMed2001

Effect of variable stiffness colonoscopes on cecal intubation times for routine colonoscopy by an experienced examiner in sedated patients.

BACKGROUND AND STUDY AIMS: Variable-stiffness colonoscopes allow passage of the rectosigmoid colon in a flexible mode, followed by stiffening to prevent looping. This feature might allow faster cecal intubation. PATIENTS AND METHODS: Consecutive patients without previous colonic or rectal resection, inflammatory bowel disease, or anticipated need for either a pediatric or standard insertion tube were evaluated. Four Olympus colonoscopes, including a standard "adult" insertion-tube diameter variable-stiffness colonoscope (VSA), a pediatric variable-stiffness colonoscope (VSP), a standard "adult" colonoscope (CF-140) (SA), and a standard "pediatric" colonoscope (PCF-140) (SP) were used in rotation. RESULTS: Among 358 consecutive patients, 99.2% of exams were complete to the cecum. The stiffening device was activated in 61% and 80% of the adult and pediatric variable-stiffness examinations, respectively. The examiner judged the device to be very useful, somewhat useful, and of no help in 46%, 44%, and 10% of VSA colonoscope examinations and 55%, 33%, and 12% of VSP colonoscope examinations. However, the mean cecal insertion time was 4.04 minutes, with no difference between the four colonoscopes (P=0.98). The percentage of intubations in < 2 minutes was 15.4%, 2-3 minutes 25.9%, 3-4 minutes 19.1%, 4-5 minutes 16.0%, and >5 minutes 23.7%, with no significant difference between the colonoscopes. CONCLUSIONS: Variable-stiffness colonoscopes were frequently judged useful by an experienced examiner but did not impact cecal intubation times in sedated patients. Additional studies by other experienced and inexperienced examiners, as well as evaluation of additional technical improvements and evaluation in unsedated patients, are needed.

Biomechanical Phenomena↗
PubMed2001

Inflammatory bowel disease.

The pathogenesis of inflammatory bowel disease (IBD) continues to be explored, with the emphasis on genetically determined host immune dysregulation as it applies to interactions with luminal bacteria. The role of endoscopic ultrasound in the evaluation of IBD continues to be studied. Recent advances in the evaluation of enterocutaneous fistulas have been made through the use of hydrogen peroxide to enhance definition of the fistula course and characteristics of the neighboring bowel, as evaluated by transabdominal ultrasound. Refinements have been made in the use and interpretation of the results of surveillance colonoscopy for detection of colorectal cancer and dysplasia in IBD, but a consistent approach still needs to be applied by individual practitioners. New data exist on the usefulness of methotrexate for maintenance of remission, while a lack of efficacy has been demonstrated for mesalamine in the prevention of postoperative recurrence. The role of anti-tumor necrosis factor (TNF) antibody therapy in the treatment of IBD continues to be investigated.

Colonoscopy↗
PubMed2001

Medical-legal risks of incident cancers after clearing colonoscopy.

Colonoscopy and polypectomy effectively reduce the incidence and mortality of colorectal cancer, but some patients present with fully developed cancers within 1-4 yr of a colonoscopy that apparently cleared the colon of neoplasia. These events may result in medical-legal action against colonoscopists, generally based on an assumption of negligent technical performance of the procedure. Alternative explanations for the development of interval cancers include variable growth rates of colorectal cancers, the inherent miss rate of the procedure even when optimal examination techniques are used, and the possibility of flat lesions that are not readily detected by standard colonoscopic techniques. This paper discusses issues relevant to reduction of medical-legal risks associated with interval cancers after clearing colonoscopy. These issues include informed consent, documentation of cecal intubation, appropriate description of preparation, documentation of examination time and technique, and attention to potential atypical neoplasms.

Colonic Neoplasms↗
PubMed2001

Surveillance colonoscopy following resection of colorectal polyps and cancer.

Patients undergoing clearing colonoscopy with resection of adenomas should generally have their next examination at three years. Exceptions include large sessile adenomas removed piecemeal (re-examine at two to six months until no evidence of recurrent polyp, then at one year), average risk patients with a single tubular adenoma (next examination at five years) and patients with 'numerous' adenomas (next examination at one or two years). Patients with surgically resected colorectal cancer should have a clearing colonoscopy preoperatively or within two to three months of surgery in obstructed patients, even if the preoperative barium enema is negative for proximal lesions. After the clearing colonoscopy, subsequent examinations can be performed based on the associated adenoma findings.

Colonic Polyps↗
PubMed2001

Colorectal cancer screening and surveillance: the present and the future.

Colorectal cancer screening is now proven to be effective and is widely endorsed by guidelines committees. Several forms of screening have merit, but the screening tests used in individual patients are often dictated by insurers. The use of screening colonoscopy is expected to increase. Gastroenterologists will play the central role in ensuring the safe and cost-effective application of colonoscopy to screening and surveillance.

Barium Sulfate↗
PubMed2000

Screening colonoscopy in asymptomatic average-risk African Americans.

BACKGROUND: Recent data indicate that colorectal cancer incidence and mortality in white Americans have been declining since 1985 at a rate of 2% to 3% per year. In African Americans, however, mortality from colorectal cancer appears to be increasing. We sought to evaluate the prevalence of colonic neoplasia in asymptomatic African Americans. METHODS: We performed a cross-sectional colonoscopy screening study to determine the prevalence of colonic neoplasia in asymptomatic African Americans older than 50 years of age. RESULTS: One hundred sixty-six subjects were evaluated for the study of whom 121 (69 women) were deemed to be asymptomatic average-risk persons and completed colonoscopy. Forty-two individuals (35%) had a total of 72 adenomas (67 tubular and 5 tubulovillous); 47 (65.3%) of these were proximal to the splenic flexure. Three subjects had an adenoma 1 cm or greater in diameter and none had severe dysplasia. CONCLUSIONS: The overall prevalence of adenomas in asymptomatic average-risk African Americans was comparable to that of previously described populations. The predominance of right-sided adenomas in this study confirms previous findings and is an area requiring further study. Until this issue is resolved, we suggest the use of colonoscopy rather than sigmoidoscopy for screening for colorectal neoplasia in asymptomatic, average-risk African Americans.

Adenomatous Polyps↗
PubMed2000

Colonoscopic withdrawal technique is associated with adenoma miss rates.

BACKGROUND: Clinical studies have documented differences in detection rates of colorectal cancers and adenomas between experienced colonoscopists, the basis of which is unknown. The aim of this study was to determine whether colonoscopic withdrawal technique varies between 2 colonoscopists with known differences in adenoma detection rates. METHODS: Ten consecutive colonoscopic withdrawals by each of the 2 colonoscopists were videotaped and then assessed according to specific criteria by 4 experts blinded to who had performed the colonoscopies. RESULTS: Each of the 4 experts scored the colonoscopist with the lower miss rate significantly higher (p < 0.001) for each of 4 quality criteria: (1) examining the proximal sides of flexures, folds and valves, (2) cleaning and suctioning, (3) adequacy of distention, and (4) adequacy of time spent viewing. CONCLUSION: Higher quality colonoscopic withdrawal technique as determined by expert observers was associated with a colonoscopist with a previously documented lower miss rate for adenomas. Colonoscopic withdrawal technique should be subjected to further study and standards for withdrawal technique should be developed.

Adenoma↗
PubMed2000

Still photography versus videotaping for documentation of cecal intubation: a prospective study.

BACKGROUND: Documentation of cecal intubation is important for credentialing and continuous quality improvement. However, convincing cecal photographs can be difficult to obtain. The aims of the study were to determine (1) the anatomic variations and photographic factors associated with convincing cecal photographs; (2) whether a prospective attempt to capture specific features resulted in more convincing photographs; and (3) how a prospective attempt at capturing convincing cecal features during still photography compares with videotaping as a method of documenting cecal intubation. METHODS: A single examiner evaluating 165 consecutive patients photographed the entire cecum from just distal to the ileocecal valve, the appendiceal orifice, the ileocecal valve orifice, and in the last 110 consecutive cases, the terminal ileum, if it could be intubated. The photographs were then scored by 8 experts according to how convinced they were that cecal intubation had occurred. Features associated with high and low scores were determined, and 50 additional consecutive patients were photographed with a specific effort to capture these features, along with videotaping of the cecum. These photographs and videotapes were then scored by 7 of the 8 experts on a scale of 1 to 5, with 5 representing "definitely the cecum." RESULTS: There was marked variation in scores of still photographs among reviewers. A combination of photographs produced the highest mean score and the highest percentage of scores that were either "probably" or "definitely" of the cecum. The photograph of the cecum from just distal to the ileocecal valve was most convincing and the terminal ileum photograph was least convincing. In the 50 cases in which an attempt was made to capture specific features, mean scores improved for the overall cecal photograph by 0.10, the appendiceal orifice by 0.23, the ileocecal valve lips by 0.20, and the terminal ileum by 0. 19. The cecum, appendiceal orifice, valve lips, and terminal ileum photographs for the last 50 patients were scored higher than those from the first 165 patients by 4, 4, 4, and 5 reviewers, respectively. Videotapes were consistently convincing (overall mean score 4.78 out of 5) and were scored more convincing than the combination of still photos from the final 50 cases by 6 of 7 reviewers. CONCLUSIONS: Still photography of the cecum can be improved somewhat by attempting to capture specific cecal features. However, because of anatomic variation among normal individuals, still photography remains inconsistently convincing. A combination of photographs is most convincing. Videotaping of the cecum is consistently convincing and would appear to serve effectively as a means of documenting cecal intubation rates for the purposes of continuous quality improvement and credentialing.

Cecum↗